ModPak: Modular Spacecraft with Variable Packout Capability for Flexible On-Orbit Servicing and Remediation

In 2017, Nanoracks and its team was awarded a feasibility study from NextSTEP-2 Appendix A with a focus on repurposing upper stages to be used as orbital platforms known as Outposts.  This effort represents the Nanoracks approach to orbital debris. Nanoracks’ intends to support the burgeoning space economy by making the most efficient use of materials on orbit. The capability to extend or expand the use of hardware already on orbit will allow for orbital debris to serve a purpose, reducing the wasteful effect of limited-use spacecraft. Both of these effects will help mitigate the risks associated with space debris in a way that provides economic value. Nanoracks, in collaboration with the University of Maryland Space Systems Laboratory (UM SSL), proposes an investigation of a spacecraft called a ModPAK featuring modular systems to supplement Resident Space Objects (RSOs) in response to the X21.S solicitation referred to as Orbital Prime. The vision for the Outpost program is to field a platform in space for a broad range of purposes, both foreseen and unforeseen. A ModPAK is a derivation from the Outpost concept that is intended to attach to RSOs and provide various functionality. The ability to add functionality to these RSOs will extend the life of existing space hardware and eliminate the need for some new hardware. The current mode of unreplenished, limited-use spacecraft leads to the orbital debris environment of today. Additional propulsion, space domain awareness, communications, power, and attitude control are all functions that can be added to a RSO using a ModPAK. The intent of this study is to analyze how to integrate a universal interface into an Outpost to create a ModPAK. This, along with follow-on investigation, will allow for the addition of a fuel storage capability to the Outpost platform, which can then greatly expand the potential operations, structures, and concepts that the Outpost can facilitate. The primary goal is to define a top-level system architecture definition for the ModPak which maximizes its utility as an on-orbit servicer and, therefore, contributes to the mitigation of space debris. This effort will involve characterizing potential users, formulating their use cases into top-level requirements, designing critical interfaces, and generating the system architecture. The University of Maryland Space Systems Lab will contribute trade study and systems analysis based on its extensive experience with space robotics and space systems design. Nanoracks will focus on the detailed design of fundamental interfaces. Nanoracks will also collaborate with other Voyager companies as they pursue related projects in an effort to make all design solutions mutually compatible. The final product of this study will be a top-level architecture as defined in a report detailing the most essential use cases, critical trades, design decisions, and path forward.