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Super Heavy has splashed down in The Gulf of Mexico

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Re: Super Heavy has splashed down in The Gulf of Mexico

#261

Post by HPsquared »

krapp wrote: post #147
madaxe_again wrote: post #95

Earlier quoted context omitted.

Those 10k+ people would all be doing something different if it weren’t for that one guy - so ultimately, yes.

How do you know? It's entirely feasible someone other than Elon Musk could have founded a similar company with similar goals, the same or equivalent competent staff, and had the same success. There is no unique magic sauce that Elon brings to the table here, other than money.

Depends on your opinion on the "Great Man Theory of History". https://en.m.wikipedia.org/wiki/Great_man_theory

Re: Super Heavy has splashed down in The Gulf of Mexico

#262

Post by dividedbyzero »

> SpaceX won a multibillion-dollar contract from the agency to use Starship as a crewed lunar lander as part of NASA's Artemis moon program

So four people would arrive at Lunar orbit in an Orion, board a huge prepositioned Starship, and fly that down to the surface?

Re: Super Heavy has splashed down in The Gulf of Mexico

#264

Post by notact »

bagels wrote: post #251
notact wrote: post #250

Earlier quoted context omitted.

I understand the atmosphere is used to slow the vehicle - it's basically free brakes that you don't have to carry with you. I never suggested using rockets in reverse to slow the vehicle down. What I am asking is, instead of effectively standing on the breaks and generating enormous amounts of friction in a short period of time, why can't the vehicle ease onto the breaks and spread the friction out over time so it ca…

They already use a shallow angle. There's just a lot of energy involved. As soon as the drag kicks in, the angle gets steeper and steeper on its own as the drag slows the craft down.

I guess this sorta makes sense - the slightest slowdown starts to deorbit the vehicle, at which point a particular descent rate becomes difficult to maintain?

Re: Super Heavy has splashed down in The Gulf of Mexico

#265

Post by HPsquared »

mulmen wrote: post #131
Laremere wrote: post #121

Earlier quoted context omitted.

The other external view we got was mounted on one of the other flaps, and we didn't get footage from it even after the camera we did get was obscured. So some amount of damage/overheating on multiple fins is likely.

I was wondering how much video bandwidth they have. Do they have all angles streaming all the time and they switch in the booth or can they only capture one video feed at a time? With that fin melting they may have just elected to stay focused on it.

I don't know how they had any communications at all, doesn't the plasma surrounding the craft act as a Faraday cage?

Edit: supposedly the Space Shuttle could also communicate with satellites during re-entry. There's a hole in the plasma behind the spacecraft and, Starship being large, must leave a bigger opening for the signals to pass through.

Re: Super Heavy has splashed down in The Gulf of Mexico

#266

Post by baq »

world2vec wrote: post #254

Seeing the Starship's flap visibly burning in the reentry heat and still survive well enough to move around and get to a splashdown was just incredible. Amazing progress in just four test flights.

yeah the thing did a soft splashdown with a leaking flap, the fluid in question being molten stainless steel.

this was hard sci-fi, streamed live for everyone to see.

Re: Super Heavy has splashed down in The Gulf of Mexico

#267

Post by pixl97 »

notact wrote: post #256
bagels wrote: post #247

Earlier quoted context omitted.

It would take a tremendous amount of fuel to do what you're imagining, probably to the point of making the craft impossible to build with current technology. Your orbit would have to be high enough to do a burn to cancel your orbital velocity (lots of fuel), then you have to burn against gravity for a slow vertical descent (lots of fuel). The rocket equation says... you'll need a larger craft and more fuel to carry t…

I'm not sure why people are misunderstanding my question as "Why not bring more fuel and burn the rockets in reverse". I am simply asking: why not reenter the atmosphere at a shallower angle, spreading the atmospheric braking friction over a longer period of time, which I'd expect would allow more time for the accumulated heat to radiate away before it becomes catastrophic.

Gravity is one you are still being pulled down.

The other is at too shallow of angle at high speed you bounce off like skipping a stone off the surface of a lake.

Re: Super Heavy has splashed down in The Gulf of Mexico

#268

Post by mrandish »

notact wrote: post #256
bagels wrote: post #247

Earlier quoted context omitted.

It would take a tremendous amount of fuel to do what you're imagining, probably to the point of making the craft impossible to build with current technology. Your orbit would have to be high enough to do a burn to cancel your orbital velocity (lots of fuel), then you have to burn against gravity for a slow vertical descent (lots of fuel). The rocket equation says... you'll need a larger craft and more fuel to carry t…

I'm not sure why people are misunderstanding my question as "Why not bring more fuel and burn the rockets in reverse". I am simply asking: why not reenter the atmosphere at a shallower angle, spreading the atmospheric braking friction over a longer period of time, which I'd expect would allow more time for the accumulated heat to radiate away before it becomes catastrophic.

I'm no expert but I think reentering at a shallower angle results in "bouncing off" the atmosphere. So, even if you did it multiple times like a rock skipping on water, you'd have to have extra fuel to counter the bounce "up" and go back down for each skip. Thus, back to the same "bring more fuel/weight to orbit" problem.

Re: Super Heavy has splashed down in The Gulf of Mexico

#269

Post by ceejayoz »

HPsquared wrote: post #265
mulmen wrote: post #131

Earlier quoted context omitted.

I was wondering how much video bandwidth they have. Do they have all angles streaming all the time and they switch in the booth or can they only capture one video feed at a time? With that fin melting they may have just elected to stay focused on it.

I don't know how they had any communications at all, doesn't the plasma surrounding the craft act as a Faraday cage? Edit: supposedly the Space Shuttle could also communicate with satellites during re-entry. There's a hole in the plasma behind the spacecraft and, Starship being large, must leave a bigger opening for the signals to pass through.

https://en.wikipedia.org/wiki/Communications_blackout#Spacec...

> Until the creation of the Tracking and Data Relay Satellite System (TDRSS), the Space Shuttle endured a 30-minute blackout. The TDRSS allowed the Shuttle to communicate by relay with a Tracking and Data Relay Satellite during re-entry, through a "hole" in the ionized air envelope at the tail end of the craft, created by the Shuttle's shape.

Starlink's just much higher bandwidth.

Re: Super Heavy has splashed down in The Gulf of Mexico

#270

Post by api »

ryandvm wrote: post #221
api wrote: post #120

Earlier quoted context omitted.

I’ve said for a while that we won’t be ready for the real space age until you can have a rusty pickup in space. What I mean by that is that we have it down well enough that the tech exceeds tolerances and can degrade gracefully. You see this in some sci-fi where there are rust bucket old ships that work.

You have to be careful how much wisdom you glean from fiction. The sheer hostility of space kind of precludes the "she's a good ol' ship" trope. When your door doesn't shut on your pickup, you can bang on it a bit. When your door doesn't shut on your spacecraft, you've got a ship full of corpses that look like a blob fish brought up from the Marianas Trench.

I think the definition of workable old ship is going to be different in space, but ultimately you can expand workable envelope for it by over-engineering critical parts. That's kind of what I mean. Right now we don't quite know how to do that efficiently or effectively.

Still remember that at one time moving faster than 15mph was considered insane and pushed the limits of materials and vehicle design. Same for high altitude flight, McMurdo station, deep ocean diving, etc.

In a lot of ways very deep ocean diving is harder than space. The pressure differentials are a lot worse.

The hard part about space is really launch and delta-V budgets.

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