Roberto Furfaro

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Scholarly Contributions

Books

• Furfaro, R. (2015). Plant production, energy balance and monitoringcontrol-telepresence in a recirculating hydroponic vegetable crop production system: Prototype lunar greenhouse.
• Furfaro, R. (2012). System dynamics and performance factors of a lunar greenhouse prototype bioregenerative life support system.
• Furfaro, R. (2011). An inventory of potentially habitable environments on Mars: Geological and biological perspectives.
• Furfaro, R. (2008). The art of analytical benchmarking.

Chapters

• Furfaro, R. (2011). ASTER imaging and analysis of glacier hazards. In Remote Sensing and Digital Image Processing.

Journals/Publications

• Furfaro, R. (2020). Adaptive generalized ZEM-ZEV feedback guidance for planetary landing via a deep reinforcement learning approach. Acta Astronautica.
• Furfaro, R. (2020). Adaptive guidance and integrated navigation with reinforcement meta-learning. Acta Astronautica.
• Furfaro, R. (2020). Deep Reinforcement Learning for Six Degree-of-Freedom Planetary Landing. Advances in Space Research.
• Furfaro, R. (2020). Least-squares solution of a class of optimal space guidance problems via Theory of Connections. Acta Astronautica.
• Furfaro, R. (2019). A quasi-static approach for the solution of steady-state linear transport problems. Annals of Nuclear Energy.
• Furfaro, R. (2019). Constraining the thermal properties of planetary surfaces using machine learning: Application to airless bodies. Icarus.
• Furfaro, R. (2019). Corrigendum to “Integrated guidance for Mars entry and powered descent using reinforcement learning and pseudospectral method” (Acta Astronautica (2019) 163(PB) (114–129), (S0094576518313043), (10.1016/j.actaastro.2018.12.033)). Acta Astronautica.
• Furfaro, R. (2019). GLAM Bio-Lith RT: A Tool for Remote Sensing Reflectance Simulation and Water Components Concentration Retrieval in Glacial Lakes. Frontiers in Earth Science.
• Furfaro, R. (2019). Integrated guidance for Mars entry and powered descent using reinforcement learning and pseudospectral method. Acta Astronautica.
• Furfaro, R. (2019). Realistic On-the-fly Outcomes of Planetary Collisions: Machine Learning Applied to Simulations of Giant Impacts. Astrophysical Journal.
• Furfaro, R. (2019). Theoretical evaluation of anisotropic reflectance correction approaches for addressing multi-scale topographic effects on the radiation-transfer cascade in mountain environments. Remote Sensing.
• Furfaro, R. (2018). Reactivity determination using the hybrid transport point kinetics and the area method. Annals of Nuclear Energy.
• Furfaro, R. (2018). Surface Composition of (99942) Apophis. The Astronomical Journal.
• Furfaro, R. (2017). Application of Extreme Learning Machines to inverse neutron kinetics. Annals of Nuclear Energy.
• Furfaro, R. (2017). Application of the Transport-Driven Diffusion Approach for Criticality Calculations. Journal of Computational and Theoretical Transport.
• Picca, P., & Furfaro, R. (2017). Application of Extreme Learning Machines to inverse neutron kinetics. Annals of Nuclear Energy, 100, 1--8.
• Picca, P., & Furfaro, R. (2017). Application of the transport-driven diffusion approach for criticality calculations. Journal of Computational and Theoretical Transport, 46 (4), 258-282.
• Furfaro, R., Topputo, F., Mueting, J. R., Casotto, S., & Simo, J. (2016). Analysis and Performance Evaluation of the ZEM/ZEV Guidance and its Sliding Robustification for Autonomous Rendezvous in Relative Motion.
• Mueting, J., Furfaro, R., Topputo, F., & Simo, J. (2016). Optimal Sliding Guidance for Earth-Moon Halo Orbit Station-Keeping and Transfer.
• Picca, P., Furfaro, R., & Ganapol, B. D. (2016). Application of Non-Linear Extrapolations for the Convergence Acceleration of Source Iteration. Journal of Computational and Theoretical Transport, 45(5), 351--367.
• Schiassi, E., Furfaro, R., & Mostacci, D. (2016). Bayesian inversion of coupled radiative and heat transfer models for asteroid regoliths and lakes. Radiation Effects and Defects in Solids, 171(9-10), 736--745.
• Walls, R., Gaylor, D., Reddy, V., Furfaro, R., & Jah, M. (2016). Assessing the IADC Space Debris Mitigation Guidelines: A case for ontology-based data management. AMOS Paper.
• Wibben, D. R., & Furfaro, R. (2016). Optimal sliding guidance algorithm for Mars powered descent phase. Advances in Space Research, 57(4), 948--961.
• Wibben, D. R., & Furfaro, R. (2016). Terminal Guidance for Lunar Landing and Retargeting Using a Hybrid Control Strategy. Journal of Guidance, Control, and Dynamics, 1168--1172.
• Furfaro, R. (2015). Closed-form solution of the first-order Transport-Driven Diffusion approximation. Annals of Nuclear Energy.
• Furfaro, R. (2015). Hovering in asteroid dynamical environments using higher-order sliding control. Journal of Guidance, Control, and Dynamics.
• Furfaro, R. (2015). Model-Based Systems Engineering approach for the development of the science processing and operations center of the NASA OSIRIS-REx asteroid sample return mission. Acta Astronautica.
• Furfaro, R. (2015). Terminal multiple surface sliding guidance for planetary landing: Development, tuning and optimization via reinforcement learning. Journal of the Astronautical Sciences.
• Furfaro, R. (2015). The 2014 earth return of the ISEE-3/ICE spacecraft. Acta Astronautica.
• Furfaro, R. (2014). A hybrid method for the solution of linear Boltzmann equation. Annals of Nuclear Energy.
• Furfaro, R. (2014). Adaptive pinpoint and fuel efficient mars landing using reinforcement learning. IEEE/CAA Journal of Automatica Sinica.
• Furfaro, R. (2014). Hybrid-transport point kinetics for initially-critical multiplying systems. Progress in Nuclear Energy.
• Cersosimo, D., Bellerose, J., & Furfaro, R. (2013). Sliding guidance techniques for close proximity operations at multiple asteroid systems. AIAA Guidance, Navigation, and Control (GNC) Conference.
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  Abstract: Proximity operations at multiple asteroid systems involve higher degrees of complexity due to added perturbations. In this paper, we adapt a Multiple Sliding Surface Guidance (MSSG) algorithm developed for close proximity operations at a single asteroid, and extend its applicability to binary asteroid systems. The advantage of using MSSG is that no trajectory is needed to be computed offine as the commands use the spacecraft accelerations directly. We show simulations of a two-sphere binary systems where the velocity cost and associated transfer times show to be minimal.
• Furfaro, R. (2013). A highly accurate technique for the solution of the non-linear point kinetics equations. Annals of Nuclear Energy.
• Furfaro, R. (2013). Analytical discrete ordinate method for radiative transfer in dense vegetation canopies. Journal of Quantitative Spectroscopy and Radiative Transfer.
• Furfaro, R. (2013). Asteroid precision landing via multiple sliding surfaces guidance techniques. Journal of Guidance, Control, and Dynamics.
• Furfaro, R., Cersosimo, D., & Wibben, D. R. (2013). Asteroid precision landing via multiple sliding surfaces guidance techniques. Journal of Guidance, Control, and Dynamics, 36(4), 1075-1092.
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  Abstract: Autonomous close-proximity operations (hovering, landing) in the low-gravity environment exhibited by asteroids are particularly challenging. A novel nonlinear landing guidance scheme has been developed for spacecraft that are required to execute autonomous closed-loop guidance to a designated point on the asteroid surface. Based on highorder sliding-mode control theory, the proposed multiple sliding surface guidance algorithm has been designed to take advantage of the ability of the system to reach the sliding surface in a finite time. High control activity typical of sliding control design is avoided, resulting in a guidance law that is robust against unmodeled yet bounded perturbations. The proposed multiple sliding surface guidance does not require any off-line trajectory generation, and therefore it is flexible enough to target a large variety of points on the surface without the need of ground-based trajectory analysis. The global stability of the proposed guidance algorithm is proven using a Lyapunov-based approach. The behavior of the multiple sliding surface guidance-based feedback asteroid landing trajectories is investigated via a parametric analysis, and a full set of Monte Carlo simulations in realistic landing scenarios is implemented to evaluate the guidance performance. Based on such results, the multiple sliding surface guidance algorithm is demonstrated to be very accurate and flexible, and it has the potential to be implemented as real-time guidance during asteroid landing and possibly for close-proximity operations. Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Furfaro, R., Gaudet, B., Wibben, D. R., & Simo, J. (2013). Development of non-linear guidance algorithms for asteroids close-proximity operations. AIAA Guidance, Navigation, and Control (GNC) Conference.
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  Abstract: In this paper, we discuss non-linear methodologies that can be employed to devise real-time algorithms suitable for guidance and control of spacecrafts during asteroid close-proximity operations. Combination of optimal and sliding control theory provide the theoretical framework for the development of guidance laws that generates thrust commands as function of the estimated spacecraft state. Using a Lyapunov second theorem one can design non-linear guidance laws that are proven to be globally stable against perturbations with known upper bound. Such algorithms can be employed for autonomous targeting of points of the asteroid surface (soft landing, Touch-And-Go (TAG) maneuvers). Here, we theoretically derived and tested the Optimal Sliding Guidance (OSG) for close-proximity operations. The guidance algorithm has its root in the generalized ZEM/ZEV feedback guidance and its mathematical equations are naturally derived by properly defining a sliding surface as function of Zero-Effort-Miss and Zero-Effort-Velocity. The latter enables the augmentation of the energy-optimal guidance law by a sliding mode that ensures global stability for the proposed algorithm. A set of Monte Carlo simulations in realistic environments are executed to assess the guidance performance in typical operational scenarios found during asteroids close-proximity operations. OSG is shown to satisfy stringent requirements for asteroid pinpoint landing and sampling accuracy.
• Picca, P., & Furfaro, R. (2013). Analytical discrete ordinate method for radiative transfer in dense vegetation canopies. Journal of Quantitative Spectroscopy and Radiative Transfer, 118, 60-69.
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  Abstract: The radiative transfer (RT) in dense vegetation canopies can be approximated via linear Boltzmann equation. However, the directionality of the basic scattering element (i.e. the canopy leaf) makes the medium inherently anisotropic and introduces special features in the definition of both scattering kernel and total cross section. In this paper, a classical methodology for the solution of transport problem, namely the analytical discrete ordinate (ADO) method, is extended to account for the peculiarities of photon transport into dense vegetation canopies. It is demonstrated that the special symmetries arising from modeling the leaf as a bi-Lambertian scatterer, enable the derivation of the ADO equations for canopy transport. Several numerical tests have been performed to evaluate the accuracy of ADO against numerical benchmarks available in the literature. The results show that the proposed methodology is highly accurate, computationally efficient and may set future standards for numerical transport in dense vegetation canopies. © 2013 Elsevier Ltd.
• Adebonojo Jr., B. O., Cupples, M. L., Furfaro, R., & Kidd Jr., J. N. (2012). Launch analyses supporting conceptual human-precursor robotic asteroid missions. Advances in the Astronautical Sciences, 142, 579-594.
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  Abstract: From a set of carefully selected asteroids, a study of conceptual asteroid missions was conducted using a stochastic direct search global optimization process, assuming a set of Key Performance Parameters (KPP's). The key parameters from the best case set included the minimum Escape Energy (C3) as well as the minimum mission total delta V for each asteroid, for both direct and gravity assisted missions. The objective of the current study to determine the launch window times required to achieve ascent and injection onto the outbound trajectory required for either the direct or gravity assisted mission to the selected asteroid, taking into consideration the impact of the range safety limits on the launch azimuths. A set of flyout trajectory orbital elements corresponding to the launch windows will be provided, and a preliminary assessment of the resulting launch vehicle payload delivery capability and margins will be conducted provided based on launch vehicle vendor data.
• Boscheri, G., Kacira, M., Patterson, L., Giacomelli, G., Sadler, P., Furfaro, R., Lobascio, C., Lamantea, M., & Grizzaffi, L. (2012). Modified energy cascade model adapted for a multicrop Lunar greenhouse prototype. Advances in Space Research, 50(7), 941-951.
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  Abstract: Models are required to accurately predict mass and energy balances in a bioregenerative life support system. A modified energy cascade model was used to predict outputs of a multi-crop (tomatoes, potatoes, lettuce and strawberries) Lunar greenhouse prototype. The model performance was evaluated against measured data obtained from several system closure experiments. The model predictions corresponded well to those obtained from experimental measurements for the overall system closure test period (five months), especially for biomass produced (0.7% underestimated), water consumption (0.3% overestimated) and condensate production (0.5% overestimated). However, the model was less accurate when the results were compared with data obtained from a shorter experimental time period, with 31%, 48% and 51% error for biomass uptake, water consumption, and condensate production, respectively, which were obtained under more complex crop production patterns (e.g. tall tomato plants covering part of the lettuce production zones). These results, together with a model sensitivity analysis highlighted the necessity of periodic characterization of the environmental parameters (e.g. light levels, air leakage) in the Lunar greenhouse. © 2012 COSPAR. Published by Elsevier Ltd. All rights reserved.
• Cupples, M. L., Furfaro, R., Hergenrother, C. W., Wibben, D. R., & Kidd Jr., J. N. (2012). A survey of potential human-precursor robotic asteroid missions. Advances in the Astronautical Sciences, 142, 561-578.
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  Abstract: A preliminary mission analyses survey of conceptual robotic asteroid missions that are precursor to potential human asteroid missions is provided, yielding a set of parametric data that can be used for preliminary mission planning. For a set of carefully chosen asteroids, this study generated a table of delta-v data that extends over a range of launch opportunity dates and a range of total transfer times. A subjective comparison of missions was performed and the comparison results are reported, further evaluating the low delta-v analyses data based on a set of Key Performance Parameters that included Earth departure energy (C3) and total transfer time, as well as total delta-v. The key parameter comparison yielded a table of data that synthesizes the rather large set of mission analyses data into a set of "best" cases.
• Fink, W., Tuller, M., Jacobs, A., Kulkarni, R., Tarbell, M. A., Furfaro, R., & Baker, V. R. (2012). Robotic lake lander test bed for autonomous surface and subsurface exploration of Titan lakes. IEEE Aerospace Conference Proceedings.
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  Abstract: We introduce a robotic lake lander test bed that can be operated either stand-alone or as part of a Tier-Scalable Reconnaissance mission architecture to study and field test an integrated hardware and software framework for fully autonomous surface and subsurface exploration and navigation of liquid bodies. The lake lander is equipped with both surface and subsurface sensor technologies. Our particular focus is on Saturn's moon Titan with its hydrocarbon lakes with respect to future missions involving lake landers (e.g., Titan Mare Explorer (TiME) mission), potentially in conjunction with balloons/airships and orbiter-support overhead. This test bed serves as an analog to a Titan unpiloted surface vessel equipped with its own onboard realtime navigation and hazard avoidance system, surface and subsurface exploration sensor suite, and autonomous science investigation software system. As such the test bed helps map out a technical path toward true autonomy for the robotic exploration of the Solar System. © 2012 IEEE.
• Furfaro, R. (2012). An efficient multiproblem strategy for accurate solutions of linear particle transport problems in spherical geometry. Nuclear Science and Engineering.
• Furfaro, R. (2012). Autonomous real-time landing site selection for Venus and Titan using Evolutionary Fuzzy Cognitive Maps. Applied Soft Computing Journal.
• Furfaro, R. (2012). Derivation of a Physically Based Hybrid Technique for the Solution of Source-Driven Time-Dependent Linear Boltzmann Equations. Transport Theory and Statistical Physics.
• Furfaro, R. (2012). Modified energy cascade model adapted for a multicrop Lunar greenhouse prototype. Advances in Space Research.
• Furfaro, R. (2012). Neutron inverse kinetics via Gaussian Processes. Annals of Nuclear Energy.
• Furfaro, R. (2012). On Radiative Transfer in Dense Vegetation Canopies. Transport Theory and Statistical Physics.
• Furfaro, R. (2012). The Biological Oxidant and Life Detection (BOLD) mission: A proposal for a mission to Mars. Planetary and Space Science.
• Furfaro, R., & Wibben, D. R. (2012). Mars atmospheric entry guidance via multiple sliding surface guidance for reference trajectory tracking. AIAA/AAS Astrodynamics Specialist Conference 2012.
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  Abstract: To improve the accuracy of Mars landing, future missions will require robust, closed-loop guidance schemes for the entry portion of the atmospheric flight. A new nonlinear atmospheric entry guidance law for low lift landers has been developed. The Multiple Sliding Surface Guidance (MSSG) for tracking a reference trajectory is proposed. The guidance method is based on higher order sliding mode control theory adapted to the problem of entry guidance. The higher order sliding mode control has been adapted to account for the specific 2-sliding mode exhibited by the longitudinal motion of the entry vehicle, using bank angle control for following a reference trajectory. The global stability nature of the MSSG law is proven by using a Lyapunov-based approach and the performance is analyzed via a 3-DOF Monte Carlo simulation. © 2012 by the American Institute of Aeronautics and Astronautics.
• Furfaro, R., Cersosimo, D., & Bellerose, J. (2012). Close proximity asteroid operations using sliding control modes. Advances in the Astronautical Sciences, 143, 455-470.
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  Abstract: Due to their uncertain dynamical environment, close proximity operations around small celestial bodies are extremely challenging. In this paper, we show that the Multiple Sliding Surface Guidance (MSSG) algorithm, already proposed for autonomous asteroid pin-point guidance, can be extended to guide the transition of the spacecraft from any two desired states, including hovering, surface and orbital states. MSSG is based on Higher Order Sliding Mode (HOSM) control theory and takes advantage of the fact that the motion of the spacecraft around asteroids exists in a 2-sliding mode, i.e. The acceleration command appears at the second derivative of the defined sliding surface. The proposed algorithm is constructed by the proper concatenation of two sliding surfaces and takes advantage of the system's ability to reach the sliding surfaces in finite time. Importantly, the MSSG algorithm does not require either ground-based or on-board trajectory generation but computes an acceleration command that targets a specified state based on purely knowledge of the current and desired position and velocity. The classes of trajectories generated in this fashion are a function of the current and final states as well as of the guidance gains. Moreover, the controller is shown to be globally stable in the Lyapunov sense. MSSG is implemented in simulation scenarios comprising a variety of operations around a model asteroid, demonstrating the ability of the algorithm to guide the system between 1) two hovering states, 2) surface and hovering states and 3) surface to hovering. The MSSG algorithm is also shown to be able to shape the closed-loop trajectories to satisfy the requirements imposed by the need to execute a defined set of close-proximity operations.
• Furfaro, R., Cersosimo, D., & Wibben, D. R. (2012). Asteroid precision landing via Multiple Sliding Surfaces Guidance techniques. Advances in the Astronautical Sciences, 142, 3733-3752.
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  Abstract: Autonomous close proximity operations (hovering, landing) in the low-gravity environment exhibited by asteroids are particularly challenging. A novel nonlinear landing guidance scheme has been developed for spacecrafts that are required to execute autonomous closed-loop guidance to a designated point on the asteroid surface. Based on High Order Sliding Mode control theory, the proposed Multiple Sliding Surface Guidance (MSSG) algorithm has been designed to take advantage of the ability of the system to reach the sliding surface in a finite time. High control activity typical of sliding control design is avoided resulting in a guidance law that is robust against unmodeled yet bounded perturbations. The proposed MSSG does not require any off-line trajectory generation and therefore it is flexible enough to target a large variety of points on the surface without the need of ground-based trajectory analysis. The global stability of the proposed guidance algorithm is proven using a Lyapunov-based approach. The behavior of the MSSG-based class of asteroid landing trajectories is investigated via a parametric analysis and a full set of Monte Carlo simulations in realistic landing scenarios. Based on such results, the MSSG algorithm is demonstrated to be very accurate and flexible. The proposed scheme is suitable for onboard implementation and deployment for asteroid landing and close proximity operations.
• Furfaro, R., Fink, W., & Kargel, J. S. (2012). Autonomous real-time landing site selection for Venus and Titan using Evolutionary Fuzzy Cognitive Maps. Applied Soft Computing Journal, 12(12), 3825-3839.
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  Abstract: Future science-driven landing missions, conceived to collect in situ data on regions of planetary bodies that have the highest potential to yield important scientific discoveries, will require a higher degree of autonomy. The latter includes the ability of the spacecraft to autonomously select the landing site using real-time data acquired during the descent phase. This paper presents the development of an Evolutionary Fuzzy Cognitive Map (E-FCM) model that implements an artificial intelligence system capable of autonomously selecting a landing site with the highest potential for scientific discoveries constrained by the requirement of soft landing in a region with safe terrains. The proposed E-FCM evolves its internal states and interconnections as a function of real-time data collected during the descent phase, therefore improving the decision process as more accurate information becomes available. The E-FCM is constructed using knowledge accumulated by planetary experts and it is tested on scenarios that simulate the decision process during the descent phase toward the Hyndla Regio on Venus. The E-FCM is shown to quickly reach conclusions that are consistent with what would be the choice of a planetary expert if the scientist were presented with the same information. The proposed methodology is fast and efficient and may be suitable for on-board spacecraft implementation and real-time decision making during the course of robotic exploration of the Solar System. © 2012 Elsevier B.V. All rights reserved.
• Gaudet, B., & Furfaro, R. (2012). Adaptive pinpoint and fuel efficient Mars landing using Reinforcement Learning. Advances in the Astronautical Sciences, 143, 1309-1328.
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  Abstract: Future unconstrained and science-driven missions to Mars will require advanced guidance algorithms that are able to adapt to more demanding mission requirements, e.g. landing on selected locales with pinpoint accuracy while autonomously flying fuel-efficient trajectories. In this paper, we will present a novel guidance algorithm designed by applying the principles of Reinforcement Learning (RL) theory. The goal is to devise an adaptive guidance algorithm that enables robust, fuel efficient, and accurate landing without the need for off-line trajectory generation. Results from a Monte Carlo simulation campaign show that the algorithm is capable of autonomously flying trajectories that are close to the optimal minimum-fuel solutions with an accuracy that surpasses conventional Apollo-like guidance algorithms. The proposed RL-based guidance algorithm exhibits a high degree of flexibility and can easily accommodate autonomous retargeting while maintaining accuracy and fuel efficiency. Although reinforcement learning and other similar machine learning techniques have been previously applied to aerospace guidance and control problems (e.g., autonomous helicopter control), this appears, to the best of our knowledge, to be the first application of reinforcement learning to the problem of autonomous planetary landing.
• Gaudet, B., & Furfaro, R. (2012). Missile homing-phase guidance law design using reinforcement learning. AIAA Guidance, Navigation, and Control Conference 2012.
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  Abstract: A new approach to missile guidance law design is proposed, where reinforcement learning (RL) is used to learn a homing-phase guidance law that is optimal with respect to the missile's airframe dynamics as well as sensor and actuator noise and delays. It is demonstrated that this new approach results in a guidance law giving superior performance to either PN guidance or enhanced PN guidance laws developed using Lyapunov theory. Although optimal control theory can be used to derive an optimal control law under certain idealized modeling assumptions, we discuss how the RL approach gives more flexibility and higher expected performance for real-world systems. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Gaudet, B., & Furfaro, R. (2012). Robust spacecraft hovering near small bodies in environments with unknown dynamics using reinforcement learning. AIAA/AAS Astrodynamics Specialist Conference 2012.
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  Abstract: Autonomous close proximity operations (including hovering and landing) in the lowgravity environment exhibited by asteroids are particularly challenging. Current approaches to this problem require knowledge of the environmental dynamics in the asteroid's vicinity. This knowledge is costly, both in terms of time and money, to acquire. This paper uses reinforcement learning (RL) to develop a novel non-linear hovering controller with sufficient robustness to allow precision hovering in unknown environments, limited only by the maximum thrust requirements imposed by the environment. We demonstrate the robustness of the controller by simulating precision hovering in multiple environments that were unknown during the policy optimization. The environments are modeled using non-uniform rotation and a non-uniform gravity field. Simulations were also run using a shape model of the asteroid Itokawa. Performance is compared to that of an RL derived optimal linear PD controller and an LQR controller. Since the hovering controller requires an estimate of the spacecraft's state relative to a landmark on the asteroid's surface, we also introduce an optical seeker based navigation approach that accurately estimates the spacecraft's current state using only a single camera and laser range finder. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Giacomelli, G. A., Furfaro, R., Kacira, M., Patterson, L., Story, D., Boscheri, G., Lobascio, C., Sadler, P., Pirolli, M., Remiddi, R., Thangavelu, M., & Catalina, M. (2012). Bio-regenerative life support system development for Lunar/Mars habitats. 42nd International Conference on Environmental Systems 2012, ICES 2012.
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  Abstract: Bio-regenerative Life Support Systems (BLSS) uses biological processes to support an astronaut crew, and includes atmosphere revitalization, water recycling, food production, and organic waste recycling. The University of Arizona Controlled Environment Agriculture Center (UA-CEAC), Systems and Industrial Engineering Department, Sadler Machine Co. (USA) and Italian collaborators, Thales Alenia Space Italia (TAS-I), Aero-Sekur, SpA, and University of Naples Federico II are developing BLSS for future Lunar/Mars surface missions. Current efforts at UA-CEAC include operation of four BLSS Lunar Greenhouse (LGH) Prototype Units with the primary purpose of demonstrating poly-culture production of food crops in a semi-closed gaseous cycle, and preliminary efforts of waste DWE-Composting, Solar Concentrating Plant Lighting/Power System, and System Monitoring/Telepresence Support. TAS-I, the University of Naples, and Aero-Sekur BLSS efforts in Italy include operation of Recyclab, the EDEN chamber, and the development of space plant growth chambers. UA-CEAC efforts are supported by NASA Ralph Steckler Phase II Space Grant while the Italian collaborators have been supported by ESA, ASI, and regional, and internal sources. Based on NASA crop production area estimates the LGH with its four modules will support a four person crew with 100% of their water/atmosphere recycling, and 50%of their total daily dietary caloric intake, (~1000 kcal per person). The use of BLSS in conjunction with physicochemical life support systems offers redundant life support systems for increased crew safety and a healthy diet. Unique features of the LGH effort are its closed system approach, poly-culture production for a diverse vegetarian diet, efforts to close the water cycle, integration of composting into the water and air revitalization cycles, fiber-optic delivery of concentrated sunlight for crop production, and near real-time remote decision support capabilities. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Kacira, M., Giacomelli, G. A., Patterson, R. L., Furfaro, R., Sadler, P. D., Boscheri, G., Lobascio, C., Lamantea, M., Wheeler, R. M., & Rossignoli, S. (2012). System dynamics and performance factors of a lunar greenhouse prototype bioregenerative life support system. Acta Horticulturae, 952, 575-582.
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  Abstract: Future habitation of space, including lunar outposts will require special systems capable of performing important tasks such as revitalizing atmosphere (generate oxygen and fix carbon dioxide), purifying water (e.g., via plant transpiration), and growing human food. Bioregenerative Life Support Systems (BLSS) represent a solution to the problem of sustaining human existence in space. The lunar greenhouse (LGH) prototype project funded by NASA Steckler Phase I Space Grant supported collaboration from a multidisciplinary and multinational team to evaluate the scientific and technical merit and feasibility of a lunar greenhouse prototype for BLSS. The LGH system was constructed to be lightweight, collapsible for transport, autonomous for deployment, modular for expansion, with a hydroponic multi-cropping system that could produce NASA candidate crops such as lettuce, strawberry, sweet potato, and tomato. The system was instrumented to continuously monitor all primary resource inputs (feed water, nutrient solution, CO2, labor, and energy) as well as desired outputs (biomass, condensed water, oxygen generated). This paper reports results of a nine-month research with four repeated closure experiments on production outputs and resource inputs of the LGH system. The Phase I project concluded that the LGH system was capable of producing 2.26±0.33 kg day-1 biomass, 21.4±1.85 kg day -1 of condensed water, and consuming 0.07±0.11 kg day -1 fertilizer, 25.7±3.31 kg day-1 input water, 100.3 kWh day-1 (361.1 MJ day-1) as well as 35.9 min day-1 labor use.
• Kidd Jr., J. N., Furfaro, R., Wibben, D. R., Hergenrother, C. W., & Lauretta, D. (2012). Mission analysis for temporary geocentric asteroids. AIAA/AAS Astrodynamics Specialist Conference 2012.
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  Abstract: This paper presents a mission analysis study for manned missions to a special class of asteroids which have been captured in a temporary geocentric orbit, as demonstrated recently by the discovery of asteroid 2006 RH120. Possible trajectories to 2006 RH120 are surveyed using a preliminary global optimization tool based on differential evolution. The minimum ΔV trajectories found by our methodology show that temporary geocentric manned missions to 2006 RH120 can be as low as 3 km/sec if launched in 2028. Parametric studies show that feasible trajectories may have a total round trip between 150 and 210 days with a stay time between 10 and 20 days. A subset of the best preliminary trajectories are validated using a higher fidelity tool capable of modeling the gravitational influence of the more relevant bodies in the solar system. A brief and preliminary discussion on the options for mission architectures that implement the proposed class of trajectories is finally presented. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Picca, P., & Furfaro, R. (2012). Neutron inverse kinetics via Gaussian Processes. Annals of Nuclear Energy, 47, 146-154.
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  Abstract: The paper introduces the application of Gaussian Processes (GPs) to determine the subcriticality level in accelerator-driven systems (ADSs) through the interpretation of pulsed experiment data. ADSs have peculiar kinetic properties due to their special core design. For this reason, classical - inversion techniques based on point kinetic (PK) generally fail to generate an accurate estimate of reactor subcriticality. Similarly to Artificial Neural Networks (ANNs), Gaussian Processes can be successfully trained to learn the underlying inverse neutron kinetic model and, as such, they are not limited to the model choice. Importantly, GPs are strongly rooted into the Bayes' theorem which makes them a powerful tool for statistical inference. Here, GPs have been designed and trained on a set of kinetics models (e.g. point kinetics and multi-point kinetics) for homogeneous and heterogeneous settings. The results presented in the paper show that GPs are very efficient and accurate in predicting the reactivity for ADS-like systems. The variance computed via GPs may provide an indication on how to generate additional data as function of the desired accuracy. © 2012 Elsevier Ltd. All rights reserved.
• Schulze-Makuch, D., Head, J. N., Houtkooper, J. M., Knoblauch, M., Furfaro, R., Fink, W., Fairén, A. G., Vali, H., Sears, S. K., Daly, M., Deamer, D., Schmidt, H., Hawkins, A. R., Sun, H. J., Lim, D. S., Dohm, J., Irwin, L. N., Davila, A. F., Mendez, A., & Andersen, D. (2012). The Biological Oxidant and Life Detection (BOLD) mission: A proposal for a mission to Mars. Planetary and Space Science, 67(1), 57-69.
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  Abstract: The next step in the exploration of Mars should include a strong and comprehensive life detection component. We propose a mission called BOLD: Biological Oxidant and Life Detection mission. The scientific objectives of the BOLD mission are to characterize habitability of the martian surface and to search for evidence of extinct or extant life. In contrast to the Viking mission, which was designed to detect heterotrophic life on Mars, the BOLD mission incorporates a more comprehensive search for autotrophic microorganisms, as well as detecting a variety of biomarkers and understanding their environment. Six miniature landers are envisioned for BOLD that utilize either an orbital (e.g. Viking) or direct entry (e.g.; MER, Phoenix) mission architecture. The number of landers will provide mission redundancy, and each will incorporate a Mars Soil Analyzer, a Multispectral Microscopic Imager, a Nanopore-ARROW that detects biopolymers with single molecule resolution, an Atmospheric Structure and Surface Environment Instrument, a Fluorescent Stain experiment, and a Chirality experiment. A terrain navigation system, coupled with robust propulsion, permits a landing accuracy on the order of meters if required to meet the science objectives. The probes will use existing orbiters for communication relay if the orbiter architecture proves too ambitious. © 2012 Elsevier Ltd. All rights reserved.
• Selnick, S., Furfaro, R., & Wibben, D. R. (2012). Atmospheric entry guidance via multiple sliding surfaces control for Mars precision landing. Advances in the Astronautical Sciences, 142, 867-885.
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  Abstract: Improving Mars landing accuracy will require the implementation of robust, closed-loop guidance schemes for the entry portion of the atmospheric flight. A novel non-linear atmospheric entry guidance law has been developed for a class of low-lift landers similar to the one expected to be flown in the upcoming Mars Science Laboratory (MSL) mission. Here we proposed a Multiple Sliding Surface Guidance (MSSG) approach for Mars entry guidance. The presented guidance scheme is based on a higher order sliding mode control theory adapted to account for (1) the specific 2-sliding mode order exhibited by the longitudinal motion of the entry vehicle guided, using bank angle variations and (2) the ability of the system to reach the sliding surface in a finite time. Contrary to more standard methods designed to track a drag-based profile as a function of the range-to-go, the proposed scheme does not require any off-line trajectory generation and therefore it is suitable for real-time implementation. The global stability nature of the MSSG law is proven by using a Lyapunov-based approach. A parametric study has been conducted to understand the behavior of such class of trajectories as a function of the guidance parameters. The MSSG algorithm targeting ability is analyzed through a set of Monte Carlo simulations where the guidance law is required to operate under off-nominal conditions. Simulation results show good performance under perturbations and parameter uncertainties.
• Wibben, D. R., & Furfaro, R. (2012). Integrated guidance and attitude control for asteroid proximity operations using higher order sliding modes. AIAA/AAS Astrodynamics Specialist Conference 2012.
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  Abstract: An integrated guidance and attitude control scheme for asteroid proximity operations is presented. The development of this algorithm is motivated by the desire to implement robust and integrated spacecraft GNC schemes for asteroid close proximity operations. Autonomous maneuvering about small bodies is particularly challenging because of the uncertain, low-gravity environment. Based on Higher Order Sliding Mode (HOSM) control theory, the integrated Multiple Sliding Surface Guidance and Control (MSSGC) law has been designed to drive the system to the selected sliding surface in a finite time. The MSSGC scheme integrates the spacecraft's guidance and attitude control into a common framework that guides the 6-DOF spacecraft to a desired position about the asteroid with the desired orientation, all without the need for a pre-computed reference trajectory. A Lyapunov-based stability analysis shows that the system is globally stable against unmodeled dynamics and perturbations typically expected in small body environments. Results demonstrate that the algorithm is successful in driving the system to the desired target point (either landing on the surface or hovering above a desired location) with zero velocity and with the desired attitude and zero rotational rates. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Wibben, D. R., & Furfaro, R. (2012). Integrated guidance and attitude control for pinpoint lunar guidance using Higher Order Sliding Modes. Advances in the Astronautical Sciences, 143, 1369-1382.
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  Abstract: A novel non-linear guidance and attitude control scheme for pinpoint lunar landing is presented. The development of this algorithm is motivated by the desire to increase landing accuracy due to more stringent landing requirements in future lunar mission architectures and by the interest to integrate the attitude control and landing guidance into the same algorithm. Based on Higher Order Sliding Mode control theory, the proposed Multiple Sliding Surface Guidance and Control (MSSGC) algorithm has been designed to take advantage of the ability of the system to converge to the sliding surface in a finite time. The proposed MSSGC does not require the generation of a trajectory off-line and therefore it is very flexible without the need of off-line trajectory generation. The proposed guidance law is proven globally stable using a Lyapunov-based approach. Results from a set of parametric studies demonstrate that the MSSGC law not only drives the spacecraft to the desired position with zero velocity, but also with the desired attitude and angular rates.
• Alexis, J., Kargel, J. S., Tanaka, K. L., Crown, D. A., Berman, D. C., Fairén, A. G., Baker, V. R., Furfaro, R., Candelaria, P., & Sasaki, S. (2011). Secondary chaotic terrain formation in the higher outflow channels of southern circum-Chryse, Mars. Icarus, 213(1), 150-194.
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  Abstract: Higher outflow channel dissection in the martian region of southern circum-Chryse appears to have extended from the Late Hesperian to the Middle Amazonian Epoch. These outflow channels were excavated within the upper 1. km of the cryolithosphere, where no liquid water is expected to have existed during these geologic epochs. In accordance with previous work, our examination of outflow channel floor morphologies suggests the upper crust excavated by the studied outflow channels consisted of a thin (a few tens of meters) layer of dry geologic materials overlying an indurated zone that extends to the bases of the investigated outflow channels (1. km in depth). We find that the floors of these outflow channels contain widespread secondary chaotic terrains (i.e., chaotic terrains produced by the destruction of channel-floor materials). These chaotic terrains occur within the full range of outflow channel dissection and tend to form clusters. Our examination of the geology of these chaotic terrains suggests that their formation did not result in the generation of floods. Nevertheless, despite their much smaller dimensions, these chaotic terrains are comprised of the same basic morphologic elements (e.g., mesas, knobs, and smooth deposits within scarp-bound depressions) as those located in the initiation zones of the outflow channels, which suggests that their formation must have involved the release of ground volatiles. We propose that these chaotic terrains developed not catastrophically but gradually and during multiple episodes of nested surface collapse. In order to explain the formation of secondary chaotic terrains within zones of outflow channel dissection, we propose that the regional Martian cryolithosphere contained widespread lenses of volatiles in liquid form. In this model, channel floor collapse and secondary chaotic terrain formation would have taken place as a consequence of instabilities arising during their exhumation by outflow channel dissection. Within relatively warm upper crustal materials in volcanic settings, or within highly saline crustal materials where cryopegs developed, lenses of volatiles in liquid form within the cryolithosphere could have formed, and/or remained stable.In addition, our numerical simulations suggest that low thermal conductivity, dry fine-grained porous geologic materials just a few tens of meters in thickness (e.g., dunes, sand sheets, some types of regolith materials), could have produced high thermal anomalies resulting in subsurface melting. The existence of a global layer of dry geologic materials overlying the cryolithosphere would suggest that widespread lenses of fluids existed (and may still exist) at shallow depths wherever these materials are fine-grained and porous. The surface ages of the investigated outflow channels and chaotic terrains span a full 500 to 700. Myr. Chaotic terrains similar in dimensions and morphology to secondary chaotic terrains are not observed conspicuously throughout the surface of Mars, suggesting that intra-cryolithospheric fluid lenses may form relatively stable systems. The existence of widespread groundwater lenses at shallow depths of burial has tremendous implications for exobiological studies and future human exploration. We find that the clear geomorphologic anomaly that the chaotic terrains and outflow channels of southern Chryse form within the Martian landscape could have been a consequence of large-scale resurfacing resulting from anomalously extensive subsurface melt in this region of the planet produced by high concentrations of salts within the regional upper crust. Crater count statistics reveal that secondary chaotic terrains and the outflow channels within which they occur have overlapping ages, suggesting that the instabilities leading to their formation rapidly dissipated, perhaps as the thickness of the cryolithosphere was reset following the disruption of the upper crustal thermal structure produced during outflow channel excavation. © 2010 Elsevier Inc.
• Cupples, M. L., Furfaro, R., Hergenrother, C. W., Adebonojo Jr., B. O., Wibben, D. R., & Kidd Jr., J. N. (2011). A mission analysis survey of potential humanprecursor robotic asteroid missions. Advances in the Astronautical Sciences, 140, 3-20.
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  Abstract: A preliminary mission analyses survey for conceptual robotic asteroid missions that are precursor to potential human asteroid missions is provided, yielding a set of parametric data that can be used for preliminary mission planning. For a set of carefully chosen asteroids, this study generated a table of delta-v data that extends over a range of launch opportunity dates and a range of total transfer times. A subjective comparison of missions was performed and the comparison results are reported, further evaluating the low delta-v analyses data based on a set of Key Performance Parameters that included Earth departure energy (C3) and total transfer time, as well as total delta-v. The key parameter comparison yielded a table of data that synthesizes the rather large set of mission analyses data into a set of "best" cases. Each of the best cases is then superimposed on launch vehicle (LV) mass vs. C3 data that further extends the preliminary mission planning data into the LV and Earth departure energy domain. The mass vs. C3 data can aid in LV choice based on a known spacecraft mass and the preliminary mission analyses data.
• Dohm, J. M., Miyamoto, H., Ori, G. G., Fairén, A., Davila, A. F., Komatsu, G., Mahaney, W. C., Williams, J. -., Joye, S. B., Achille, G. D., Oehler, D. Z., Marzo, G. A., Schulze-Makuch, D., Acocella, V., Glamoclija, M., Pondrelli, M., Boston, P., Hart, K. M., Anderson, R. C., , Baker, V. R., et al. (2011). An inventory of potentially habitable environments on Mars: Geological and biological perspectives. Special Paper of the Geological Society of America, 483, 317-347.
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  Abstract: On Earth, biology, hydrology, and geology are interlinked such that certain types of life are often associated with specifi c conditions, including rock type, pressure, temperature, and chemistry. Life on Earth has established itself in diverse and extreme niches, presenting the possibility that Mars, too, may hold records of fossilized and/or extant life in diverse environments. Geologic, paleohydrologic, and climatic conditions through the evolution of Mars are similar in many respects to conditions occurring during the evolution of Earth and, as such, may point to environments on Mars with potential to have supported living systems. Here, we discuss examples of those Martian settings. Such extraterrestrial environments should be targeted by international robotic and/or manned missions to explore potential fossilized or extant life on Mars. © 2011 Geological Society of America.
• Furfaro, R. (2011). A hybrid transport point-kinetic method for simulating source transients in subcritical systems. Annals of Nuclear Energy.
• Furfaro, R. (2011). Secondary chaotic terrain formation in the higher outflow channels of southern circum-Chryse, Mars. Icarus.
• Furfaro, R. (2011). Solving radiative transfer problems in highly heterogeneous media via domain decomposition and convergence acceleration techniques. Applied Radiation and Isotopes.
• Furfaro, R., Kargel, J. S., & Fink, W. (2011). Autonomous real-time site selection for venus and titan landing using evolutionary fuzzy cognitive maps. Proceedings of the 2011 International Conference on Artificial Intelligence, ICAI 2011, 2, 691-697.
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  Abstract: Future science-driven landing missions, conceived to collect in-situ data on regions of planetary bodies that have the highest potential to yield important scientific discoveries, will require a higher degree of autonomy. The latter includes the ability of the spacecraft to autonomously select the landing site using real-time data acquired during the descent phase. This paper presents the development of an Evolutionary Fuzzy Cognitive Map (E-FCM) model that implements an artificial intelligence system capable of selecting a landing site with the highest potential for scientific discoveries constrained by the requirement of soft landing on a region with safe terrain. The proposed E-FCM evolves its internal states and interconnections as function of the external data collected during the descent, therefore improving the decision process as more accurate information is available. The E-FCM is constructed using knowledge accumulated by experts and it is tested on scenarios that simulate the decision-making process during the descent toward the Hyndla Regio on Venus. The E-FCM is shown to quickly reach conclusions that are consistent with what a planetary expert would decide if the scientist were presented, in real-time, with the same available information. The proposed methodology is fast and efficient and may be suitable for on-board spacecraft implementation and real-time decision-making during the course of any robotic exploration of the Solar System.
• Furfaro, R., Selnick, S., Cupples, M. L., & Cribb, M. W. (2011). Non-linear Sliding Guidance algorithms for precision lunar landing. Advances in the Astronautical Sciences, 140, 945-964.
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  Abstract: Two classes of non-linear guidance algorithms for lunar precision landing are presented. The development of such algorithms is motivated by the need of more stringent landing requirements imposed by future lunar mission architectures (e.g. the ability to land anywhere from a generic lunar orbit). The first class of guidance algorithms, called Optimal Sliding Guidance (OSG) laws, analytically determine the optimal acceleration command and augment it with a sliding mode to provide robustness against perturbations. The second class of guidance algorithms, called Multiple Sliding Surface Guidance (MSSG) laws, employs two interconnected sliding surfaces to track an on-board generated trajectory that drive the descending lander to the desired location at the desired velocity. For both guidance algorithms, which are proven to be globally stable, a set of Monte Carlo simulations have been executed to verify their performances. Both algorithms perform very well, i.e. they exhibit precision a with very low guidance residual errors on the desired target point above the lunar surface. Overall, MSSG shows slightly better performances with two drawbacks: 1) it needs more propellant mass and 2) it requires a higher frequency guidance loop (greater or equal than 100 Hz). The latter it imposes more challenging requirements on the design of the lander avionics system. Conversely, OSG tends to behave in a smoother fashion with excellent landing performance, lower guidance cycle frequency (10 Hz) and less propellant mass. Importantly, MSSG may be employed as real-time guidance scheme to track trajectory generated by more conventional, Apollo-like targeting algorithms.
• Sadler, P. D., Giacomelli, G., Patterson, R. L., Kacira, M., Furfaro, R., Lobascio, C., Boscheri, G., Lamantea, M., Grizzaffi, L., Rossignoli, S., Pirolli, M., & DePascale, S. (2011). Bio-regenerative life support systems for space surface applications. 41st International Conference on Environmental Systems 2011, ICES 2011.
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  Abstract: Bio-regenerative Life Support Systems (BLSS) is the application of biological based processes to support an astronaut crew in space, including atmosphere revitalization, water recycling, food production, and organic waste recycling. Future long term lunar/Mars surface missions will require a high degree of redundancy with dissimilar systems for crew safety. The use of BLSS in conjunction with physicochemical life support systems offers a dissimilar system redundancy with the ability to operate in concert with PC systems as required. The University of Arizona Controlled Environment Agriculture Center (UA-CEAC), UA-Systems and Industrial Engineering Department, Sadler Machine Company, Thales Alenia Space-Italia, Aero-Sekur, SpA, and University of Naples Federico II are teamed in a U.S.-Italian collaborative effort to develop BLSS for future space surface missions. Current efforts supported by NASA's Ralph Steckler Phase I Space Grant as described in this paper includes operation of one of four units of the UA-CEAC prototype Lunar Greenhouse (LGH), a closed system study for crop production, water recycling, atmosphere revitalization, and labor analysis. It targets NASA's estimated biomass production levels to support a single crew member with 100% of their water/atmosphere recycling, and 50% of the total food intake (~1000 kcal). Generally, earlier BLSS efforts generated crop production data based on mono-culture cropping. The LGH is capable of simultaneously growing a diverse number of cultivars (poly-culture) which better represents the proposed crew diet. Utilizing Poly-culture crop production will impact earlier BLSS models that are based on mono-culture crop production and the LGH Poly-culture results will build upon these earlier BLSS models and improve their overall accuracy. TAS-I efforts with support from Agenzia Spaziale Italiana (Italian Space Agency), includes operation of Recyclab advanced life support laboratory and implementation of the Modified Energy Cascade (MEC) plant growth model. The collaborative efforts of the Italian and U.S. teams ultimately will target the development of an advanced BLSS model for space surface mission planners to utilize in the establishment of a sustained presence on the lunar/Martian surface. © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Boscheri, G., Furfaro, R., Giacomelli, G., Grizzaffi, L., Kacira, M., Lamantea, M., Lobascio, C., Patterson, L., & Sadler, P. (2010). Evaluation of bio-regenerative life support systems in the frame of a concurrent international cooperation. 40th International Conference on Environmental Systems, ICES 2010.
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  Abstract: With concurrent interests on Bio-regenerative Life Support Systems (BLSS), Italian and USA industrial and academic institutions, including Thales Alenia Space Italia (TAS-I), the University of Arizona (UA) and the Sadler Machine Company have teamed in a collaboration effort. The collaboration has been providing personnel exchanges, sharing accumulated experiences and complementary competencies to establish synergies in the multi-disciplinary field of BLSS. The initial phase has linked aerospace engineering and system design competences together with other professional fields of plant sciences, controlled environment production systems, mathematical modeling and computational analysis. The overriding theme of our activities is the successful crop production, with effective resources utilization, such that sufficient edible biomass will be continuously provided to supply the desired percentage of the crew food calories from the system. The focus is mainly with crops targeted for space such as lettuce, sweet potato and tomato. Using available data and existing models, crop production studies have been designed and implemented to achieve production results within a semi-closed structure that will be useful for correlation studies, as well as for strengthening the experiences with an operational prototype BLSS. While the EDEN controlled plant growth chamber sited at TAS-I Recyclab has been operated to focus TAS-I engineers attention on the critical physical and biological aspects on a small scale demonstrator, the 22 m3 Lunar Greenhouse (LGH) Prototype, sited at the Controlled Environment Agriculture Center (CEAC) at the University of Arizona (UA), has been upgraded and prepared for 9- months of extensive utilization, supported by the NASA Steckler Space Grant (Phase 1, January - October 2010). Data will be evaluated within a TAS-I implemented model for the plant-life-support element, based on the NASA Modified Energy Cascade (MEC) Model for Crop Growth19,21. Testing is in progress and data acquisition, management, utilization and improvements of the models will be completed. The subsequent system simulations will be used for developing future designs of such facilities. This paper describes the collaboration, focusing on the available facilities improvement, the definition of the data gathering, storage and elaboration strategies, the discussion of the preliminary results achieved and the illustration of the forthcoming activities. © 2010 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Furfaro, R. (2010). Identification of cryovolcanism on Titan using fuzzy cognitive maps. Planetary and Space Science.
• Furfaro, R., Kargel, J. S., Lunine, J. I., Fink, W., & Bishop, M. P. (2010). Identification of cryovolcanism on Titan using fuzzy cognitive maps. Planetary and Space Science, 58(5), 761-779.
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  Abstract: Future planetary exploration of Titan will require higher degrees of on-board automation, including autonomous determination of sites where the probability of significant scientific findings is the highest. In this paper, a novel Artificial Intelligence (AI) method for the identification and interpretation of sites that yield the highest potential of cryovolcanic activity is presented. We introduce the theory of fuzzy cognitive maps (FCM) as a tool for the analysis of remotely collected data in planetary exploration. A cognitive model embedded in a fuzzy logic framework is constructed via the synergistic interaction of planetary scientists and AI experts. As an application example, we show how FCM can be employed to solve the challenging problem of recognizing cryovolcanism from Synthetic Aperture Radar (SAR) Cassini data. The fuzzy cognitive map is constructed using what is currently known about cryovolcanism on Titan and relies on geological mapping performed by planetary scientists to interpret different locales as cryovolcanic in nature. The system is not conceived to replace the human scientific interpretation, but to enhance the scientists' ability to deal with large amounts of data, and it is a first step in designing AI systems that will be able, in the future, to autonomously make decisions in situations where human analysis and interpretation is not readily available or could not be sufficiently timely. The proposed FCM is tested on Cassini radar data to show the effectiveness of the system in reaching conclusions put forward by human experts and published in the literature. Four tests are performed using the Ta SAR image (October 2004 fly-by). Two regions (i.e. Ganesa Macula and the lobate high backscattering region East of Ganesa) are interpreted by the designed FCM as exhibiting cryovolcanism in agreement with the initial interpretation of the regions by Stofan et al. (2006). Importantly, the proposed FCM is shown to be flexible and adaptive as new data and knowledge are acquired during the course of exploration. Subsequently, the FCM has been modified to include topographic information derived from SAR stereo data. With this additional information, the map concludes that Ganesa Macula is not a cryovolcanic region. In conclusion, the FCM methodology is shown to be a critical and powerful component of future autonomous robotic spacecraft (e.g., orbiter(s), balloon(s), surface/lake lander(s), rover(s)) that will be deployed for the exploration of Titan. © 2010 Elsevier Ltd. All rights reserved.
• Dohm, J. M., Baker, V. R., Boynton, W. V., Fairén, A. G., Ferris, J. C., Finch, M., Furfaro, R., Hare, T. M., Janes, D. M., Kargel, J. S., Karunatillake, S., Keller, J., Kerry, K., Kim, K. J., Komatsu, G., Mahaney, W. C., Schulze-Makuch, D., Marinangeli, L., Ori, G. G., , Ruiz, J., et al. (2009). GRS evidence and the possibility of paleooceans on Mars. Planetary and Space Science, 57(5-6), 664-684.
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  Abstract: The Gamma Ray Spectrometer (Mars Odyssey spacecraft) has revealed elemental distributions of potassium (K), thorium (Th), and iron (Fe) on Mars that require fractionation of K (and possibly Th and Fe) consistent with aqueous activity. This includes weathering, evolution of soils, and transport, sorting, and deposition, as well as with the location of first-order geomorphological demarcations identified as possible paleoocean boundaries. The element abundances occur in patterns consistent with weathering in situ and possible presence of relict or exhumed paleosols, deposition of weathered materials (salts and clastic minerals), and weathering/transport under neutral to acidic brines. The abundances are explained by hydrogeology consistent with the possibly overlapping alternatives of paleooceans and/or heterogeneous rock compositions from diverse provenances (e.g., differing igneous compositions). © 2008 Elsevier Ltd.
• Fairén, A. G., Schulze-Makuch, D., Rodríguez, A. P., Fink, W., Davila, A. F., Uceda, E. R., Furfaro, R., Amils, R., & McKay, C. P. (2009). Evidence for Amazonian acidic liquid water on Mars-A reinterpretation of MER mission results. Planetary and Space Science, 57(3), 276-287.
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  Abstract: The Mars Exploration Rover (MER) missions have confirmed aqueous activity on Mars. Here we review the analyses of the field-based MER data, and conclude that some weathering processes in Meridiani Planum and Gusev crater are better explained by late diagenetic water-rock interactions than by early diagenesis only. At Meridiani, the discovery of jarosite by MER-1 Opportunity indicates acidic aqueous activity, evaporation, and desiccation of rock materials. MER-based information, placed into the context of published data, point to local and limited aqueous activity during geologically recent times in Meridiani. Pre-Amazonian environmental changes (including important variations in the near-surface groundwater reservoirs, impact cratering, and global dust storms and other pervasive wind-related erosion) are too extreme for pulverulent jarosite to survive over extended time periods, and therefore we argue instead that jarosite deposits must have formed in a climatically more stable period. Any deposits of pre-existent concretionary jarosite surviving up to the Amazonian would not have reached completion in the highly saline and acidic brines occurring at Meridiani. MER-2 Spirit has also revealed evidence for local and limited Amazonian aqueous environmental conditions in Gusev crater, including chemical weathering leading to goethite and hematite precipitation, rock layering, and chemical enhancement of Cl, S, Br, and oxidized iron in rocks and soils. The estimated relative age of the impact crater materials in Gusev indicates that these processes have taken place during the last 2 billion years. We conclude that minor amounts of shallow acidic liquid water have been present on the surface of Mars at local scales during the Amazonian Period. © 2008 Elsevier Ltd.
• Furfaro, R. (2009). Estimating water and ice content on planetary soils using neutron measurements: A neural network approach. Radiation Effects and Defects in Solids.
• Furfaro, R. (2009). Evidence for Amazonian acidic liquid water on Mars-A reinterpretation of MER mission results. Planetary and Space Science.
• Furfaro, R. (2009). GRS evidence and the possibility of paleooceans on Mars. Planetary and Space Science.
• Furfaro, R. (2009). Modelling neutron transport in planetary media via analytical multigroup diffusion theory. Radiation Effects and Defects in Solids.
• Furfaro, R. (2009). Prototype BLSS lunar greenhouse. SAE Technical Papers.
• Sadler, P., Giacomelli, G., Furfaro, R., Patterson, R., & Kacira, M. (2009). Prototype BLSS lunar greenhouse. SAE Technical Papers.
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  Abstract: The Prototype BLSS Lunar Greenhouse currently in operation at the University of Arizona - Controlled Environment Agriculture Center in Tucson, Arizona is an Advanced Life Support technology demonstration for supporting a sustained human presence at the future lunar science outpost. The focus of the investigation is to demonstrate water recycling, air revitalization, and food production using NASA targeted crops within a semi-closed system utilizing a scaled prototype lunar greenhouse design. Copyright © 2009 SAE International.
• Fink, W., Datta, A., Dohm, J. M., Tarbell, M. A., Jobling, F. M., Furfaro, R., Kargel, J. S., Schulze-Makuch, D., & Baker, V. R. (2008). Automated global feature analyzer - A driver for tier-scalable reconnaissance. IEEE Aerospace Conference Proceedings.
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  Abstract: For the purposes of space flight, reconnaissance field geologists have trained to become astronauts. However, the initial forays to Mars and other planetary bodies have been done by purely robotic craft. Therefore, training and equipping a robotic craft with the sensory and cognitive capabilities of a field geologist to form a science craft is a necessary prerequisite. Numerous steps are necessary in order for a science craft to be able to map, analyze, and characterize a geologic field site, as well as effectively formulate working hypotheses. We report on the continued development of the integrated software system AGFA: Automated Global Feature Analyzer©, originated by Fink at Caltech and his collaborators in 2001. AGFA is an automatic and feature-driven target characterization system that operates in an imaged operational area, such as a geologic field site on a remote planetary surface. AGFA performs automated target identification and detection through segmentation, providing for feature extraction, classification, and prioritization within mapped or imaged operational areas at different length scales and resolutions, depending on the vantage point (e.g., spaceborne, airborne, or ground). AGFA extracts features such as target size, color, albedo, vesicularity, and angularity. Based on the extracted features, AGFA summarizes the mapped operational area numerically and flags targets of "interest", i.e., targets that exhibit sufficient anomaly within the feature space. AGFA enables automated science analysis aboard robotic spacecraft, and, embedded in tier-scalable reconnaissance mission architectures, is a driver of future intelligent and autonomous robotic planetary exploration. ©2008 IEEE.
• Furfaro, R. (2008). A statistical framework for the sensitivity analysis of radiative transfer models. IEEE Transactions on Geoscience and Remote Sensing.
• Furfaro, R. (2008). The search for life beyond Earth through fuzzy expert systems. Planetary and Space Science.
• Furfaro, R., Dohm, J. M., Fink, W., Kargel, J., Schulze-Makuch, D., Fairén, A., Palmero-Rodriguez, A., Baker, V. R., Ferré, P., Hare, T. M., Tarbell, M. A., Miyamoto, H., & Komatsu, G. (2008). The search for life beyond Earth through fuzzy expert systems. Planetary and Space Science, 56(3-4), 448-472.
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  Abstract: Autonomy will play a key role in future science-driven, tier-scalable robotic planetary reconnaissance to extremely challenging (by existing means), locales on Mars and elsewhere that have the potential to yield significant geological and possibly exobiologic information. The full-scale and optimal deployment of the agents employed by tier-scalable architectures requires the design, implementation, and integration of an intelligent reconnaissance system. Such a system should be designed to enable fully automated and comprehensive characterization of an operational area, as well as to integrate existing information with acquired, "in transit" spatial and temporal sensor data, to identify and home in on prime candidate locales. These may include locales with the greatest potential of containing life. Founded on the premise that water and energy are key to life, we have designed a fuzzy system that can (1) acquire the appropriate past/present water/energy indicators while the tier-scalable mission architecture is deployed (first layer), and (2) evaluate habitability through a specialized fuzzy knowledge-base of the water and energy information (second layer) acquired in (1). The system has been tested through hypothetical deployments at two hypothesized regions on Mars. The fuzzy-based expert's simulation results corroborate the same conclusions provided by the human expert, and thus highlight the system's potential capability to effectively and autonomously reason as an interdisciplinary scientist in the quest for life. While the approach is demonstrated for Mars, the methodology is general enough to be extended to other planetary bodies. It can be readily modified and updated as our interdisciplinary understanding of planetary environments improves. We believe this work represents a foundational step toward implementing higher-level intelligence in robotic, tier-scalable planetary reconnaissance within and beyond the solar system. © 2007 Elsevier Ltd. All rights reserved.
• Furfaro, R., Lunine, J. I., Elfes, A., & Reh, K. (2008). Wind-based navigation of a hot-air balloon on titan: A feasibility study. Proceedings of SPIE - The International Society for Optical Engineering, 6960.
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  Abstract: Current analysis of data streamed back to Earth by the Cassini spacecraft features Titan as one of the most exciting places in the solar system. NASA centers and universities around the US, as well as the European Space Agency, are studying the possibility of sending, as part of the next mission to this giant moon of Saturn, a hot-air balloon (Montgolfier-type) for further and more in-depth exploration. The basic idea would be to design a reliable, semi-autonomous, and yet cheap Montgolfier capable of using continuous flow of waste heat from a power source to lift the balloon and sustain its altitude in the Titan environment. In this paper we study the problem of locally navigating a hot-air balloon in the nitrogen-based Titan atmosphere. The basic idea is to define a strategy (i.e. design of a suitable guidance system) that allows autonomous and semiautonomous navigation of the balloon using the available (and partial) knowledge of the wind structure blowing on the saturnian satellite surface. Starting from first principles we determined the appropriate thermal and dynamical models describing (a) the vertical dynamics of the balloon and (b) the dynamics of the balloon moving on a vertical plane (2-D motion). Next, various non-linear fuzzy-based control strategies have been evaluated, analyzed and implemented in MATLAB to numerically simulate the capability of the system to simultaneously maintain altitude, as well as a scientifically desirable trajectory. We also looked at the ability of the balloon to perform station keeping. The results of the simulation are encouraging and show the effectiveness of such a system to cheaply and effectively perform semi-autonomous exploration of Titan.
• Furfaro, R., Lunine, J. I., Kargel, J. S., & Fink, W. (2008). Intelligent systems for the autonomous exploration of titan and enceladus. Proceedings of SPIE - The International Society for Optical Engineering, 6960.
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  Abstract: Future planetary exploration of the outer satellites of the Solar System will require higher levels of onboard automation, including autonomous determination of sites where the probability of significant scientific findings is highest. Generally, the level of needed automation is heavily influenced by the distance between Earth and the robotic explorer(s) (e.g. spacecraft(s), rover(s), and balloon(s)). Therefore, planning missions to the outer satellites mandates the analysis, design and integration within the mission architecture of semiand/or completely autonomous intelligence systems. Such systems should (1) include software packages that enable fully automated and comprehensive identification, characterization, and quantification of feature information within an operational region with subsequent target prioritization and selection for close-up reexamination; and (2) integrate existing information with acquired, "in transit" spatial and temporal sensor data to automatically perform intelligent planetary reconnaissance, which includes identification of sites with the highest potential to yield significant geological and astrobiological information. In this paper we review and compare some of the available Artificial Intelligence (AI) schemes and their adaptation to the problem of designing expert systems for onboard-based, autonomous science to be performed in the course of outer satellites exploration. More specifically, the fuzzy-logic framework proposed is analyzed in some details to show the effectiveness of such a scheme when applied to the problem of designing expert systems capable of identifying and further exploring regions on Titan and/or Enceladus that have the highest potential to yield evidence for past or present life. Based on available information (e.g., Cassini data), the current knowledge and understanding of Titan and Enceladus environments is evaluated to define a path for the design of a fuzzy-based system capable of reasoning over collected data and capable of providing the inference required to autonomously optimize future outer satellites explorations.
• Kargel, J. S., Fink, W., Furfaro, R., & Miyamoto, H. (2008). Robotic resource exploration is a key to human expansion through the cosmos. Proceedings of SPIE - The International Society for Optical Engineering, 6960.
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  Abstract: If the goal of planetary exploration is to build a permanent and expanding, self-sustaining extraterrestrial civilization, then clever and myriad uses must be made of planetary resources. Resources must be identified and evaluated according to their practicality. A new economy should be devised based on resource occurrence, ore accessibility, options for ore transport, material beneficiation, and manufacturing; end uses and demand; and full economic cost/benefit assessment. Locating and evaluating these resources should be done with coordinated robotic assets arrayed in orbit and on the surface. Sensor arrays and tandem on-ground means of physical manipulation of rocks should incorporate highly capable onboard data processing, feature detection, and quantification of material properties; intelligent decision making; a flexible capacity to re-order priorities and act on those priorities in carrying out exploration programs; and human-robot interaction. As resource exploration moves into exploitation, sensors working in tandem with robust physical manipulation will place increased emphasis on automation in effective and safe robotic quarrying, tunneling, boring, and ore beneficiation. Any new global planetary economy will have to weigh the efficiency of resource identification and utilization with full-spectrum cost/benefit assessment for human health and safety, the environment, future habitability and sustainability, and human priorities in the development and growth of civilization. It makes no sense to rove from one planet to another in a wave of resource use and depletion, like interplanetary locusts. Robotic systems will open new worlds to human use, but they will also place a premium on human ability to control exponentially growing consumption.
• Miyamoto, H., Kargel, J. S., Fink, W., & Furfaro, R. (2008). Granular processes on Itokawa, a small near-Earth asteroid: Implications for resource utilization. Proceedings of SPIE - The International Society for Optical Engineering, 6960.
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  Abstract: Crucial questions for possible utilization of Near Earth Asteroids include how to break asteroid materials down to particle sizes that can be processed. This remained difficult to answer because of the limited number and resolutions of images previous obtained through asteroid missions. Recently, the Hayabusa spacecraft obtained unprecedentedly high-resolution images of a ∼300m-sized asteroid, Itokawa, which gives unique opportunity to discuss the nature of surface materials on a small asteroid. Hayabusa reveals that the asteroid is covered by fine- and coarse-grained materials, including granules, pebbles, cobbles, and boulders up to tens of meters. Gravels on this small asteroid appear to be loosely deposited along the gravitational equipotential surfaces. The existence of smooth areas as well as boulder-rich rough areas indicate that gravels should have experienced migrations and segregations. Thus, the issue regarding the breaking of asteroid materials appears to have been resolved naturally, at least for this asteroid, which has important implications for future robotic missions dedicated to resource exploration and utilization.
• Sadler, P., Furfaro, R., Giacomelli, G., & Patterson, L. (2008). Prototype BLSS lunar habitat. SAE Technical Papers.
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  Abstract: This paper describes a conceptual design for a prototype Bioregenerative Life Support System (BLSS) based Lunar Habitat. The overall goal of this study is to support a crew of four astronauts continually occupying the Lunar Habitat at the rim of Shackelton's Crater with 6 month re-supply and crew change-out interval. Currently under construction are four prototype Lunar Greenhouse Modules and a fifth prototype Post Harvest Module for recycling crew waste, water, and atmosphere based on this design. The proposed BLSS is highly integrated with the entire habitat and it is shown to dictate the development and design of the proposed lunar habitat prototype. Copyright © 2008 SAE International.
• Fink, W., Dohm, J. M., Tarbell, M. A., Hare, T. M., Baker, V. R., Schulze-Makuch, D., Furfaro, R., Fairén, A. G., P., T., Miyamoto, H., Komatsu, G., & Mahaney, W. C. (2007). Tier-scalable reconnaissance missions for the autonomous exploration of planetary bodies. IEEE Aerospace Conference Proceedings.
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  Abstract: A fundamentally new (scientific) reconnaissance mission concept, termed tier-scalable reconnaissance, for remote planetary (including Earth) atmospheric, surface and subsurface exploration recently has been devised [1-5] that soon will replace the engineering and safety constrained mission designs of the past, allowing for optimal acquisition of geologic, paleohydrologic, paleoclimatic, and possible astrobiologic information of Venus, Mars, Europa, Ganymede, Titan, Enceladus, Triton, and other extraterrestrial targets [6, 7]. This paradigm is equally applicable to potentially hazardous or inaccessible operational areas on Earth such as those related to military or terrorist activities, or areas that have been exposed to biochemical agents, radiation, or natural disasters. Traditional missions have performed local, ground-level reconnaissance through rovers and immobile landers, or global mapping performed by an orbiter. The former is safety and engineering constrained, affording limited detailed reconnaissance of a single site at the expense of a regional understanding, while the latter returns immense datasets, often overlooking detailed information of local and regional significance. © 2007 IEEE.
• Furfaro, R. (2007). Martian hydrogeology sustained by thermally insulating gas and salt hydrates. Geology.
• Furfaro, R. (2007). Neural network algorithm for coffee ripeness evaluation using airborne images. Applied Engineering in Agriculture.
• Furfaro, R. (2007). Spectral theory for photon transport in dense vegetation media: Caseology for the Canopy equation. Transport Theory and Statistical Physics.
• Kargel, J. S., Furfaro, R., Prieto-Ballesteros, O., Alexis, J., Montgomery, D. R., Gillespie, A. R., Marion, G. M., & Wood, S. E. (2007). Martian hydrogeology sustained by thermally insulating gas and salt hydrates. Geology, 35(11), 975-978.
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  Abstract: Numerical simulations and geologic studies suggest that high thermal anomalies beneath, within, and above thermally insulating layers of buried hydrated salts and gas hydrates could have triggered and sustained hydrologic processes on Mars, producing or modifying chaotic terrains, debris flows, gullies, and ice-creep features. These simulations and geologic examples suggest that thick hydrate deposits may sustain such geothermal anomalies, shallow groundwater tables, and hydrogeologic activity for eons. The proposed mechanism may operate and be self-reinforcing even in today's cold Martian climate without elevated heat flux. © 2007 The Geological Society of America.
• Schulze-Makuch, D., Houtkooper, J. M., Knoblauch, M., Furfaro, R., Fink, W., Fairén, A. G., Vali, H., Head, J. N., S., D., Dohm, J., Irwin, L. N., Daly, M., & Andersen, D. (2007). The Biological Oxidant and Life Detection (BOLD) Mission: An outline for a new mission to Mars. Proceedings of SPIE - The International Society for Optical Engineering, 6694.
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  Abstract: The Viking mission was the only mission to date that conducted life detection experiments. It revealed ambiguous and still controversial results. New findings and hypotheses urge a re-evaluation of the Viking results and a re-evaluation of the evidence for the possible presence of life on Mars in general. Recent findings of abundant water ice on Mars, the presence of liquid contemporary water on the Martian surface, and the detection of methane in the Martian atmosphere further support this possibility. Current missions to be launched focus on habitability considerations (e.g., NASA Phoenix, NASA Mars Science Laboratory), but shy away from directly testing for life on Mars, with the potential exception of the ESA ExoMars mission. If these currently planned missions collect positive evidence toward habitability and the possible existence of extraterrestrial (microbial) life on Mars, it would be timely to propose a new mission to Mars with a strong life detection component. We propose such a mission called BOLD: Biological Oxidant and Life Detection Mission. The BOLD mission objective would be to quantify the amount of hydrogen peroxide existing in the Martian soil and to test for processes typically associated with life. Six landing packages are projected to land on Mars that include a limited power supply, a set of oxidant and life detection experiments, and a transmitter, which is able to transmit information via an existing Mars orbiter back to Earth.
• Furfaro, R., Dohm, J. M., & Fink, W. (2006). Fuzzy logic expert system for tier-scalable planetary reconnaissance. SpaceOps 2006 Conference.
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  Abstract: Future unconstrained, science-driven, smart planetary reconnaissance will require higher levels of onboard automation, including autonomous determination of sites where the probability of significant scientific findings is highest. In this paper, we describe the design of an expert system that, when embedded in a tier-scalable mission architecture deployed to collect information at multiple scales and using multiple instruments, is capable of autonomously performing synthesis of spatial, "in-transit" collected information to optimally home in on locales for further exploration. More specifically, the fuzzy logic framework has been used to design a system capable of "following-the-water", i.e. ingesting the appropriate water indicators to autonomously evaluate/assess the potential exhibited by the observed locale to host past and/or extant water. The system relies on a set of IF-THEN rules extracted to mimick the investigative approach of a planetary geologist/hydrologist. The system is simulated on hypothesized martian scenarios to show the potential of the overall approach. © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
• Furfaro, R. (2004). Radiative transfer theory in dense plant canopies: A neural network application to coffee cherry ripeness estimation, invited. Transactions of the American Nuclear Society, 90, 295-298.

Proceedings Publications

• Furfaro, R. (2020). A Guidance Law for Terminal Phase Exo-Atmospheric Interception Against a Maneuvering Target using Angle-Only Measurements Optimized using Reinforcement Meta-Learning. In AIAA Scitech 2020 Forum.
• Furfaro, R. (2020). Image-based Deep Reinforcement Learning for Autonomous Lunar Landing. In AIAA Scitech 2020 Forum.
• Furfaro, R. (2019). Actor-critic reinforcement learning approach to relative motion guidance in near-rectilinear orbit. In Advances in the Astronautical Sciences.
• Furfaro, R. (2019). Modeling imaging uncertainty for OSIRIS-REx’s asteroid approach observations. In Advances in the Astronautical Sciences.
• Furfaro, R. (2018). Application of ZEM/ZEV guidance for closed-loop transfer in the earth-moon system. In Space Flight Mechanics Meeting, 2018.
• Furfaro, R. (2018). Computational guidance for Mars entry and power descent. In Advances in the Astronautical Sciences.
• Furfaro, R. (2018). Deep learning for autonomous lunar landing. In Advances in the Astronautical Sciences.
• Furfaro, R. (2018). Human exploration of the Moon, Near-Earth Asteroids, and Mars using staging from Earth-Moon L-2 orbits and phasing orbit rendezvous. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R. (2018). Integrated guidance and control for pinpoint mars landing using reinforcement learning. In Advances in the Astronautical Sciences.
• Furfaro, R. (2018). LUMIO: Characterizing lunar meteoroid impacts with a CubeSat. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R. (2018). Lumio: Achieving autonomous operations for lunar exploration with a cubesat. In 15th International Conference on Space Operations, 2018.
• Furfaro, R. (2018). Smart camera system on-board a CubeSat for space-based object reentry and tracking. In 2018 IEEE/ION Position, Location and Navigation Symposium, PLANS 2018 - Proceedings.
• Furfaro, R. (2018). Theory of connections applied to first-order system of ordinary differential equations subject to component constraints. In Advances in the Astronautical Sciences.
• Furfaro, R. (2018). Uncertainty quantification for mars atmospheric entry using modified generalized polynomial chaos. In Advances in the Astronautical Sciences.
• Furfaro, R. (2018). Waypoint-based ZEM/ZEV feedback guidance: Applications to low-thrust interplanetary transfer and orbit raising. In Advances in the Astronautical Sciences.
• Furfaro, R. (2018). Waypoint-optimized closed-loop guidance for spacecraft rendezvous in relative motion. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2018). Integrated guidance for mars entry and powered descent using reinforcement learning and gauss pseudospectral method. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2018). Least-squares solution of a class of optimal space guidance problems via theory of connections. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2018). Maneuvering detection and prediction using inverse reinforcement learning for space situational awareness. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2018). Spacecraft rendezvous guidance in cluttered environments via artificial potential functions and reinforcement learning. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2018). System design of LUMIO: A CubeSat at Earth-Moon L2 for observing lunar meteoroid impacts. In Proceedings of the International Astronautical Congress, IAC.
• Maadani, M., Rosengren, A. J., Furfaro, R., & Amato, D. (2018, September). Attitude propagation of resident space objects with recurrent neural networks. In Advanced Maui Optical and Space Surveillance Technologies Conference.
• Campbell, T., Furfaro, R., Linares, R., & Gaylor, D. (2017, February). A Deep Learning Approach for Optical Autonomous Planetary Relative Terrain Navigation. In 27th AAS/AIAA Space Flight Mechanics Meeting.
• Furfaro, R. (2017). A deep learning approach for optical autonomous planetary relative terrain navigation. In Advances in the Astronautical Sciences.
• Furfaro, R. (2017). Modelling irregular small bodies gravity field via extreme learning machines. In Advances in the Astronautical Sciences.
• Furfaro, R. (2017). Policy gradient approach for dynamic sensor tasking applied to space situational awareness. In Advances in the Astronautical Sciences.
• Furfaro, R. (2017). Waypoint-Based generalized ZEM/ZEV feedback guidance for planetary landing via a reinforcement learning approach. In Advances in the Astronautical Sciences.
• Furfaro, R. (2016). Analysis and performance evaluation of ZEM/ZEV guidance and its sliding robustification for autonomous rendezvous in relative motion. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R. (2016). Mapping sensors measurements to resident space objects energy and state parameters space via extreme learning machines. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R. (2016). Mars-lunar greenhouse (M-LGH) prototype for bioregenerative life support systems in future planetary outposts. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R. (2016). Optimal Sliding Guidance for Earth-Moon Halo orbit station-keeping and transfer. In Advances in the Astronautical Sciences.
• Furfaro, R. (2016). Space Object classification using deep Convolutional Neural Networks. In FUSION 2016 - 19th International Conference on Information Fusion, Proceedings.
• Furfaro, R. (2016, Fall). Mars-Lunar Greenhouse (M-LGH) Prototype For Bioregenerative Life Support Systems in Future Planetary Outposts. In 67th International Astronautical Conference, Guadalajara, Mexico..
• Furfaro, R., Furfaro, R., & Furfaro, R. (2016). Relative optical navigation around small bodies via extreme learning machines. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2016). Robustification of a class of guidance algorithms for planetary landing: Theory and applications. In Advances in the Astronautical Sciences.
• Furfaro, R., Linares, R., Gaylor, D., & Jah, M. (2016). Mapping Sensors Measurements to the Resident Space Objects Behavior Energy and State Parameters Space via Extreme Learning Machines. In 67th International Astronautical Conference, Guadalajara, Mexico.
• Furfaro, R., Linares, R., Gaylor, D., Jah, M. K., & Walls, R. (2016, September). Resident Space Objects Characterization and Behavior Understanding via Machine Learning and Ontology-based Bayesian Networks. In Advanced Maui Optical and Space Surveillance Technologies Conference.
• Furfaro, R., Linares, R., Gaylor, D., Jah, M., & Walls, R. (2016). Resident Space Object Characterization and Behavior Understanding via Machine Learning and Ontology-based Bayesian Networks. In The Advanced Maui Optical and Space Surveillance Technologies Conference.
• Furfaro, R., Linares, R., Jah, M. K., & Gaylor, D. (2016, September). Mapping Sensors Measurements to the Resident Space Objects Behavior Energy and State Parameters Space via Extreme Learning Machines. In 67th International Astronautical Congress.
• Hart, M., Furfaro, R., Weiner, B. J., Corral, E. L., Lyons, E. H., Surdeanu, M., Butcher, E., Gaylor, D., Jah, M. K., Merchant, N. C., Ten Eyck, B., Walls, R., Walls, R., Ten Eyck, B., Merchant, N. C., Jah, M. K., Gaylor, D., Butcher, E., Surdeanu, M., , Lyons, E. H., et al. (2016, May). A New Approach to Space Domain Awareness at the University of Arizona. In NATO Symposium on Considerations for Space and Space-Enabled Capabilities in NATO Coalition Operations, SCI-283.
• Hart, M., Jah, M. K., Gaylor, D., Butcher, E., Ten Eyck, B., Corral, E. L., Furfaro, R., Lyons, E. H., Merchant, N. C., Surdeanu, M., Walls, R., Weiner, B. J., Hart, M., Jah, M. K., Gaylor, D., Butcher, E., Ten Eyck, B., Corral, E. L., Furfaro, R., , Lyons, E. H., et al. (2016, May). A New Approach to Space Domain Awareness at the University of Arizona. In NATO Symposium on "Considerations for Space and Space-Enabled Capabilities in NATO Coalition Operations".
• Linares, R., & Furfaro, R. (2016). Dynamic Sensor Tasking for Space Situational Awareness via Reinforcement Learning. In Advanced Maui Optical and Space Surveillance Technologies Conference.
• Linares, R., & Furfaro, R. (2016). Space Object classification using deep Convolutional Neural Networks. In Information Fusion (FUSION), 2016 19th International Conference on.
• Walls, R., Gaylor, D., Reddy Kanupuru, V. V., Furfaro, R., & Jah, M. K. (2016, September). Assessing the UN IADC Space Debris Mitigation Guidelines: A Case for Ontology-based Data Management. In Advanced Maui Optical and Space Surveillance Technologies Conference.
• Giacomelli, G. A., Kacira, M., Furfaro, R., Patterson, L., & Sadler, P. (2014, 08/2014). Plant production, energy balance and monitoring-control-telepresence in a recirculating hydroponic vegetable crop production system: prototype lunar greenhouse. In International Symposium on Innovation and New Technologies in Protected Cropping, 53-60.
• Giacomelli, G. A., Kacira, M., Furfaro, R., Patterson, L., & Sadler, P. (2015, November). Plant production, energy balance and monitoring-control-telepresence in a recirculating hydroponic vegetable crop production system: prototype lunar greenhouse. In International Symposium on Innovation and New Technologies in Protected Cropping, 1107, 53-60.
• Furfaro, R. (2014). A navigation scheme for pinpoint mars landing using radar altimetry, a digital terrain model, and a particle filter. In Advances in the Astronautical Sciences.
• Furfaro, R. (2014). Halo orbit targeting guidance via higher order sliding techniques. In Advances in the Astronautical Sciences.
• Furfaro, R. (2014). Interplanetary human exploration enabled by lunar swingbys and libration-point orbits. In AIAA/AAS Astrodynamics Specialist Conference 2014.
• Furfaro, R. (2014). Model-based systems engineering approach for the development of the science processing and operations center of the NASA OSIRIS-REx asteroid sample return mission. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R. (2014). Monitoring Earth's northern forests from spacecraft in Molniya orbits. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R. (2014). Near optimal feedback guidance design and the planar restricted three-body problem. In Advances in the Astronautical Sciences.
• Furfaro, R. (2014). Neural-based trajectory shaping approach for terminal planetary pinpoint guidance. In Advances in the Astronautical Sciences.
• Furfaro, R. (2014). Using lunar swingbys and libration-point orbits to extend human exploration to Mars. In Advances in the Astronautical Sciences.
• Furfaro, R., & Furfaro, R. (2014). Orbit control and hovering in asteroid dynamical enviroments using Higher Order Sliding Control theory. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2014). Attitude estimation via LIDAR altimetry and a particle filter. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2014). Non-linear pulsed guidance for asteroid close-proximity operations. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2014). Real-time state estimation for asteroid close-proximity operations via lidar altimetry and a particle filter. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2014). Some options for lunar exploration utilizing the Earth-Moon L2 libration point. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2014). The 2014 Earth return of the ISEE-3/ICE spacecraft. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2014). ZEM/ZEV sliding guidance for asteroid close-proximity orbital transfer and rendezvous. In Advances in the Astronautical Sciences.
• Furfaro, R. (2013). Application of convergence acceleration to the reactor kinetic equations: A comparative study. In International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2013.
• Furfaro, R. (2013). Development of non-linear guidance algorithms for asteroids close-proximity operations. In AIAA Guidance, Navigation, and Control (GNC) Conference.
• Furfaro, R. (2013). Estimation of asteroid model parameters using particle filters. In Advances in the Astronautical Sciences.
• Furfaro, R. (2013). Multiple Sliding Surface Guidance applied at binary asteroid systems. In Advances in the Astronautical Sciences.
• Furfaro, R. (2013). Using lunar swingbys and libration-point orbits to extend human exploration to interplanetary destinations. In Proceedings of the International Astronautical Congress, IAC.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2013). Multiple sliding surface guidance for planetary landing: Tuning and optimization via reinforcement learning. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2013). Optimal lunar landing and retargeting using a hybrid control strategy. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2013). Sliding guidance techniques for close proximity operations at multiple asteroid systems. In AIAA Guidance, Navigation, and Control (GNC) Conference.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2013). ZEM/ZEV guidance approach for asteroid touch-and-go sample collection maneuvers. In Advances in the Astronautical Sciences.
• Furfaro, R. (2012). A survey of potential human-precursor robotic asteroid missions. In Advances in the Astronautical Sciences.
• Furfaro, R. (2012). Adaptive pinpoint and fuel efficient Mars landing using Reinforcement Learning. In Advances in the Astronautical Sciences.
• Furfaro, R. (2012). Atmospheric entry guidance via multiple sliding surfaces control for Mars precision landing. In Advances in the Astronautical Sciences.
• Furfaro, R. (2012). Bio-regenerative life support system development for Lunar/Mars habitats. In 42nd International Conference on Environmental Systems 2012, ICES 2012.
• Furfaro, R. (2012). Close proximity asteroid operations using sliding control modes. In Advances in the Astronautical Sciences.
• Furfaro, R. (2012). Integrated guidance and attitude control for asteroid proximity operations using higher order sliding modes. In AIAA/AAS Astrodynamics Specialist Conference 2012.
• Furfaro, R. (2012). Mars atmospheric entry guidance via multiple sliding surface guidance for reference trajectory tracking. In AIAA/AAS Astrodynamics Specialist Conference 2012.
• Furfaro, R. (2012). Missile homing-phase guidance law design using reinforcement learning. In AIAA Guidance, Navigation, and Control Conference 2012.
• Furfaro, R. (2012). Mission analysis for temporary geocentric asteroids. In AIAA/AAS Astrodynamics Specialist Conference 2012.
• Furfaro, R. (2012). Robotic lake lander test bed for autonomous surface and subsurface exploration of Titan lakes. In IEEE Aerospace Conference Proceedings.
• Furfaro, R. (2012). Robust spacecraft hovering near small bodies in environments with unknown dynamics using reinforcement learning. In AIAA/AAS Astrodynamics Specialist Conference 2012.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2012). Asteroid precision landing via Multiple Sliding Surfaces Guidance techniques. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2012). Integrated guidance and attitude control for pinpoint lunar guidance using Higher Order Sliding Modes. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2012). Launch analyses supporting conceptual human-precursor robotic asteroid missions. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2012). Switching system model for pinpoint lunar landing guidance using a hybrid control strategy. In AIAA Guidance, Navigation, and Control Conference 2012.
• Furfaro, R. (2011). Autonomous real-time site selection for venus and titan landing using evolutionary fuzzy cognitive maps. In Proceedings of the 2011 International Conference on Artificial Intelligence, ICAI 2011.
• Furfaro, R. (2011). Bio-regenerative life support systems for space surface applications. In 41st International Conference on Environmental Systems 2011, ICES 2011.
• Furfaro, R. (2011). Non-linear Sliding Guidance algorithms for precision lunar landing. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2011). A mission analysis survey of potential humanprecursor robotic asteroid missions. In Advances in the Astronautical Sciences.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2011). Robotic test bed for autonomous surface exploration of Titan, Mars, and other planetary bodies. In IEEE Aerospace Conference Proceedings.
• Furfaro, R. (2010). A hybrid transport-point kinetic method for the analysis of source transients in subcritical systems. In International Conference on the Physics of Reactors 2010, PHYSOR 2010.
• Furfaro, R. (2010). Application of artificial neural networks to infer subcriticality level through kinetic models. In International Conference on the Physics of Reactors 2010, PHYSOR 2010.
• Furfaro, R. (2010). Convergence acceleration for multipanel fine group finite difference numerical benchmarks. In Transactions of the American Nuclear Society.
• Furfaro, R. (2010). Evaluation of bio-regenerative life support systems in the frame of a concurrent international cooperation. In 40th International Conference on Environmental Systems, ICES 2010.
• Furfaro, R., Furfaro, R., & Furfaro, R. (2010). Paneling strategy for ultra-fine group slowing down numerical benchmarks. In Transactions of the American Nuclear Society.
• Furfaro, R. (2009). Subcriticality determination by neural-based inversion of space-energy neutron kinetic equations. In American Nuclear Society - International Conference on Mathematics, Computational Methods and Reactor Physics 2009, M and C 2009.
• Furfaro, R. (2009). Time-dependent neutral particle transport in spherical geometry. In Transactions of the American Nuclear Society.
• Furfaro, R. (2008). Accelerated quasi-static method for neutron kinetics. In Transactions of the American Nuclear Society.
• Furfaro, R. (2008). Applications of convergence acceleration to particle transport in spherical geometry. In International Conference on the Physics of Reactors 2008, PHYSOR 08.
• Furfaro, R. (2008). Automated global feature analyzer - A driver for tier-scalable reconnaissance. In IEEE Aerospace Conference Proceedings.
• Furfaro, R. (2008). Forward and inverse models for photon transport in soil-ice mixtures and their application to the problem of retrieving optical properties of planetary surfaces. In Proceedings of SPIE - The International Society for Optical Engineering.
• Furfaro, R. (2008). Granular processes on Itokawa, a small near-Earth asteroid: Implications for resource utilization. In Proceedings of SPIE - The International Society for Optical Engineering.
• Furfaro, R. (2008). Intelligent systems for the autonomous exploration of titan and enceladus. In Proceedings of SPIE - The International Society for Optical Engineering.
• Furfaro, R. (2008). Inverse point kinetics with neural networks. In Transactions of the American Nuclear Society.
• Furfaro, R. (2008). Optimization of the extrapolated-iterative method for the multislab transport problem. In International Conference on the Physics of Reactors 2008, PHYSOR 08.
• Furfaro, R. (2008). Robotic resource exploration is a key to human expansion through the cosmos. In Proceedings of SPIE - The International Society for Optical Engineering.
• Furfaro, R. (2008). Wind-based navigation of a hot-air balloon on titan: A feasibility study. In Proceedings of SPIE - The International Society for Optical Engineering.
• Furfaro, R. (2007). Convergence acceleration for keff using power iteration. In Transactions of the American Nuclear Society.
• Furfaro, R. (2007). Extrapolated iterative solution of the transport equation in inhomogeneous media. In Transactions of the American Nuclear Society.
• Furfaro, R. (2007). The Biological Oxidant and Life Detection (BOLD) Mission: An outline for a new mission to Mars. In Proceedings of SPIE - The International Society for Optical Engineering.
• Furfaro, R. (2007). Tier-scalable reconnaissance missions for the autonomous exploration of planetary bodies. In IEEE Aerospace Conference Proceedings.
• Furfaro, R. (2006). Fuzzy logic expert system for tier-scalable planetary reconnaissance. In SpaceOps 2006 Conference.
• Furfaro, R. (2005). Model-based neural network algorithm for coffee ripeness prediction using helios UAV aerial images. In Proceedings of SPIE - The International Society for Optical Engineering.
• Furfaro, R. (2005). Probabilistic and generalized regression neural networks for non-multiplying material identification. In Transactions of the American Nuclear Society.
• Furfaro, R. (2004). Radiative transfer theory in dense plant canopies: A neural network application to coffee cherry ripeness estimation, invited. In Transactions of the American Nuclear Society.

Presentations

• Amato, D., Rosengren, A. J., & Furfaro, R. (2018, July). Solving the main problem in satellite theory through recurrent neural networks. 42nd Scientific Assembly of the Committee on Space Research (COSPAR). Pasadena, California.
• Furfaro, R. (2016, Spring). Mars-Lunar Greenhouse (M-LGH) Prototype at the University of Arizona: Status and Path Forward.. 7th International AgroSpace Workshop Mars – A Long Way to Go. Sperlonga (LT) [former] Santa Maria Church, May, 26th – 27th 2016.
• Schulze-Makuch, D., Fink, W., Head, J. N., Houtkooper, J. M., Knoblauch, M., Furfaro, R., Fairen, A. G., Vali, H., Sears, S. K., Daly, M., Deamer, D., Schmidt, H., Hawkins, A. R., Sun, H. J., Lim, D. S., Dohm, J., Irwin, L. N., Davila, A. F., Mendez, A., & Andersen, D. (2012, June). The Biological Oxidant And Life Detection (BOLD) Mission: A Proposal For A Mission To Mars. NASA Workshop at Lunar and Planetary Institute on “Concepts and Approaches for Mars Exploration”.

Creative Productions

• Giacomelli, G., Kacira, M., Furfaro, R., Sheehy, C., & Sadler, P. (2014. "EARTHLIGHT" Documentary. Tucson Loft Theater viewing; DVD format released; online at CALS website. University of Arizona: College of Agriculture and Life Sciences. http://cals.arizona.edu/earthlight/
  More info

  Earthlight documentary released in July 2014 to bring awareness about the need for sustainable food systems on earth and the possibility of creating such systems in the future on our moon or other planets.This documentary was awarded an Emmy in October, 2015. See Cody Sheehy accepting the award here: https://twitter.com/EarthlightDoc/status/657621949137448960/photo/1