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Comment by sschueller | Hacker News Reader

I don't see how this is viable the way it lands right now. One failure and you have total loss. With a parachute or wings you can have some failures and still land safely.

Is there going to be an ejection system in case of failure?

EDIT: Instead of just down voting my valid question you could please provide me with an answer so I can understand how such issues are going to be resolved. If the flip maneuver fails I don't want to die.

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But isn't there some redundancy of the parts at least? Of course you can't recover from a failed flip, but having more engines than necessary means some failed ignitions can be tolerated.

There is not sufficient atmosphere on Mars to use either a parachute (not enough drag) or wings (not enough lift), so neither of those options work.

Vertical landing of the rocket seems to be the only rapidly reusable architecture for landing on other planets - the primary purpose of this rocket (eventually).

I'm not sure about other failure handling, you ask a good question and I don't have a great answer. But the mission requirements suggest that vertically landing the rocket is the only feasible landing method I think.

What was the backup for the shuttle?

What was the backup for landing on the moon? What about Mars?

The shuttle has wings, so it doesn't just drop out of the sky.

The moon lander didn't perform a complex flip maneuver.

The moon lander had many complex things, including at the last minute. Remember in space they had to connect up, and separate. Their computer got overloaded when approaching the landing site, and the astronauts had to decide what if anything to do about it. Then they were going to land in a boulder field and the pilot had to take over and go to another place - they had to decide what to do at the last moment. And they almost ran out of fuel before landing (or had little margin left). Each of these things could have lead to loss of the mission.

And neither will Starship when it lands on the moon... it'll do the exact same thing as the LEM. The flip is due to Earth's atmosphere. And there are no runways on Mars, so you can't make a shuttle for it, so you don't have any options left.

I think the current plan with Starship is to not have an abort system, but maybe they'll change their minds between now and when they're ready to start thinking about putting humans on board.

https://everydayastronaut.com/starship-abort/

It only needs one or two of its three engines to land.

I think the flip maneuver is a big issue as it happens near ground and if it fails there is not time to recover irregardless if there are other engines that could perform it.

The flip starts with 3 engines and should work even if 1 of them doesn't start.

It still failed on SN9.

they weren't trying to light all 3 for SN9.

now they light all 3 and turn 2 off when one lights.

So a single failure of a prototype means its never ever ever gone work? What kind of logic is that?

Also you are wrong. SN9 actually used 2 engines for the flip, not 3.

They only swapped to 3 for SN10 and the flipped worked perfectly there. The problem with SN10 was the temporary helium system they put after SN8 in so the engine was ingesting helium.

The point is that you have engine out capability both on the flip and during landing. Of course over time SpaceX need to test some of these profiles in more detail, just as they did for Falcon 9 where they tried various ways of landing.

Of course not. But you can't assume that anything will work 100% of the time. So what will be done if in a rare case the flip maneuver fails? Engines fail but a plane can still land with just one engine. If we are going to be doing intercontinental flights it needs to be as safe as flying.

What happens to a plane if the tail falls off?

What happens if all the engines fail?

What happens if it flies into a mountain?

The Wright Model A crashed, and actually killed someone. That's why aircraft are so unsafe.

They can do the flip at a higher altitude to provide more time for recovery.

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