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Wednesday, January 10, 2024

Peregrine is Not Dead Yet

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The Peregrine lunar lander is en route to the moon, and already in excess of 192,000 miles from Earth on a trajectory that will have the satellite at the moon in around two weeks.  

The lander's trajectory includes a "phasing loop" around Earth, which "goes out to lunar distance, swings back around the Earth and then cruises out to meet the moon," Astrobotic wrote in today's update. "This trajectory reaches the moon in about 15 days post-launch."

Peregrine, of course, launched early Monday morning on the Cert-1 flight of ULA's Vulcan Centaur.  After the second stage separated and the satellite began using its onboard propulsion system, the troubles began.  Astrobotic has concluded the problem was caused by a stuck valve which caused the oxidizer tank to rupture.  That led to their inability to control the satellite.  

While the company says they have 35 hours of fuel onboard, it's apparently still leaking.  That means the mission will not be capable of landing on the moon, and they're trying to salvage as much of the 20 other payloads as they can.  NASA put five science instruments, out of the 20, onboard via its Commercial Lunar Payload Services (CLPS) program.   

Peregrine was the first CLPS mission to get off the ground.  The next CLPS mission will apparently be the Intuitive Machines IM-1 lunar lander currently scheduled to launch on a Falcon 9 NET February 10. 

The other side of saying they have 35 hours of fuel left is that doesn't mean the probe has 35 hours left to live.  On Monday, they said they had 40 hours of fuel left, so the rate of usage isn't one hour of fuel per hour on the clock.  Which is not to say it will last the 15 days post launch until it reaches the moon, either. 


 

14 comments:

  1. What is with the whole 'stuck valve' thingy? Is the aerospace industry buying them cheap from Wish.com and other ChiCom platforms?

    Seriously, a stuck valve? They didn't test to failure a critical component like a fricken valve?

    What is wrong with people?

    And now we see why SpaceX believes in destructive testing.

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    1. Must have bought them off-the-shelf from Horror Freight!
      Gotta admit this doesn't look too professional.

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    2. Horrible Fright has a better track record than whomever is supplying the US Aerospace Industry with valves.

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  2. The first SpaceX Falcons & Starships failed as well

    All these current landers are one-of-a-kind bespoke bits of gear, by people, who despite the best of intentions and effort, have never done this (extremely difficult) task before.




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    1. Bingo. Important point, along with matism's (currently) second comment down. This is probably in some report somewhere but finding it and integrating this seemingly obscure but critically important point into the procedures isn't easy.

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  3. Well, here's hoping they can throw out the smaller satellites into orbit or wherever they need to go. Not a total loss... yet.

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  4. I would merely note that the OXIDIZER valve is what supposedly failed. Hypergol oxidizer is frequently N2O4, which has a habit of leaching out iron from its storage container. That iron then tends to precipitate out, causing stickage in moving parts. Shuttle had problems with same in its early days.

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    1. We had MMH and N2O4 on the Minuteman missle's MIRV platform, so I am somewhat familiar with it. The birds sat in a temperature-controlled environment (the launch tube) for decades and decades until ready for use, so you would think Astroiibotics designers would be able to handle the hypergolics without failing...
      Probably went the cheap route, or didn't realize/know the precipitation problem. I wonder how long the lander sat after the hypergolics were loaded, could be a factor.
      These younger kids need to sit at the feet of us Old Farts to learn the tricks of the trade. Right, SiG? ;P

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    2. As long as they KEEP OFF MY LAWN!!

      Just kidding. One glance at it tells my neighbors I don't give a damn about my lawn.

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    3. The most common source of the iron getting into the N2O4 is from GSE.
      Shuttle had LONG hypergol lines to the pads from the fuel farms. Those lines had theoretically been passivated during construction. However, iron nitrate precipitation on tank screen showed the error of that claim. Had to heat up the N2O4 in the storage system and then circulate it throughout the lines and through a molecular sieve. Fun times!

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  5. Their website indicates this spacecraft has two fuel and two oxidizer tanks and a pressurization tank of helium. Unlike your car’s gas tank there are no fuel pumps in these propulsion systems. The propellant tanks are pressurized with helium and the gas pressure pushes the fluids out of the tanks to feed the thrusters. Any propellant tank which is ruptured is unable to be pressurized with helium, and since no pressure equals no fluid flow the ruptured tank is useless.

    I don’t understand why all these propulsion issues are occurring. There are well established companies such as Moog who make spaceflight qualified hardware, such as valves, regulators, fill and drain valves. Yes, the hardware is expensive but it is reliable. It almost sounds like these systems are being designed by newbies who think they are smarter than everybody else who has ever tackled the same problem. If that’s the case all I can say is how did that composite submersible work out?
    CP

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    1. Valves do not CARE how good they are when they are plugged with iron nitrate!
      But understand that it cost MONEY to space qualify hardware, and everyone seems to rant about how great SpaceX is by saving costs...

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    2. Iron nitrate is a long term storage issue and was never a worry with spacecraft propulsion systems. On the other hand particulate contamination of the fluid passages was a huge concern because if a particle became imbedded into a valve or regulator seat you’d get a leaky valve or regulator.
      CP

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    3. And if the iron nitrate precipitates out on a filter in the flight system, you get a fluid blockage.

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