On January 3, 2023, the SpaceX Transporter-6 launch vehicle arrived at an approximately 528 km circular orbit. VR-5 separated from the launch vehicle shortly thereafter. For several months, VR-5 underwent commissioning and preliminary testing. During this stage, Momentus began to see RCS thruster degradation.
For the next phase (stage 5 of the CONOPS), Momentus had intended to conduct orbit raise maneuvers to achieve a 538 km circular SSO orbit. Unfortunately, because of the continued degradation of the RCS thrusters, Momentus eventually suffered loss of controllability in all three axes. Momentus could, nonetheless, maneuver VR-5. However, such efforts required considerable, additional technical planning and engineering resources to adjust for the lack of attitude control. During this stage, Momentus was able to raise the orbit of VR-5 from approximately 522 km to 524 km over approximately one month.
Because VR-5 could not practicably reach the intended 538 km orbit within a reasonable period of time and without substantial expenditure of engineering and other resources, Momentus ceased its orbit-raising efforts and deployed ZEUS-1 at approximately a 524 km circular orbit in May 2023. Momentus also did not pursue stage 7 of the proposed CONOPS, to raise the orbit further to a 541 km circular orbit.
The impairment of the RCS thrusters did not prevent the operations of the hosted payload. However, because of this and other unrelated issues, the hosted payload testing required more time to conduct. As a result, on April 7, 2023, Momentus sought an additional 120 days to complete its mission. By mid-November 2023, Momentus had completed its primary missions. Because the spacecraft was still operational, Momentus determined that there were benefits from continuing to operate VR-5 for additional testing and demonstration purposes. As a result, Momentus sought authority to extend operations for an additional year.
At the time, Momentus believed it had sufficient company resources to engage in the additional technical planning and engineering necessary to adjust for the failure of RCS thrusters and loss of attitude control and complete the final stage (stage 9) of the proposed CONOPS, i.e., reduce the perigee of VR-5 to 350 km, within the extended period of the license term.
Moreover, because VR-5 had completed its primary missions, and the extension of its operations was intended only for testing and demonstration purposes, Momentus would not earn any revenue to cover the ~$80k per month cost to use ground stations to actively deorbit VR-5. Indeed, incurring such costs for an additional anticipated eight-month period would have depleted significant operating capital.
As a result of these factors, Momentus determined that terminating the operations of the VR-5 spacecraft was the prudent course of action both for safety and financial resource reasons. Accordingly, on February 2, 2024, Momentus placed VR-5 in a safe state with sensors, propulsion system, and payloads powered down and in a minimum power-generation configuration. Momentus also notified the 18th Space Defense Squadron that the satellite was inactive. As of that date, the VR-5 satellite was at approximately a 518 km orbit and is expected to naturally deorbit within 5 years.