willow_hiller
Well-Known Member
Elon confirms shutdowns were intentional, and it reached the planned apogee: https://twitter.com/elonmusk/status/1336818987389181952?s=19
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
e-FTW
New electron smell
DanCar
Active Member
Elon said low fuel pressure caused the landing fail.
https://twitter.com/elonmusk/status/1336809767574982658
https://twitter.com/elonmusk/status/1336809767574982658
e-FTW
New electron smell
Good:
1. Control during ascent (very stable)
2. Control during fall (very stable)
Bad:
3. Multiple engines eat themselves on landing (green exhaust == really bad)
We haven't even gotten to the difficult stuff yet:
4. Reentry heat-shielding and control
5. Multiple refueling launches to accomplish anything BEO
6. Landing on unprepared surfaces (engines, legs, etc)
I think #6 can be solved with enough mass but #4 and #5 will be killers. Item #5 is the Achilles heel of SS/SH.
1. Control during ascent (very stable)
2. Control during fall (very stable)
Bad:
3. Multiple engines eat themselves on landing (green exhaust == really bad)
We haven't even gotten to the difficult stuff yet:
4. Reentry heat-shielding and control
5. Multiple refueling launches to accomplish anything BEO
6. Landing on unprepared surfaces (engines, legs, etc)
I think #6 can be solved with enough mass but #4 and #5 will be killers. Item #5 is the Achilles heel of SS/SH.
Xepa777
Banned
Remarkable. Today was the day we learned that we could be a multiplanetary species.
That was absolutely incredible to watch. Already watched it a few times. I was in awe when it flipped and came down for a landing. Dang and on the landing pad too!
One commentor on YT mentioned Flash Gordon and gosh yes I remember watching his ship flying through air and it was kind of deja vu but in color and in reality really happening.
One commentor on YT mentioned Flash Gordon and gosh yes I remember watching his ship flying through air and it was kind of deja vu but in color and in reality really happening.
It is both steering/ attitude control and reducing teminal velocity. It's more like a skydiver than a glider.
@willow_hiller check out the replay during the bellyflop sequence and you'll see the control surfaces constantly trimming to maintain attitude, very much like a skydiver does with their hands.
MartinAustin
Active Member
It is to allow for slowing down when you get to a planet with an atmosphere. (the obvious one being Mars). Little to no energy is used to slow the rocket down. There are no drag parachutes. No rockets are fired. You basically slow down for free and then are able to use a little bit of rocket fuel to land the rocket at the end.
I would say the Space Shuttle used a similar technique, melded with aerodynamic gliding, for the same purpose.
The reason engines were eating themselves is because they didn't get the tank pressures right, so the engines weren't getting the right amount of propellant/oxidizer. Relatively easy fix now that they have the data. I mean, this is the first time anyone has put a rocket in a horizontal configuration ahead of a relight before, so something had to not quite go right.
And the reason it crashed is because it was coming down too fast because the engines weren't getting enough propellant/oxidizer.
The interesting thing to me was how slow the ship fell once it was in a horizontal configuration. I mean, that makes sense. The ship has a huge cross area thus the terminal velocity won't be very high. Making such a ship fall as stable as it did, especially considering you had liquid fuel sloshing around inside was very impressive. As were the high precision maneuvers to re-orient the ship to a landing position.
Yes, re-entry heat shielding is an issue, but why aren't you believing SpaceX has it solved, or mostly on their way to solving it? We aren't that far away from the super heavy booster being ready for testing which means a re-entry test won't be far behind.
Oh the things the kids today will see in their lifetime!
How much is heat shield different from what the Falcon goes through? Yes, it's nowhere near orbital velocity, but it is pretty damn fast and still does not heat up (because it retro-fires to slow horizontal speed, among other things). Shuttle and capsules need big heat shields because they lose the 17,000mph using wind resistance (causing serious heat). Presumably if some of that velocity can be bled off with rockets before hitting the atmosphere, then the heat problem is a lot smaller.
Similar threads
- Article
