4 ms·

What I find odd is: when this thing is operational, passengers are supposed to ride through this "flip to land" maneuver?

ianai 6y ago
Well apparently they’re looking into ways to catch the rocket with a landing arm looking platform. Really I think they need to get those engines to fire in any circumstance. But with N=2 it’s hard to know anything.
- jvzr 6y ago
  The catching arm is for the first stage, IIRC Second stage has always been about that flip, be it on the Moon, Mars or Earth
  - _jjkk 6y ago
    No flipping on the Moon since it provides no advantage there (No aerobraking)
    - jvzr 6y ago
      That's a very good point. Looks like my brain also had a major malfunction ;)
- emilecantin 6y ago
  That's for the booster. The goal is to skip landing legs for the booster, as it'll only operate around Earth, so it's "easy" to build infrastructure instead. Starship (the 2nd stage) will always do that flip & land on legs, as it also needs to do it on Mars.
x3n0ph3n3 6y ago
They sure are!
rbanffy 6y ago
I think the suicide burn will be dropped for passenger flights, but the flip is an integral part of the braking maneuver.
- cameronh90 6y ago
  What would they replace it with?
  - le-mark 6y ago
    Seems like there are two different things here; launching passengers and freight, and returning passengers in comfort and without neck injuries. One could easily envision a passenger only winged glider similar to the space shuttle to serve the passenger return role. Indeed, although spacex has nothing like that planned, these BFRs enable damn near anything.
    - bostonsre 6y ago
      Maybe some gyroscopic passenger seats that stay in one position relative to the ground so that they only feel g's going in one direction instead of being rag dolls.
    - natch 6y ago
      The atmosphere on Mars is not as thick as ours so there might be an issue with that winged glider vision. And then there is the moon...
      - m4rtink 6y ago
        Both have much weaker gravity though.
        natch 6y ago
        But that doesn’t help when you have zero atmosphere. Zero times anything is still zero. And doesn’t help enough when the atmosphere is too thin.
jlmorton 6y ago
If I've already signed up to ride a large soda can filled with 4,600 metric tons of cryogenic methane and oxygen into a near-perfect vacuum, only to re-enter the atmosphere at orbital velocity, I suppose I could deal with a flip maneuver.
kimundi 6y ago
The flip will be less extreme in later designs because they will have better/larger RCS control thrusters to rotate it without involving the main engines. Also the center of rotation can be controlled to be inside the passenger section. Add some seats that can automatically tilt 90 degrees and the forces might be barely noticable.

ianai 6y ago

Well apparently they’re looking into ways to catch the rocket with a landing arm looking platform. Really I think they need to get those engines to fire in any circumstance. But with N=2 it’s hard to know anything.

jvzr 6y ago
The catching arm is for the first stage, IIRC Second stage has always been about that flip, be it on the Moon, Mars or Earth
- _jjkk 6y ago
  No flipping on the Moon since it provides no advantage there (No aerobraking)
  - jvzr 6y ago
    That's a very good point. Looks like my brain also had a major malfunction ;)
emilecantin 6y ago
That's for the booster. The goal is to skip landing legs for the booster, as it'll only operate around Earth, so it's "easy" to build infrastructure instead. Starship (the 2nd stage) will always do that flip & land on legs, as it also needs to do it on Mars.

x3n0ph3n3 6y ago

They sure are!

rbanffy 6y ago

I think the suicide burn will be dropped for passenger flights, but the flip is an integral part of the braking maneuver.

cameronh90 6y ago
What would they replace it with?
- le-mark 6y ago
  Seems like there are two different things here; launching passengers and freight, and returning passengers in comfort and without neck injuries. One could easily envision a passenger only winged glider similar to the space shuttle to serve the passenger return role. Indeed, although spacex has nothing like that planned, these BFRs enable damn near anything.
  - bostonsre 6y ago
    Maybe some gyroscopic passenger seats that stay in one position relative to the ground so that they only feel g's going in one direction instead of being rag dolls.
  - natch 6y ago
    The atmosphere on Mars is not as thick as ours so there might be an issue with that winged glider vision. And then there is the moon...
    - m4rtink 6y ago
      Both have much weaker gravity though.
      - natch 6y ago
        But that doesn’t help when you have zero atmosphere. Zero times anything is still zero. And doesn’t help enough when the atmosphere is too thin.

jlmorton 6y ago

If I've already signed up to ride a large soda can filled with 4,600 metric tons of cryogenic methane and oxygen into a near-perfect vacuum, only to re-enter the atmosphere at orbital velocity, I suppose I could deal with a flip maneuver.

kimundi 6y ago

The flip will be less extreme in later designs because they will have better/larger RCS control thrusters to rotate it without involving the main engines. Also the center of rotation can be controlled to be inside the passenger section. Add some seats that can automatically tilt 90 degrees and the forces might be barely noticable.