SpaceX flight testing in South Texas

[MostlyHarmless]

Originally Posted by B Fraser

I think they had their tongue in their cheek when they came up with that one. See also "Falcon Heavy", I bet it is.
I used to describe a situation as "Failure Under Continual Test" ......or FUCT.

I actually thought it ws very sharp of them flogging 2H rockets to customers as "Flight Proven". Not sure it'll wash in Autotrader when I sell my 2016 Golf though :/

[RickNRoll]

Originally Posted by tdracer

Just stumbled across this - puts things into perspective a bit:

Split those figures up by program, Falcon or Starship, and the perspective changes.

[HOVIS]

Originally Posted by Diff Tail Shim

Von Braun was lucky.

He also had a lot of data from the Saturn1 and 1B program to work with.
Also...
In 1972, the cost of a Saturn IB including launch was US$55,000,000 (equivalent to $413,000,000 in 2024). 😳

[Sam W]

Impressive mishap/reentry video of SS8 starting at the 9:30 mark.

https://www.youtube.com/watch?v=xl8p-9sX63E

Well done Spacex.

[MostlyHarmless]

Can't find the article now, but there was some interesting comment regarding the hot spot on the RVac bell - Methane cooled so a failure/leak in that system could explain it.

[ORAC]

I refer you back to the discussion in 994…..

Seems likely to be a vibration problem once ullage levels fall below a certain level leading to cavitation and pipe failure leading to erratic engine surges until the nozzle then complete engine blows.

Presumably they’ll have to find some way to damp the vibrations.

Interesting it didn’t happen to the earlier version of the Starship though - might be a simple reversion to the original methane pipe design.

​​​​​​​https://x.com/gonzopolitician/status...315654868?s=61

[MostlyHarmless]

I gather they've made big changes to the pipework in V2 with 3x RVAC methane downcomers vs just the one.

[B Fraser]

Originally Posted by tdracer

The Saturn V has the rather unique claim that it never experienced a failure that prevented the payload from reaching earth orbit. No other US launch system with more than 10 launches can make that claim.

They lost a lot of F1 engines on the test stand (56 ???) due to issues including combustion instability at the injector plate. The RS25 engines have always achieved orbit, albeit by a very narrow margin at times.

[tdracer]

Originally Posted by RickNRoll

Split those figures up by program, Falcon or Starship, and the perspective changes.

I must have missed where the Starship was declared other than "Experimental".
SpaceX has made no secret that they expect failures of the Starship with their accelerated development techniques. Compare what they've accomplished so far with Starship (including successful recovery of the first stage) with what NASA has done with SLS (with way more money and time). Sure, they were unhappy with the results of the last two Starship launches. But they learned a lot that will be incorporated into future iterations. Right now, NASA doesn't even have plans to be able to fly SLS more than once a year or so.

[tdracer]

Originally Posted by B Fraser

They lost a lot of F1 engines on the test stand (56 ???) due to issues including combustion instability at the injector plate. The RS25 engines have always achieved orbit, albeit by a very narrow margin at times.

The F1 engines were a huge step in technology and size relative to anything that existed previously (as in an order of magnitude in thrust). It was also designed when computers were in their infancy and slide-rules were state-of-the-art. And they eventually figured it out - no F1 engines failed during a launch (although 'pogo' remained an issue).

[ORAC]

https://x.com/nasaspaceflight/status...587286458?s=61

Interesting: SpaceX is looking to hire a Propulsion Systems Engineer, responsible for designing, analyzing, and building feedline system to feed Raptor engines on Starship.

https://boards.greenhouse.io/spacex/...jid=7607806002


​​​​​​​

[B Fraser]

Originally Posted by tdracer

And they eventually figured it out - no F1 engines failed during a launch (although 'pogo' remained an issue).

Yes, 65 engine flights and no losses. The turbopump in one engine had more power than 2 full formula 1 grids, some 55,000 hp ! One pump moved 2,600 litres of propellant a second (1,000 litres of RP1, 1,600 litres of LOX) at a pressure greater than that in the combustion chamber.

The science and engineering involved is incredible.

[ORAC]

Next flight 4-10th April.

[HOVIS]

I'm assuming this is from a fake X account. 😁

[Pilot DAR]

Watching the spashdown took me back to watching the Gemini and Apollo splashdowns in the early days. Watching the lift the spacecraft aboard the recovery ship took me back to watching the Thunderbirds years earlier! Very cool!

[cavuman1]

Spaceflight! We who dare traverse the troposphere, or, with sufficient funding, the lower stratosphere are fully rewarded for the joy of it all. To Fly! To Dream! Mr. Musk and his companions have earned my highest admiration and camaraderie!

- Ed

[ORAC]

Elon Musk:

https://x.com/elonmusk/status/1903481526794203189

We are honing in on the V3 Starship design.

@SpaceX is tracking to a Starship launch rate of once a week in ~12 months. That will yield ~100 tons to @Starlink orbit with full reusability.

​​​​​​​Profound breakthrough.

[cavuman1]

Amazing goal which I hope SpaceX is able to reach. First, the problem of "unscheduled rapid disassembly" needs to be solved.

- Ed

[ORAC]

https://x.com/spacesudoer/status/1905275649561887040

News: SpaceX is reportedly planning NOT to catch Booster 14-1 on Starship Flight 9. The booster will perform a water landing in the Gulf of America.

Booster 14 previously flew on Flight 7, making Flight 9 its second mission and the first time a booster is being reused.

They will skip the catch, but not for the reasons you think. They can catch it, but they want to test a higher angle of attack*, and the safest way to do that is with a water landing.

​​​​​​​[* more horizontal re-entry to lose more speed and need less fuel for landing so more available during ascent. Means the grid flaps will be less effective and may need cold reaction jets for control]

[B Fraser]

Interesting, perhaps they need a pair of grid fins close to the base so they have greater rotational control to vary the pitch and for the final pitch up manoeuvre. The fuel in the tanks will need to slosh to the bottom of those tanks so the engines are not chewing on vapour at the re-light, otherwise, it gets very exciting very quickly and very briefly.