NASA - CAPSTONE Mission patch.
Sept. 18, 2022
During or shortly after a planned trajectory correction maneuver on Sept. 8, CAPSTONE suffered an issue that caused the spacecraft to tumble beyond the capacity of the onboard reaction wheels to control and counter. CAPSTONE was attempting to communicate with the ground for approximately 24 hours before any telemetry was recovered. After data was received, mission controllers found that the spacecraft was tumbling, the onboard computer systems were periodically resetting, and the spacecraft was using more power than it was generating from its solar panels.
Using NASA’s Deep Space Network, the combined mission team – including Advanced Space, Terran Orbital, Stellar Exploration, and NASA – re-established contact with CAPSTONE and reconfigured the spacecraft’s systems to stabilize the situation while recovery plans are evaluated. CAPSTONE remains in safe mode and now is power positive, meaning that it is generating more power from the solar panels than the system is using. Navigation data collected after the issue began suggests the Sept. 8 trajectory correction maneuver was completed or nearly complete when the issue occurred. This means the spacecraft remains on the intended trajectory and on course to its near rectilinear halo orbit at the Moon.
Image above: CAPSTONE revealed in lunar Sunrise: CAPSTONE will fly in cislunar space – the orbital space near and around the Moon. The mission will demonstrate an innovative spacecraft-to-spacecraft navigation solution at the Moon from a near rectilinear halo orbit slated for Artemis’ Gateway. Image Credits: Illustration by NASA/Daniel Rutter.
While work is ongoing to diagnose the cause of the issue, the team is preparing CAPSTONE to attempt a detumble operation to regain attitude control of the spacecraft. This detumble operation was successfully demonstrated after separation from the launch upper stage in July. A successful detumble would give CAPSTONE control over its orientation, allowing it to orient the solar panels to the Sun to fully charge the batteries of the power used during the detumble. The spacecraft would then orient to the ground and await further instructions. These recovery operations will be further evaluated over the coming days. Recovery timing will be guided by the data and analysis available to maximize the probability of a successful spacecraft operation.
Teams Work Ongoing Recovery Efforts for CAPSTONE
The CAPSTONE team continues work on recovery efforts. The primary ongoing focus now is to heat the spacecraft’s propulsion system, which dropped below its operational temperature limit following the initial issue that put the spacecraft into safe mode on Sept. 8. Over the past few days, CAPSTONE’s power – though limited by the orientation of the spacecraft in its spin relative to the Sun – appears to be sufficient for heating of the propulsion system. Once the spacecraft propulsion system temperature has been at 41° F (5° C) for at least 12 hours, the team will further evaluate the system for use in the recovery operation. Communications with the spacecraft have also improved, providing mission teams with more data from the spacecraft. Teams are evaluating the data to determine the cause of the issue and design recovery procedures to avoid similar problems during the attempted recovery operation.
Related articles:
Mission Team Determines Cause of Communications Issues for NASA’s CAPSTONE
https://orbiterchspacenews.blogspot.com/2022/07/mission-team-determines-cause-of.html
Following Communications Recovery, NASA’s CAPSTONE Prepares for First Maneuver
https://orbiterchspacenews.blogspot.com/2022/07/following-communications-recovery-nasas.html
NASA’s CAPSTONE on the way to the Moon
https://orbiterchspacenews.blogspot.com/2022/07/nasas-capstone-on-way-to-moon.html
CAPSTONE Launches to Test New Orbit for NASA’s Artemis Moon Missions
https://orbiterchspacenews.blogspot.com/2022/06/capstone-launches-to-test-new-orbit-for.html
Related links:
Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment (CAPSTONE): https://www.nasa.gov/capstone/
CAPSTONE NASA blog: https://blogs.nasa.gov/artemis/tag/capstone/
Image (mentioned), Text, Credits: NASA/Sarah Frazier.
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