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Starship's Third Flight Test [video]

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Re: Starship's Third Flight Test [video]

#171

Post by dotnet00 »

iwontberude wrote: post #147
dotnet00 wrote: post #145

Earlier quoted context omitted.

That's impressive revisionism. Where's the Soviet reusable launch vehicle that is half the price, is able to reuse even one stage and takes less than a month to refurbish?

Nevermind

The latest Soyuz revision is ~$50m per launch, it has a payload less than half of a Falcon 9 that lands on a droneship, and ~2/3rd of a Falcon 9 that returns to launch site. Making it twice the cost per kg. The highest flight rate it has ever achieved has been 2/month. It has a 96% success rate.

The latest Falcon 9 revision is ~$67m per launch. Lately it flies every ~3 days. Over the past year it has flown ~100 times. It has a 99.4% launch success rate, and a 98% landing success rate.

Clearly this shows that the Russians are superior.

Re: Starship's Third Flight Test [video]

#172

Post by Laremere »

DarmokJalad1701 wrote: post #151
travisgriggs wrote: post #126

Earlier quoted context omitted.

I wouldn’t classify the re-entry survival problem as icing. But otherwise, I agree with you.

They can launch payloads that bring in revenue while working on that problem. There is a good chance they put a bunch of Starlinks on the next flight.

They might do one to test deployment, but it'd be a throwaway. Their relight test was skipped (not said why), so they still don't have confirmation they can control where Starship re-eneters. Until that happens, it's very unlikely they'll target actual orbital velocity. The Starlink satellites do have thrusters, but they're ion engines, so not nearly enough thrust to get that last bit into orbit before they'd re-enter.

Re: Starship's Third Flight Test [video]

#173

Post by dylan604 »

Laremere wrote: post #162
travisgriggs wrote: post #142

I was surprised that during the initial ascent footage from the fin-cam, you can see that the grid fins are out. Do they not fold back on ascent? Or possibly drag on one side to arc over? Just seems weird to have your “drag device” deployed during ascent.

Grid fins aren't drag devices. They are control surfaces. As long as they are oriented so the fins are aligned with the airflow, they have no effect on orientation. The benefit of not folding them in is one less part that can fail. There might be a slight reduction in drag by folding them in, but not much and apparently not worth it.

I'm guessing 33 Raptor engines won't feel the effect of whatever drag those fins might produce. Instead, they'll just drag that drag into space

Re: Starship's Third Flight Test [video]

#174

Post by ajross »

DarmokJalad1701 wrote: post #167
Laremere wrote: post #148

Earlier quoted context omitted.

Parent's (correct) point is that it isn't a matter of the ascent trajectory. They can't leave the Starship up in orbit, and where it reenters needs to be controlled.

> They can't leave the Starship up in orbit, and where it reenters needs to be controlled. Why? Plenty of boosters re-enter uncontrolled and burn up all the time.

Stated simply: zero-thrust "orbits" repeat the same trajectory again and again. So if you end your burn in the outer atmosphere near your launch pad, the next time around you will be back in the outer atmosphere (near where the the launch pad "was", ignoring the rotation of the planet). And since there's air there providing resistance, you'll re-enter and crash.

Getting to orbit requires at least one more burn near the apogee of the original orbit to circularize it and ensure the spacecraft doesn't approach the atmosphere again. Starship didn't do the apogee burn they intended to do, so didn't demonstrate this capability.

Re: Starship's Third Flight Test [video]

#175

Post by tempaway444641 »

pixl97 wrote: post #116
tempaway444641 wrote: post #88

T+37: Seems a little turny-aroundy in orbit there and a bit "small-pieces-falling-offy" Still, good job getting it there T+43: seems to be turning around a bit too much for something thats got heat shields on one side and is about to re-enter T+45: flaps moved, maybe that is supposed to get it the right way round, I get it now - it uses the flaps to orient for re-entry T+46: the little bits of debris must be tiles co…

>T+46: the little bits of debris must be tiles coming off Seemed like ice to me, which itself can be it a problem. The vehicle didn't seem very stable even before this point so I'm wondering if we're getting ice build up on the cold gas thrusters which changed the control dynamics keeping the ship from flying stably.

Yeah could be. Some of the debris looked very specific in shape though. On some shots of starship you can see missing tiles (not many though)

Re: Starship's Third Flight Test [video]

#176

Post by terramex »

DarmokJalad1701 wrote: post #167
Laremere wrote: post #148

Earlier quoted context omitted.

Parent's (correct) point is that it isn't a matter of the ascent trajectory. They can't leave the Starship up in orbit, and where it reenters needs to be controlled.

> They can't leave the Starship up in orbit, and where it reenters needs to be controlled. Why? Plenty of boosters re-enter uncontrolled and burn up all the time.

Non-reusable boosters don't go into orbit and perform calculated crash into ocean soon after launch.

Small second stages and spacecrafts can be allowed uncontrolled orbital reentries because they usually burn-up. Starship is too big for that, debris would rain like when Space Shuttle Columbia disintegrated over land. They most likely will need to show engine relight capability to control reentry point before going orbital.

Re: Starship's Third Flight Test [video]

#178

Post by bell-cot »

travisgriggs wrote: post #126
DarmokJalad1701 wrote: post #80

The test is essentially a success at this point. Starship can take payload to orbit and open/close the payload doors. The remaining things are icing on the cake. They can refine re-usability while flying payloads.

I wouldn’t classify the re-entry survival problem as icing. But otherwise, I agree with you.

If their cost per kg to orbit, with total loss of both Booster and Starship, is substantially lower than any of their competitors - then it is success, and recovery is just icing on their profit margins. Er, cake.

(And would be very cool marketing and PR, obviously. Not that SpaceX has much need for either of those.)

Re: Starship's Third Flight Test [video]

#179

Post by cryptonector »

TMWNN wrote: post #153
wongarsu wrote: post #144

Earlier quoted context omitted.

They have a great pipeline for building ships. They want reusability, but for near-term needs like deploying bigger Starlink satellites and their moon lander contract they could probably power through without reentry survival. It would be expensive, but unlike in-orbit refueling not really mission critical

My understanding is that Starship is financially comparable to Falcon 9 on a per-payload basis even if fully expended.

If so that would be amazing.

Re: Starship's Third Flight Test [video]

#180

Post by Toutouxc »

DarmokJalad1701 wrote: post #167
Laremere wrote: post #148

Earlier quoted context omitted.

Parent's (correct) point is that it isn't a matter of the ascent trajectory. They can't leave the Starship up in orbit, and where it reenters needs to be controlled.

> They can't leave the Starship up in orbit, and where it reenters needs to be controlled. Why? Plenty of boosters re-enter uncontrolled and burn up all the time.

First thing that comes to mind: Starship has a lot of protection against burning up, so huge chunks of it could survive and cause damage.
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