Anna M. Lawitzke, Ball Aerospace; Jeffrey E. Van Cleve, Ball Aerospace; James Contreras, Ball Aerospace; David Ramirez, Ball Aerospace; Timothy Finch, Ball Aerospace; Jeremy Correa, Ball Aerospace
Keywords: Cislunar, Astrodynamics, Imaging, Sensors, Optical Systems, Space Domain Awareness, Lunar Exploration, Lunar Mapping
Abstract:
Last year we (Silva+, 2021) discussed a hybrid sensor system which can perform both lunar surface intelligence (LUNINT) and Space Domain Awareness (SDA) missions using two sensors in complementary lunar orbits, each of which has a focal plane array (FPA) which can stare into deep space for long integration times for SDA and can be reconfigured for high line rate virtual Time Delay Integration (TDI) imagery of the lunar surface when near periapsis. We introduced requirements for both SDA and LUNINT missions, in particular the target visual magnitude and revisit rate for SDA and the ground sampling distance for LUNINT, sketched out first-order optical parameters for the telescope, and examined cislunar space volume and lunar surface access for 6 different 2-vehicle constellations. In this paper, we apply the design and concept of operations (CONOPS) options introduced in Silva+ (2021) to
Develop a hybrid FPA architecture road mapfor consultation with FPA vendors and Balls Detector Technology Center
Develop a semianalytic joint merit function which balances SDA and LUNINT performance, for quick concept and parameter set evaluation before design work
Spot-validate merit function against detailed mission analysis
Develop a telescope design which can collect enough photons to quickly sweep the SDA volume, has small enough pixels to usefully resolve targets on the lunar surface, has good straylight rejection, and is buildable and agile.
Build on last years cislunar volume access study by assessing SDA performance against a target deck which includes objects at the Lagrange points, in transit between the Earth and Moon, and in both elliptical and circular lunar orbits with low periapsis consistent with takeoff/landing trajectories or surface-observing sensors. The target radiometric model is a Lambertian sphere.
Build on the surface access component of last years study by including surface illumination as a condition for access in the same 6 cases and calculating the distribution of gap times over the year for a surface target deck that includes objects near the lunar poles including permanently shadowed regions (PSRs). The PSR interior illumination model and thus the threshold geodetic sun angle as a function of topography is developed in a companion paper at this conference (Osterman+)
Present a year in the life observing timeline showing when and where the sensor is looking into space or at the lunar surface, as function of orbital phase, time of month, and time of year for a few representative cases to illustrate the concept of operations.
Date of Conference: September 27-20, 2022
Track: Cislunar SSA