Eric C Pearce

Interests

Research

Space Situational Awareness in Cislunar SpacePhotometric characterization of man made satellitesSpace surveillance systemsHigh speed photometryRapid time domain observational astronomy

Courses

Scholarly Contributions

Journals/Publications

Proceedings Publications

• More info

  The characterization of deep space debris poses a significant challenge in Space Situational Awareness (SSA). To be most useful, characterization should provide actionable information quickly, even under non-ideal observing conditions. Multi-color photometry and the resultant color indices offer the potential to rapidly discriminate between debris and intact space objects such as rocket bodies and satellites. These multi-color techniques can also identify anomalous members of object groups and cue higher fidelity data collections and studies. In this paper, we present the results from our 2020–2021 measurements campaign supplemented by further analysis from our previous 2016–2017 campaign. In 2017-2018, our team began developing and demonstrating rapid multi-color photometry techniques using the Russian SL-12 fourth stage rocket bodies (RB). We demonstrated that anomalous members of our rocket body cohort can be readily identified using only near-infrared (IR) color indices. During late 2020 and early 2021, our team expanded our previous characterization by using both the United Kingdom Infrared Telescope (UKIRT) Wide Field Camera (WFCAM) and the 1–5 m Imager-Spectrometer (UIST). Specifically, we have expanded our data set to include:(a) more SL-12 fourth stage RBs increasing years-on-orbit sampling from our 2016-2017 campaign, (b) Centaur RBs of the same type as the returning RB cataloged as Near-Earth Object 2020 SO, (c) a selection of Molniya communication satellites including the -1K, 1T, -2, and -3 variants, (d) Russian FREGAT and SL-6 upper stage RBs in Molniya orbits, (e) intact payloads selected from satellites using the Boeing HS-376 busses. Our new data set provides us with overlapping broadband IR colors and high-resolution spectra in those same color bands. We carefully chose our targets to include a mix of objects with known compositions to allow the development and evaluation of novel techniques to interpret our broadband near-IR photometry. The addition of Molniya payloads and RBs is a unique addition to existing literature since all previously published studies have focused on objects in geosynchronous orbits. For the first time, we can analyze near-IR photometry with the context of the full resolution near-IR spectra of same-type. We offer insight into refining the spectral bands of interest for characterization and provide an approach to improve rapid discrimination capabilities using substantially more efficient near-IR photometric techniques.

Presentations

• More info

  Our current space situational awareness (SSA) capabilities have evolved and matured since originally being developed in the mid-1950s in response to the imminent launch of the first Rus-sian satellite Sputnik. The development of our ground-based space surveillance systems and techniques were led by a coalition of academic and Government organizations to meet the emerg-ing needs to detect, track, and catalog objects in Earth orbit. Very early in the development of our space surveillance network, the complementary capabilities of optical and radar systems were embraced as a foundational element of our space surveillance network (SSN).Today science, civil, commercial, and military interests are motivating a return to Moon and the unique orbital regime surrounding the Moon and the Earth/Moon Lagrange points. China al-ready has an extensive lunar exploration program, with a lander and rover on the far side of the Moon and a communication relay satellite stationed in an L2 halo orbit. NASA plans to exploit the unique astrodynamics at L1 as a lunar and interplanetary gateway and return man to the Moon by 2024. Commercial interests see a future of providing services and mining product from the lunar polar regions. In time, robust Earth/Moon communication relay and lunar-GPS constel-lations will be deployed. Inevitably cislunar space will become congested, contested, and con-tested. To ensure safety and freedom to operate in this new domain, space-faring nations must es-tablish foundational surveillance, cataloging, characterization, and space traffic control capabili-ties. While our nation’s capabilities to maintain awareness in the confines of the traditional orbits out to the geosynchronous belt is mature, we have essentially no capabilities even to detect ob-jects in the cislunar environment. Many of the same characteristics of cislunar space that enable these missions are the same characteristics that make cislunar space a challenge for SSA. The large distance to cislunar satellites compared to circumterrestrial satellites, and difficult viewing geometries make surveillance and detection of cislunar satellites much more difficult. Equally important, the astrodynamic attributes that allow low-energy transfers in cislunar space and are enabling to the diverse missions proposed are the same attributes that make establishing and maintaining a catalog in cislunar space difficult. These problems are multi-disciplinary problems and offer a new opportunity for the combined talents of academia, our different Colleges, and Government organizations to reinvent SSA in this challenging new domain.

Poster Presentations

• More info

  A turnkey 6.5-m observatory has been developed for broad science applications with predefined performance specifications that can be verified on sky. This observatory can be delivered within five years at a fixed price. By combining academia and industrial partners with extensive experience and enormous investments in infrastructure it is possible to produce a highly valued optimized observatory with cost and schedule certainty. The challenge for scientists now becomes developing the science and instruments and not the observatory.

Others

• More info

  Principle contributor to the optical measurements section of the Satellite Constellations 1 (SATCON1) workshop. The workshop report concludes that the effects of satellite constellations on astronomical research and on the human experience of the night sky range from “negligible” to “extreme.”