4 ms·

SN10 (Starship) High-Altitude Flight Test

31 points by bpierre 6y ago

deleted 6y ago
[deleted]
ipnon 6y ago
Going to Mars is slowly changing from insane to possible to likely.
dkarp 6y ago
And it was a success!
Gehinnn 6y ago
This inspires me.
Cu3PO42 6y ago
The absolute mad lads did it. Personally, I always thought "this seems a lot hard than it has to be" about this landing maneuver [1], but here we are. At this point I'm quite certain they're going to iron out the kinks and will be able to get this consistently right soon enough. [1] Starship basically does a belly flop to slow down and only flips to an upright position just before landing.
AareyBaba 6y ago
Can someone explain why the belly flop is necessary. Couldn't the slowing down by air resistance be done using the engine thrust in a vertical position instead ?
- jiggawatts 6y ago
  The tyranny of the rocket equation. Every kilogram matters, because to lift that kilogram you need even more kilograms of fuel, but to lift that fuel you also need some more fuel! It's brutal. So you save and you cut and you leave out everything that isn't absolutely necessary. Air resistance is almost free. You do need control surfaces, but they're small and hollow flaps. Fuel is heavy. That's why 100% of spaceships use aerobraking during reentry. It's much, much cheaper than any kind of sci-fi powered descent.
  - nickik 6y ago
    Everyday Astronaut will soon release a video with all the math about this. It turns out that even doing the flip slightly higher, already has a massive impact in terms of energy required. Slowing down from Orbital speed is an insane amount of energy that has to be removed. You really only want the last tiny bit to be removed by rocket thrusting.
- raphaelj 6y ago
  Are they planning to use the same ships to land on Mars and on the Moon ? You'll not be able to slow down (as much) using air resistance there.
antiquark 6y ago
They forgot the part where it later exploded on the landing pad. https://www.youtube.com/watch?v=HECTypGUfQE https://www.youtube.com/watch?v=HECTypGUfQE
jiggawatts 6y ago
One thing that struck me as a bit odd about the starship tests is that they always look like they're on fire, which is unexpected since they're almost entirely stainless steel construction. There doesn't seem to be any flammable material acting as a fuel source! So... what's burning!?
- nickik 6y ago
  There are a lot of different things that potentially can be going on. We had a couple things burn in the engine bay in the last couple test. What you are referring to however is most likely related to access gas. Starship starts up 3 engines, and then shuts down two of them to land with 1 engine. Both during the startup and but most shutdown, some amount of access methane escape from the engine. Since the other engine is still burning and hot, this access gas can start to burn. This is not all that concerning most of the time as long as there is not a continual leak.

31 points by bpierre 6y ago

deleted 6y ago

[deleted]

ipnon 6y ago

Going to Mars is slowly changing from insane to possible to likely.

dkarp 6y ago

And it was a success!

Gehinnn 6y ago

This inspires me.

Cu3PO42 6y ago

The absolute mad lads did it. Personally, I always thought "this seems a lot hard than it has to be" about this landing maneuver [1], but here we are. At this point I'm quite certain they're going to iron out the kinks and will be able to get this consistently right soon enough. [1] Starship basically does a belly flop to slow down and only flips to an upright position just before landing.

AareyBaba 6y ago

Can someone explain why the belly flop is necessary. Couldn't the slowing down by air resistance be done using the engine thrust in a vertical position instead ?

jiggawatts 6y ago
The tyranny of the rocket equation. Every kilogram matters, because to lift that kilogram you need even more kilograms of fuel, but to lift that fuel you also need some more fuel! It's brutal. So you save and you cut and you leave out everything that isn't absolutely necessary. Air resistance is almost free. You do need control surfaces, but they're small and hollow flaps. Fuel is heavy. That's why 100% of spaceships use aerobraking during reentry. It's much, much cheaper than any kind of sci-fi powered descent.
- nickik 6y ago
  Everyday Astronaut will soon release a video with all the math about this. It turns out that even doing the flip slightly higher, already has a massive impact in terms of energy required. Slowing down from Orbital speed is an insane amount of energy that has to be removed. You really only want the last tiny bit to be removed by rocket thrusting.
raphaelj 6y ago
Are they planning to use the same ships to land on Mars and on the Moon ? You'll not be able to slow down (as much) using air resistance there.

antiquark 6y ago

They forgot the part where it later exploded on the landing pad. https://www.youtube.com/watch?v=HECTypGUfQE https://www.youtube.com/watch?v=HECTypGUfQE

jiggawatts 6y ago

One thing that struck me as a bit odd about the starship tests is that they always look like they're on fire, which is unexpected since they're almost entirely stainless steel construction. There doesn't seem to be any flammable material acting as a fuel source! So... what's burning!?

nickik 6y ago
There are a lot of different things that potentially can be going on. We had a couple things burn in the engine bay in the last couple test. What you are referring to however is most likely related to access gas. Starship starts up 3 engines, and then shuts down two of them to land with 1 engine. Both during the startup and but most shutdown, some amount of access methane escape from the engine. Since the other engine is still burning and hot, this access gas can start to burn. This is not all that concerning most of the time as long as there is not a continual leak.