Cooperative control of two active spacecraft during proximity operations

A cooperative autopilot is developed for the control of the relative attitude, relative position and absolute attitude of two maneuvering spacecraft during on orbit proximity operations. The autopilot consists of an open-loop trajectory solver which computes a nine dimensional linearized nominal state trajectory at the beginning of each maneuver and a phase space regulator which maintains the two spacecraft on the nominal trajectory during coast phases of the maneuver. A linear programming algorithm is used to perform jet selection. Simulation tests using a system of two space shuttle vehicles are performed to verify the performance of the cooperative controller and comparisons are made to a traditional passive target/active pursuit vehicle approach to proximity operations. The cooperative autopilot is shown to be able to control the two vehicle system when both the would be pursuit vehicle and the target vehicle are not completely controllable in six degrees of freedom. The cooperative controller is also shown to use as much as 37 percent less fuel and 57 percent fewer jet firings than a single pursuit vehicle during a simple docking approach maneuver

Performance capabilities of a Phase One Automatic Rendezvous and Capture System

This paper presents an analysis of the performance of the existing 'Phase One' AR&C system developed at the C.S. Draper Laboratory for both the rendezvous and proximity operations mission phases. This material has been developed as a result of Draper Laboratory involvement through NASA's Johnson Space Center in the development of the flight proven IGN&C rendezvous systems for Apollo, Skylab, and Shuttle. The development of these systems using Draper computer simulations has required automation of all crew inputs to the IGN&C system and thus provided the unique opportunity to develop and test those system capabilities required for AR&C. This paper expands upon the material in the papers presented by the authors at the NASA Autonomous Rendezvous and Docking Conference held at JSC on August 15-16, 1991

Cooperative control of two active spacecraft during proximity operations

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989.GRSN 406710Includes bibliographical references (leaves 146-147).by Robert J. Polutchko.M.S

Free-Flight Test Results of Scale Models Simulating Viking Parachute/Lander Staging

This report presents the results of Viking Aerothermodynamics Test D4-34.0. Motion picture coverage of a number of Scale model drop tests provides the data from which time-position characteristics as well as canopy shape and model system attitudes are measured. These data are processed to obtain the instantaneous drag during staging of a model simulating the Viking decelerator system during parachute staging at Mars. Through scaling laws derived prior to test (Appendix A and B) these results are used to predict such performance of the Viking decelerator parachute during staging at Mars. The tests were performed at the NASA/Kennedy Space Center (KSC) Vertical Assembly Building (VAB). Model assemblies were dropped 300 feet to a platform in High Bay No. 3. The data consist of an edited master film (negative) which is on permanent file in the NASA/LRC Library. Principal results of this investigation indicate that for Viking parachute staging at Mars: 1. Parachute staging separation distance is always positive and continuously increasing generally along the descent path. 2. At staging, the parachute drag coefficient is at least 55% of its prestage equilibrium value. One quarter minute later, it has recovered to its pre-stage value

A phase one AR/C system design

The Phase One AR&C System Design integrates an evolutionary design based on the legacy of previous mission successes, flight tested components from manned Rendezvous and Proximity Operations (RPO) space programs, and additional AR&C components validated using proven methods. The Phase One system has a modular, open architecture with the standardized interfaces proposed for Space Station Freedom system architecture

A Decision Framework for Allocation of Constellation-Scale Mission Compute Functionality to Ground and Edge Computing

This paper explores constellation-scale architectural trades, highlights dominant factors, and presents a decision framework for migrating or sharing mission compute functionality between ground and space segments. Over recent decades, sophisticated logic has been developed for scheduling and tasking of space assets, as well as processing and exploitation of satellite data, and this software has been traditionally hosted in ground computing. Current efforts exist to migrate this software to ground cloud-based services. The option and motivation to host some of this logic “at the edge” within the space segment has arisen as space assets are proliferated, are interlinked via transport networks, and are networked with multi-domain assets. Examples include edge-based Battle Management, Command, Control, and Communications (BMC3) being developed by the Space Development Agency and future onboard computing for commercial constellations. Edge computing pushes workload, computation, and storage closer to data sources and onto devices at the edge of the network. Potential benefits of edge computing include increased speed of response, system reliability, robustness to disrupted networks, and data security. Yet, space-based edge nodes have disadvantages including power and mass limitations, constant physical motion, difficulty of physical access, and potential vulnerability to attacks. This paper presents a structured decision framework with justifying rationale to provide insights and begin to address a key question of what mission compute functionality should be allocated to the space-based edge , and under what mission or architectural conditions, versus to conventional ground-based systems. The challenge is to identify the Pareto-dominant trades and impacts to mission success. This framework will not exhaustively address all missions, architectures, and CONOPs, however it is intended to provide generalized guidelines and heuristics to support architectural decision-making. Via effects-based simulation and analysis, a set of hypotheses about ground- and edge-based architectures are evaluated and summarized along with prior research. Results for a set of key metrics and decision drivers show that edge computing for specific functionality is quantitatively valuable, especially for interoperable, multi-domain, collaborative assets

Proliferated LEO Autonomy Architecture for Capability with Scalability

A next generation space architecture focused on proliferated low-Earth Orbit (p-LEO) constellations holds the promise of improved situational awareness, responsiveness, and resiliency. A variety of proliferated space constellation efforts are underway in the National Security Space Arena, all demanding innovations in ubiquitous satellite command, control, and communications. Whether communications, science, or defense missions, the expansion into PLEO constellations drives new demands upon autonomy, software, and communications architectures. Previous groundbreaking autonomy work was performed on the Deep Space 1 mission, which eventually led to NASA Mars and Earth Observing-1 autonomy. In Autonomous Rendezvous, Proximity Operations, and Docking (ARPOD), Defense Advanced Research Projects Agency (DARPA)\u27s Orbital Express and the Air Force XSS-10 mission helped establish the state of the art. While similarities exist, mission autonomy for these individual spacecraft missions fundamentally differs from PLEO constellations in their demands and constraints

Relative navigation requirements for automatic rendezvous and capture systems

This paper will discuss in detail the relative navigation system requirements and sensor trade-offs for Automatic Rendezvous and Capture. Rendezvous navigation filter development will be discussed in the context of navigation performance requirements for a 'Phase One' AR&C system capability. Navigation system architectures and the resulting relative navigation performance for both cooperative and uncooperative target vehicles will be assessed. Relative navigation performance using rendezvous radar, star tracker, radiometric, laser and GPS navigation sensors during appropriate phases of the trajectory will be presented. The effect of relative navigation performance on the Integrated AR&C system performance will be addressed. Linear covariance and deterministic simulation results will be used. Evaluation of relative navigation and IGN&C system performance for several representative relative approach profiles will be presented in order to demonstrate the full range of system capabilities. A summary of the sensor requirements and recommendations for AR&C system capabilities for several programs requiring AR&C will be presented

Sagittarius A* Small Satellite Mission: Capabilities and Commissioning Preview

SSCI is leading a Defense Advanced Research Projects Agency (DARPA)-funded team launching a mission in June 2021, dubbed Sagittarius A*, to demonstrate key hardware and software technologies for on-orbit autonomy, to provide a software testbed for on-orbit developmental test & autonomous mission operations, and to reduce risk for future constellation-level mission autonomy and operations. In this paper, we present the system CONOPs and capabilities, system architectures, flight and ground software development status, and initial commissioning status. The system will fly on Loft Orbital’s YAM-3 shared LEO satellite mission, and includes SSCI’s onboard autonomy software suite running on an Innoflight CFC-400 processor with onboard Automatic Target Recognition (ATR). The autonomy payload has attitude control authority over the spacecraft bus and command authority of the imaging payload, and performs fully-autonomous onboard request handling, resource & task allocation, collection execution, ATR, and detection downlinking. The system is capable of machine-to -machine tip-and-cue from offboard cueing sources via cloud-based integrations. Requests for mission data are submitted to the satellite throughout its orbit from a tactical user level via a smartphone application, and ISR data products are downlinked and displayed at the tactical level on an Android Tactical Assault Kit (ATAK) smartphone. Follow-on software updates can be sent to the autonomy suite as over-the-air updates for on-orbit testing at any time during the on-orbit life of the satellite. Communications include GlobalStar inter-satellite communications for low rate task and status monitoring, and ground station links for payload data downloads. Planned demonstrations and opportunities will be discussed