Jeffrey E. Van Cleve, Ball Aerospace; David P. Osterman, Ball Aerospace; Anna Lawitzke, Ball Aerospace; Jacob D. Griesbach, Ball Aerospace; Christopher J. Grant, Ball Aerospace; Colleen Olson, Ball Aerospace; James Contreras, Ball Aerospace
Keywords: Cislunar, Imaging, Sensors, Optical Systems, Space Domain Awareness, Lunar Lander, LUNINT, Space Situational Awareness, lunar regolith
Abstract:
As spacefaring nations and non-state entities expand their activities into cislunar space, and to the resource-rich surface sites near the lunar poles, a corresponding need to observe and predict activity in this region will emerge. In our AMOS 2021 paper, we found that a merit function, weighted by the expected amount of scientific and resource exploration activity and by the difficulty of observing regions close to or obscured by the lunar disk, assigns the highest marginal merit to an observatory near the South Pole of the Moon. We also found it was cheaper and more robust to have proliferated solar-powered observatories than a few nuclear-powered observatories, for the purpose of near-continuous availability throughout the month and year. In this paper, we look beyond average performance to more granular details of solar illumination, communication, site selection, mission operations, and sensor availability gaps. We tell the story of two such observatories functioning together as the Shackleton Space Domain Awareness Station, on opposite sides of the peak of persistent illumination on the rim of Shackleton Crater (longitude 196.7, latitude -89.685), each of which will detect near-Moon space objects brighter than visual magnitude 12.3 and observe activity within the crater itself. While other permanently-shadowed regions (PSRs) may have comparable or greater resources, the preponderance of evidence shows the South polar region is much richer in resources then the North polar region (Brown+, 2022 Fig. 4) and a Shackleton station centrally located in the polar region at the pole itself — can watch comings and goings in the skies above all resource-rich South Pole region PSRs. The importance of this location is validated by the selection of the Shackleton-de Gerlache Connecting Ridge, just a few km away, for the landing site of NASAs PRIME-1 lunar water mission. This story plays out over the year, with topographic rising and setting of the Earth, Sun, the Lunar Gateway, and LunaNet comm relays, based on imagery and digital elevation maps from the Lunar Reconnaissance Orbiter (LRO). The fine structure of this timeline is used in polar operations planning examples such as the Commercial Lunar Payload Services (CLPS) mission TO-19C (Haworth Crater, longitude 361, latitude -86.9), which hosts Balls L-CIRiS lunar surface thermal imaging camera. With this concept of operations, we discuss
Fisheye zenith camera detection of fast overflights of objects in low lunar orbit or on landing trajectories from Chu+ (2017), which are tied to the center of the richest South pole PSRs identified by Brown+ (2022)
Imagery, gas (Farrell+, 2021), and dust (Metzger, 2020) signatures of vehicles landing and taking off near the South Pole
High Dynamic Range (HDR) optical imagery of surface activities around Shackleton, including the iPSR interior. This imagery can be performed by the gimballed Wide Field of View (WFOV) camera used for the baseline SDA search mission, or by a high-resolution narrow FOV camera added to the instrument suite.
Thermal surface imagery, especially of activities in the PSR.
The tradeoff between polar field of regard (FOR) and direct LOS communication to Earth, if such a capability is desired before high-bandwidth lunar comm relays are available. As an example, Shackleton has excellent FOR, but the Earth is below the horizon roughly half the month, while the ridge between Malapert and Haworth Crater has difficulty seeing objects on the far side of the Moon or in Earth-Moon Lagrange point 2 (EML2) but has direct-to-Earth comm >90% of the month. Similarly, Earth comm for the mission duration constrains all 3 near-term NASA missions: CLPS TO-19C (L-CIRiS), PRIME-1, and VIPER
We conclude with progress towards implementation, including prospects for night survival CLPS following the first successful CLPS mission.
Date of Conference: September 27-20, 2022
Track: Cislunar SSA