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Starship Flight 5: Launch and booster catch [video]

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Re: Starship Flight 5: Launch and booster catch [video]

#621

Post by ceejayoz »

supportengineer wrote: post #597
robotnikman wrote: post #588

The engineers at spaceX are amazing, and I'll admit I envy their tenacity and genius. The amount of progress we have seen in rocketry and space travel in the last decade is mind blowing, I never thought I would see this in my lifetime. Edit: Decided to give it a shot and applied for a backend software engineering position at SpaceX. I'm not sure if it will be noticed, but its worth a shot. I may not be a rocket scien…

We could have had this all along.

Eh, maybe. There’s a lot of computing and telemetry going on that benefits from the last twenty years of miniaturization and performance. The iPhone seemed impossible when announced to BlackBerry; tech has gone crazy fast.

Re: Starship Flight 5: Launch and booster catch [video]

#622

Post by m4rtink »

dmitshur wrote: post #320
autonomousErwin wrote: post #197

Earlier quoted context omitted.

I always thought the liquid sloshing would be one of the hardest to simulate (considering how chaotic fluid mechanics is). Interestingly, I think this caused the 2nd Falcon launch to fail (the LOX sloshing).

Has it been considered to spin the fuel via some centrifuge mechanism as a way to remove sloshing from the equation, or is that more complex/expensive/error-prone than just predicting it via simulation?

I'm thinking we will eventually end up with "active fuel management" techniques like this for in space vehicles.

Bug tanks make sense there & they might not be always full. So I can imagine all kind of interesting ways you can work with the fuel in zero go to avoid not only slosh but also the need for ullage thrusters. Eq. some programmable nozzles using in-tank gas to nudge liquid fuel blobs to move in the right direction. Or even some nets or bags that herd in the fuel in the middle of the tank + prevent it from directly touching the side, reducing boil-off or refrigeration requirements. :)

Re: Starship Flight 5: Launch and booster catch [video]

#624

Post by davedx »

wolf550e wrote: post #454
h2odragon wrote: post #177

My wife asked "Why is this a big deal?", so I gave her a link to Handmer's 2021 explanation: https://caseyhandmer.wordpress.com/2021/10/28/starship-is-st... She's not an enthusiast; she's got an impression from SciFi that going to mars shouldn't be that hard.

Robert Zubrin's Mars Direct would have got "flags and footprints" on Mars without needing something like Starship. He worked on a version of SLS in 1989 in Martin Marietta that would have cost $1B and been ready in the second half of the 90s and would be retiring soon after many successful flight to Mars (and to the Moon), but instead we got SLS and Orion so we need Starship to get anything done.

The Mars Direct book is worth reading not only for things like transport and mission design but also a wealth of other good ideas about how to “live off the land” when we get there too. Truly worth reading for anyone remotely interested in space exploration

Re: Starship Flight 5: Launch and booster catch [video]

#625

Post by mensetmanusman »

erikerikson wrote: post #492
dtquad wrote: post #183

Earlier quoted context omitted.

MIMO and nonlinear control theories are probably some of the hardest topics in all of engineering. SpaceX control system also has to compensate for the fuel moving inside their rockets so the control algorithms probably involve some kind of fast numerical fluid simulation. Another interesting thing SpaceX is doing is to use consumer-grade chips in triple redundancy configurations instead of using $100,000+ radiation-…

I have been told by people who worked on them that you get radiation hardened aerospace/defence grade chips by backing off the clock speed about 20% to give signal stabilization slightly longer time. I can understand the population being confused about this but industry being confused seems to have more to do with regulatory capture and beaurocratic moats which SpaceX does seem to be bypassing.

You also have to add massive amounts (relatively) of static sink by approaches like ‘silicon on insulator’ to prevent energetic electrons from hopping into the transistor layer.

Re: Starship Flight 5: Launch and booster catch [video]

#626

Post by iamcreasy »

cryptonector wrote: post #581
ro_bit wrote: post #520

The catch looks amazing, but one thing I don't understand is why SpaceX needs the technology to catch a booster they've already demonstrated the ability to land boosters on barges. Is the arm more cost effective to scale compared to a barge?

Weight. Legs weigh a lot. That's dead weight for a launch system, and it serves only to reduce payload to orbit. For Falcon 9 that's not that big a deal because they're NOT trying to reuse the second stage. Whereas with Starship they need more fuel to recover the ship, and that means they need to save weight elsewhere to avoid losing too much payload to orbit.

SpaceX is also not very happy with the pair of forward flaps and 10 ton thermal protection needed as control surface and re-entry.

Re: Starship Flight 5: Launch and booster catch [video]

#627

Post by bluescrn »

FrustratedMonky wrote: post #598
dang wrote: post #506

[stub for offtopicness]

[flagged]

SpaceX is not Musk. It may be executing his vision, but it's a team of thousands of skilled and hard-working people, all eager to work on a Sunday for a chance to pull something like this off.

Re: Starship Flight 5: Launch and booster catch [video]

#628

Post by le-mark »

roca wrote: post #611
FrustratedMonky wrote: post #598

Earlier quoted context omitted.

[flagged]

Both. A single person can be great in some areas and a malicious loon in others. In fact, great success in one field can provide the self-confidence and capital to be a catastrophe in others. But also keep in mind that Musk isn't personally designing and building everything SpaceX does. The staff at SpaceX deserve more credit than they get, especially Gwynne Shotwell.

That is true, but it’s also true of Blue Origin who are far behind spacex in so far as flying real hardware. The difference is Musk maniacal zeal and yes leadership. I’m frustrated with Musks politics too, but his drive can’t be denied.
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