Peregrine Mission One: Review Board Telecon

In this talk

1. 1:21

   Mission flight and controlled return

   Thornton says Peregrine launched on January 8, 2024, and initially established spacecraft communications and began commissioning its propulsion system. After PCV2 opened and closed, helium flowed uncontrollably into the oxidizer tank, which ruptured and leaked. The team stabilized the spacecraft, operated it for about 10 and a half days, and used engine pulses to guide a controlled return over the South Pacific on January 18.

2. 6:45

   Review board identifies the valve failure

   Independent chair John Horack says the 35-person board reviewed flight telemetry, qualification tests, and other mission data using a causal condition method. It concluded that PCV2 most likely lost its seal after vibration loosened a threaded component inside the valve. Testing a spare flight valve reproduced leakage and showed a loosened joint and damaged O-ring and sealing surface.

3. 9:53

   Design and testing decisions before launch

   Basaran describes moving propulsion work in-house amid supplier schedule and technical issues, then changing valve suppliers after leaks appeared during system testing. PCV1 leaked during final proof testing and was repaired; PCV2 did not leak, but remained a tracked low-likelihood risk after spacecraft acceptance tests. Replacing PCV2 would have required extensive spacecraft disassembly and repeating acceptance testing.

4. 17:01

   Changes planned for Griffin

   Clark says Astrobotic is applying review board findings through process, quality, and supplier oversight improvements. Griffin’s propulsion system will use redesigned pressure control valves, upstream pressure regulators, and latch valves that can help control helium flow if a pressure control valve fails. Clark says the changes are intended to address the failure mode and add fault tolerance.

5. 20:22

   Mission lessons and future opportunities

   Clark reports 24 other in-flight anomalies: eight mission-critical, five non-mission-critical, and 11 minor; the operations team resolved the first 13 during flight. Peregrine’s avionics, power, communications, and guidance systems gained cislunar flight experience, and Astrobotic is discussing other uses for the spacecraft. The speakers also discuss Griffin payloads, CLPS lessons, and the board’s view that the decisions made before the failure were reasonable based on the information available.