[X] My Assistant

[Phil Stooke]

I am starting a new thread for this mission which should fly this year.

Phil

[Thorsten Denk]

Update #6:
"An ongoing propellant leak [...]"
"[...] in a stable sun pointing state for approximately 40 more hours, [...]"
https://twitter.com/astrobotic/status/1744543629392134194

Anything known about what caused this propellant leak?

Thorsten

[mcaplinger]

Anything known about what caused this propellant leak?

I haven't heard anything, and there is not much public detail about Peregrine's propulsion system. But it started right after the system was pressurized and was large enough to disturb blankets. I can think of three root causes: 1) damage during launch vibration (hopefully unlikely since the spacecraft was vibe-tested); 2) propellant migration causing a small explosion that blew a hole in the plumbing; 3) pressure regulator failure leading to overpressurization. Assuming https://www.nasa.gov/stmd-game-changing-dev...in-space-talos/ describes what they ended up flying, the main engines were MON-25/MMH biprops but how the attitude-control thrusters (presumably monoprops) were tied in, I have not seen.

[HSchirmer]

snip
1) damage during launch vibration (hopefully unlikely since the spacecraft was vibe-tested)
snip

I wonder if there might be an unexpected resonance- e.g. when the SpaceX Falcon Heavy launches from Kennedy Space Center, the Vehicle Assembly Building 'squeals' because it randomly has a resonant frequency with the Merlin engine exhaust.
Sorta makes sense that the first actual lift off a brand-new rocket is when you actually find out about the sounds and launchpad acoustics.

[mcaplinger]

Sorta makes sense that the first actual lift off a brand-new rocket is when you actually find out about the sounds and launchpad acoustics.

Normally all of that is determined by analysis and then the testing is done with a lot of extra margin to cover all uncertainties. https://blogs.sw.siemens.com/simcenter/spac...oustic-testing/

And it's not like Vulcan is that different than Atlas in that regard.

What is a little odd is that Peregrine was supposed to be launched with two prototype Kuiper satellites, but after all of the delays, those were launched separately. There didn't seem to be any place to put them on the Centaur, but it seems implausible that they changed the configuration enough to impact Peregrine unfavorably.

If Astrobotic decides this was a vibe-induced failure, I'm sure there will be some finger-pointing.