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It appears test flight 8 may happen today Wednesday 2025/03/05...
SpaceX Starship Flight 8 Tomorrow and New GigaBay Work
March 4, 2025 by Brian WangAs flight testing and development of Starship continues at Starbase in Texas, SpaceX is building a new integration facility, called Gigabay, next to its HangarX location at NASA’s Kennedy Space Center. Additionally, SpaceX plans to complete the Starship launch pad at Launch Complex 39A (LC-39A) at Kennedy Space Center this year while the Environmental Impact Statements continue for potential Starship flight operations from both LC-39A and Space Launch Complex 37 (SLC-37) at Cape Canaveral Space Force Station (CCSFS).
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I've ben keeping up with the evolving story about IFT 7 the latest engineering info I've seen has pointed the finger at a massive vibrations problem--some 5X greater than the test stand results. Vibrations --> metal fatigue and cracking, which apparently caused the fuel leaks, leading to the RUD.
The Thursday flight on 3/6/2025 was earlier announced, but there was a damaged part during the stacking which may result in another day or 2 delay. WAS!!
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I rather suspect that the source of the leaks may be the stage itself, not the plumbing on the engine. But that's just a suspicion.
When they test engines in McGregor, it's just the one engine at a time. Usually the burns are around 23-4 minutes long. Sometimes shorter. There is no stage.
The first time there is a stage and more than 1 engine is the static fires at Boca Chica. Even that may not reveal excessive vibration, which for the first stage may stem from thrust interacting with supersonic aerodynamics.
Not where excessive vibration might be coming from on the second stage out in vacuum. I suspect SpaceX doesn't yet know, either.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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According to what little I have seen, Flight Test 8 ended with a successful booster catch, but a second loss of the Starship upper stage.
I think it might now be clear that there are engine problems in both stages, and some sort of stage-related excessive vibration problem in the Starship upper stage. I think it is also clear that SpaceX has no clue what the vibration problem really is.
I will have to find the SpaceX video and go see it, before I can be specific about anything. The news reports vary too much.
GW
Last edited by GW Johnson (2025-03-06 19:02:05)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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The video on the SpaceX website is disabled to black. I cannot watch it.
As for the two failures, bear in mind that most flight vehicle failures in flight are due to multiple things acting together. Having only a single cause is unlikely in the extreme.
That being said, after flight 7, they made alleviating changes to the vehicle for flight 8. Those did not work, apparently. Which lends strong support to the suggestion that the real causes (plural!) were not what they assumed after flight 7, which was about leaks in engine plumbing.
There was a vehicle design change after flight 6. The vehicles for flights 7 and 8 were longer, with larger propellant tanks. Which raises the specter of some sort of slosh or other unstable-surface mode in the propellant tanks causing the vibration instead, and perhaps causing the fatal leaks to be in weld joints of the lower tank aft bulkhead instead of the feed plumbing. The larger propellant masses involved would likely amplify any such effect. It's only speculation, but a real possibility that they need to explore.
If it were me, I'd re-fly the older Starship upper stage design on flight 9, with the smaller tank volumes and shorter length, but with the improvements they made to the flaps, hinges, and heat shield. If that makes the ascent successfully, when the larger design did not twice in a row, that would pretty well nail it to the dynamics of the larger tanks vs smaller tanks.
If it's some sort of liquid-sloshing in the tanks that is the source, then a change to the baffles is indicated. And the tank structures in and adjacent to the aft bulkheads may need reinforcement to better resist the unanticipated loads. They need to instrument for these possible effects, probably to include in-tank camera views, and some strain gages and suitably-located pressure sensors.
That's not to say there might not also be failures in the engine plumbing too. But whatever is going on there, is apparently being overwhelmed by something else they have not identified yet.
This sort of thing happens often in experimental flight test. It shows up more often when you make too many changes to the vehicle design between tests, too early in the flight test program. In this particular case, it may also trace to believing too strongly in computer code outputs, by engineers who cannot detect a garbage-in/garbage-out problem because they have not done enough pencil-and-paper design analysis. Or cannot, because they were only taught how to use software packages.
That problem has existed for some long time now. I saw it during the Rogers Commission hearings after the Challenger loss. The thermal-structural model they had for the O-ring joint said it was OK to fly cold. But their model did NOT match what they built! And THAT is where the garbage got into the computer, making the output garbage, too!
GW
Last edited by GW Johnson (2025-03-07 09:07:16)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
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GW Johnson,
I can watch video on the SpaceX website. When you click the REWATCH button it goes to a new black page, then after a second or two opens a video window. I use Firefox for my browser on Windows 10. Fully updated, version 136.0 (64-bit).
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One friend asked if NASA will stop using SpaceX for their mission to the Moon. With everything Elon Musk has done with DOGE, many people are dumping Tesla stock. But I pointed out NASA is not focused on making money, they're focused on results. And SpaceX has delivered. However, developing Starship is taking a long time. Is it time to consider an alternative?
I thread that I posted in 2016: Moon mission today - Dragon & Mars hab
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This YouaTube channel is not SpaceX, but the video is the feed from SpaceX with no commentary, no additions, no deletions, the entire SpaceX fees from introduction to SpaceX terminating their video.
YouTube: Replay! SpaceX Starship launches on flight 8, catches booster but loses ship again
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