Session
Session I: Year In Review
Location
Utah State University, Logan, UT
Abstract
The CAPSTONE mission, currently operating in an Earth-Moon L2 Near Rectilinear Halo Orbit (NRHO), encountered a thruster anomaly in transit to NRHO that resulted in thruster valve remaining permanently open. After resolving the initial anomaly recovering the spacecraft from body rates greater than 120 deg/s, the CAPSTONE team redesigned the thruster controller as well as the spacecraft state machine to enable continued propulsive operations including successful insertion into and sustained operations in NRHO. While the redesign enabled continued utilization of the propulsion system with a stuck thruster, the resulting system presents continued operational challenges within the NRHO environment.
The CAPSTONE space vehicle was designed and built by Terran Orbital, who also serves as the operator of the on-orbit spacecraft. Advanced Space owns and operates the CAPSTONE payload and its software on behalf of NASA, as well as performs mission navigation and maneuver design. The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) satellite is a 12U+ bus containing a pump-fed hydrazine propulsion system from Stellar Exploration, enabling all orbital maneuvers and momentum management for the mission. This includes Trajectory Correction Maneuvers (TCMs) ranging in ∆V from 1 to 20 m/s, and Orbital Maintenance Maneuvers (OMMs) ranging in ∆V from 6 to 60 cm/s. To continue performing these maneuvers after the valve anomaly, critical changes to both flight software and operations processes had to be made to complete mission objectives.
This paper will characterize the challenges of continued operations of a cislunar mission while compensating for undesired force and torque caused by the stuck thruster during all propulsive maneuvers. Discussions will include background on maneuvers in NRHO, the impact of the stuck thruster to maneuver design and maneuver decisions, and the evolution of momentum management strategies for the spacecraft. The pre- and post-anomaly maneuver execution performance will be reviewed with discussion of additional variables impacting the resulting maneuver execution.
Operating in a Unique Three Body Orbit With a Stuck Thruster
Utah State University, Logan, UT
The CAPSTONE mission, currently operating in an Earth-Moon L2 Near Rectilinear Halo Orbit (NRHO), encountered a thruster anomaly in transit to NRHO that resulted in thruster valve remaining permanently open. After resolving the initial anomaly recovering the spacecraft from body rates greater than 120 deg/s, the CAPSTONE team redesigned the thruster controller as well as the spacecraft state machine to enable continued propulsive operations including successful insertion into and sustained operations in NRHO. While the redesign enabled continued utilization of the propulsion system with a stuck thruster, the resulting system presents continued operational challenges within the NRHO environment.
The CAPSTONE space vehicle was designed and built by Terran Orbital, who also serves as the operator of the on-orbit spacecraft. Advanced Space owns and operates the CAPSTONE payload and its software on behalf of NASA, as well as performs mission navigation and maneuver design. The Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE) satellite is a 12U+ bus containing a pump-fed hydrazine propulsion system from Stellar Exploration, enabling all orbital maneuvers and momentum management for the mission. This includes Trajectory Correction Maneuvers (TCMs) ranging in ∆V from 1 to 20 m/s, and Orbital Maintenance Maneuvers (OMMs) ranging in ∆V from 6 to 60 cm/s. To continue performing these maneuvers after the valve anomaly, critical changes to both flight software and operations processes had to be made to complete mission objectives.
This paper will characterize the challenges of continued operations of a cislunar mission while compensating for undesired force and torque caused by the stuck thruster during all propulsive maneuvers. Discussions will include background on maneuvers in NRHO, the impact of the stuck thruster to maneuver design and maneuver decisions, and the evolution of momentum management strategies for the spacecraft. The pre- and post-anomaly maneuver execution performance will be reviewed with discussion of additional variables impacting the resulting maneuver execution.
