Description: In response to the 2024 NASA SBIR Phase I solicitation subtopic Z8.09, "Small Spacecraft Transfer Stage Development", Advanced Space, LLC proposes to develop mission architectures and requirements for customizing a low-cost rocket transfer stage that will deliver small spacecraft to nontraditional orbits and provide position, navigation, timing (PNT) and communications relay services for the deployed small spacecraft. The proposed solution defines a set of modular mission architectures and concepts of operations (ConOps) that match launch vehicle and transfer stage capabilities to the deployment of a primary payload in its destination orbit. The proposed solution will result in a mission-planning system that defines the required capabilities of the transfer stage to satisfy any given design reference mission (DRM). Mission destinations to cislunar space impose cumbersome propulsion, navigation, and communication requirements on small spacecraft. Propulsion to reach the destination orbit, longer communication distances, and lack of Global Navigation Satellite Systems (GNSS) are significant contributors to increased spacecraft size, weight, power, and cost (SWAP-C). These hindrances drive the need to develop services that facilitate operating small spacecraft in these unique mission destinations. Previous awardees of this subtopic have designed transfer stage platforms to provide small spacecraft enough energy to reach cislunar space, lunar orbit, and beyond, but have not yet exploited the possibility of using the same hardware to provide needed communications and navigation services for these SWAP-limited missions as they embark on journeys to increasingly distant destinations. Any relief of these needs for small spacecraft will contribute to increasing the scientific or commercial return of the primary mission.

Benefits: Applications with NASA include the Near Space Network Service (NSNS) model, future missions with relay communication requirements in the Commercial Lunar Payload Services (CLPS) program, and payloads for upcoming missions sponsored by the different directorates, much like the secondary payloads on Artemis I. For NSNS, NASA envisions a constellation of satellites at the Moon that can provide communications and navigation services throughout cislunar space and across the Moon's surface. Eventually, when enough missions are sent to the Moon using this architecture, several nodes will be orbiting near the Moon with the agency's desired communication and navigation services. These missions will incorporate NASA's LunaNet Interoperability Specifications, which will push the standards forward and identify gaps in the standards, which is critical for the future of the lunar economy. The CLPS missions can significantly benefit from this architecture. While most CLPS missions will have dedicated transfer ability, those on the lunar far side have specific relay needs. Existing nodes of this architecture already at the Moon or separately launched relay satellites with the transfer stage's redundant relay capability will reduce the complexity of mission planning for far-side landings significantly. On the Artemis I mission, the Space Launch System vehicle flew ten different low-cost CubeSats from different NASA directorates. Three other missions were supposed to be on the launch but were incomplete by the integration deadline. The proposed transfer stage will provide a dedicated stage for the types of low-cost NASA CubeSat missions like the three that missed the deadline and will enable relay services to provide these low-cost missions with precise navigation and reliable communications back to Earth. Most importantly, this technology will be an enabler for NASA missions that have been infeasible in the past due to overburdening communication and propulsion requirements.Applications for the commercial and national security markets include lunar users from the DARPA LunA-10 program; international Moon landings by JAXA, ISRO, SpaceIL, and KARI; deep-space missions to Mars science applications; and space domain awareness applications from passive RF signatures. Growing commercial interest in returning to the Moon will be enabled by small satellites with reduced cost and complexity. Additionally, DARPA is conducting a LunA-10 study, which is investigating developing lunar infrastructure over the next 10 years. One component that must be addressed to make this infrastructure a reality is reliable communication and navigation services. This transfer stage can deliver components of these services to lunar orbit to support other the LunA-10 architecture as well as loiter near the Moon to provide communication and navigation services themselves. This is extensible to international Moon landings similar to the potential applications to CLPS missions. Other applications in national security include having several orbiting nodes with significant antenna hardware. This increases the likelihood of picking up signals from nefarious satellites in cislunar orbits that are not transmitting directly back to Earth.