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Starship Integrated Flight Test 2 at 7 Am Central Time

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Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#481

Post by kobalsky »

Geojim wrote: post #475
geocrasher wrote: post #78

Second stage lost, looks like the flight termination system did its job. Unknown as to why yet. Going to be very very interesting to see the data that's released from this as well as all the higher quality video/stills that surface.

Isn't an exploding rocket in space a bad thing - ie debris everywhere? I know space is big but aren't there now a few thousand more pieces of space junk to track. I suppose they're worried about a starship landing on someone's home - but still seems a tad premature.

it was not in orbit yet so I think everything should fall back down to earth.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#483

Post by ceejayoz »

x86x87 wrote: post #361
ceejayoz wrote: post #343

Earlier quoted context omitted.

There's no "objectively" here. It's all feels. Objectively , this test successfully demonstrated the water deluge system, an intact launch pad, all engines on the first and second stage igniting and staying lit, stage separation, hot staging, and a long burn nearly to orbital speeds. That's a pretty good list of ticked boxes. They very openly stated they didn't necessarily expect it to get all the way to splashdown.…

Objectively, for any test to be judged a failure or success you have to define the outcome you want upfront. If you do not any amount of mental gymnastics you you after the test does not matter. It does not matter you call it a win if you are not respecting other opinions that this is a fail.

Here's NASA the day before launch:

https://arstechnica.com/space/2023/11/what-nasa-wants-to-see...

> "Tomorrow is a test and we’re going to learn a lot either way," Lisa Watson-Morgan, who manages NASA's Human Landing System program, told Ars in an interview this week. "We’d love to see it go off perfectly, but frankly, if it doesn’t, it’s still going to be a great learning event, and it still will give us progression on the schedule for the different flight tests, and then we’ll know the areas we need to more deeply penetrate.”

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#484

Post by wheelerof4te »

lern_too_spel wrote: post #477
wheelerof4te wrote: post #460

Earlier quoted context omitted.

[flagged]

Wikipedia has an article just for you. https://en.wikipedia.org/wiki/Third-party_evidence_for_Apoll... The real trick would have been sending the astronauts on a rocket into Earth orbit for over a week without being detected by Soviet radar operators, who would have been more than eager to share the coordinates with the world, and then somehow sending radio signals back to Earth always from the direction of the moon.…

[flagged]

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#485

Post by cratermoon »

dotnet00 wrote: post #458
cratermoon wrote: post #451

Earlier quoted context omitted.

> What you count as success depends on what your goal is Yes. My point is that the bar seems pretty low for Starship, and it's not clear why. Yes, some of the ways they are doing things are new, but overall, building large multi-stage rockets is 50s tech.

The "50s tech" was not based around easily reusable systems. It was all based on explosive bolts, solid fueled ullage motors etc. On top of that the fuel was much easier to work with and did not involve needing to be able to handle pressurization and sloshing during flips. It's 50's tech only in the same way that a Ryzen CPU is 70's tech.

Just for a minute, then, let's think like engineers and not Starman Jones. Granted it was a test flight: so what were the objectives of the flight, how man y of them did it achieve, and how many were not? Get beyond calling it a success or failure and talk about what worked and what didn't.

> the fuel was much easier to work with

This is a technical detail where I hard disagree. The oxidizer was liquid oxygen, so that's the same. The fuels were either RP-1 or hydrogen. Methane is somewhere in between those two in difficulty. kept at -180 °C, compared to -253 °C for hydrogen, and LOX is LOX. In the Saturn V, sloshing of the RP-1 led to the Pogo Effect, but that was solved[1]. Granted it didn't involve the maneuvers of the Starship first stage, but in some ways it was worse, because it happened during full thrust at the end of the boost stage, not after separation. You can read a lot more about NASA's experience with pogo at [2], but it's worth noting that it continued to crop up as late as Apollo 13, when the 2nd stage center engine shut down early as a result.

Yes, SpaceX is doing some things new, but the engineering experience is definitely something from the 50s and 60s.

1. https://www.nasa.gov/history/50-years-ago-solving-the-pogo-e...

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#486

Post by bronson »

lisper wrote: post #439
pantalaimon wrote: post #371

Earlier quoted context omitted.

All but one engine successfully relit (the outer engine ring has no re-light capability) but they started to fail quickly afterwards. Scott Manley also has the theory that the maneuver caused a sloshing motion of the fuel and the water hammer ruptured piping on the engines, causing a cascading failure. https://www.youtube.com/shorts/7LYw6gU65ac

I love how at the end of the video the SpaceX announcer refers to what just happened as a "rapid unscheduled disassembly of the booster".

That's an industry term. Lithobraking is too.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#487

Post by yodsanklai »

I understand that having these prototype rockets blow up may be a cost-efficient way of improving the design. However, I still wonder how much of that was really expected, and what it says about the project progress. Also, how many successful launches will they consider enough before putting people's life at risk. I wouldn't feel super confident going into that rocket after having seen it blow up many times.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#488

Post by chrisco255 »

yodsanklai wrote: post #487

I understand that having these prototype rockets blow up may be a cost-efficient way of improving the design. However, I still wonder how much of that was really expected, and what it says about the project progress. Also, how many successful launches will they consider enough before putting people's life at risk. I wouldn't feel super confident going into that rocket after having seen it blow up many times.

The Falcon 9 rocket started off the same way. They blew up on launch and on landing multiple times early in its development, but has now become perhaps the most reliable and certainly the most reusable rocket model in history, with hundreds of launches per year now with no incidents.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#489

Post by mlindner »

yodsanklai wrote: post #487

I understand that having these prototype rockets blow up may be a cost-efficient way of improving the design. However, I still wonder how much of that was really expected, and what it says about the project progress. Also, how many successful launches will they consider enough before putting people's life at risk. I wouldn't feel super confident going into that rocket after having seen it blow up many times.

The first planned use for Starship will likely be launching Starlink satellites. And there's no immediate plans to directly launch with humans on board.

I'd personally ballpark that there will be well over 20 launches before anything regarding humans is considered.

Re: Starship Integrated Flight Test 2 at 7 Am Central Time

#490

Post by invalidator »

Geojim wrote: post #475
geocrasher wrote: post #78

Second stage lost, looks like the flight termination system did its job. Unknown as to why yet. Going to be very very interesting to see the data that's released from this as well as all the higher quality video/stills that surface.

Isn't an exploding rocket in space a bad thing - ie debris everywhere? I know space is big but aren't there now a few thousand more pieces of space junk to track. I suppose they're worried about a starship landing on someone's home - but still seems a tad premature.

As long as it hasn't achieved orbit, all the pieces will end up on an elliptical track with the lowest point inside the atmosphere. Some stuff might get flung way up, but it would still need another maneuver (requiring working engines) near the highest point to circularize the track to prevent it from coming back down.

There's not much ambiguity for when to destruct. It's just: has it gone far enough off course that it could free-fall outside the predetermined borders where it's acceptable to crash? Then it's time to blow it up so it doesn't fly any farther.

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