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Comment by aphextron | Hacker News Reader

I just don't see how this thing will ever carry humans. They can get to the point where it is perfectly nailing 100/100 landings every time without fail and it still wont be safe. One single gust of wind at the wrong time, and everyone is dead. No go-arounds, no ejection system, no aerodynamic ability to correct. Starship can potentially revolutionize cargo access to space, but there's nothing in the history of aerospace travel even remotely comparable to the level of risk this would be taking on.

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Nothing is perfectly safe and space flight was never even close to perfectly safe.

State of the art right now is capsules that rely on parachutes that have no go-arounds, no ejection seats and no aerodynamic ability to correct.

edit: And the Space Shuttle which had go-around and aerodynamic ability to correct was even LESS safe than capsules.

Space Shuttle had no go around after the deorbit burn - you either land on the runway or ditch somewhere close to it (and ditching is kinda hard to do when landing not on the Cape but in the New Mexico desert).

Unlike the Soviet Buran Shuttle, there was no option to install an auxiliary jet engine and you had to be a very good pilot to compensate for the Shuttles brick like gliding qualities.

The space shuttle didn't have go-arounds; it was an unpowered landing, so they had to nail it the first try.

Starship actually _could_ have go-arounds, depending on how much fuel margin they have available.

> but there's nothing in the history of aerospace travel even remotely comparable to the level of risk this would be taking on

The space shuttle?

>The space shuttle?

The space shuttle landed aerodynamically. Starship would be taking on the same risk profile of a launch system with no escape mechanism, and reentry based on ablative tiles, without the one redeeming feature the shuttle did have which is the ability to control its' own descent unpowered and select a suitable landing site.

Once you deorbit you select between one target landing strip and lithobraking.

Starship could conceivably land on anything reasonably flat if it needs to land in an emergency compared to Super long special runway the Shuttle needed.

They said if a human went over 40mph they would be torn apart, when locomotives were invented and I'm sure there were similar comments about the Wright Brother's at the time they showed the world their crazy invention that would never be able to carry humans safely.

No way in hell a single gust of wind is going to be a problem - this thing is HEAVY even at landing and even then the raptors are powerful enough to not just slow it down to effectively hover but also flip it from horizontal to vertical in seconds. Unless you are insane enough to land into a Typhoon wind should not be a problem at all.

Yes, it's unlikely that SpaceX will use the flip maneuver for humans any time soon.

I believe they can just burn extra fuel margin to do a traditional vertical landing though. It costs payload, but it should be doable.

When maximizing cargo delivery to the surface of Mars, I'm sure they'll always do the flip.

Assuming they have enough fuel margin they could probably just fly back up a few meters and try again in the rare case of an unexpected event causing an imperfect landing approach. Doesn't seem much worse than a helicopter in that regard.

I agree it'll probably be quite a while before they reach that level of safety though. This is brand new technology, and it's not going to reach the level of reliability of traditional aircraft without decades of experience with different failure modes and techniques for mitigating them.

The space shuttle had no escape mechanism, and they also did no substantial unmanned testing.

The shuttle also killed more people in spaceflight than any other space vehicle in history: https://en.wikipedia.org/wiki/List_of_spaceflight-related_ac...

What's the ratio of killed people to transported people?

2 total failures, 135 flights, so 1 in 67 flights resulted in everyone dying.

By contrast you have a fatal airplane crash in the order of 10,000,000s flights.

The rate of 1/10,000,000 is for commercial regular aviation. Private fights have a much larger rate, usually even larger than 1/1,000,000, what is a normal rate for civilian transportation (a few times more or less).

Space fight is a lot more dangerous than normal in-planet transportation, and the Space Shuttle is on the more risk side of it (but any project has too small numbers to generalize).

... after a century of development

given the inherent danger of space travel, I don't think the risk will ever meet parity with air travel.

Planes glide, and are generally only unsafe during a few critical moments after tire-lift.

Planes that don't glide are generally considered unsafe and highly specialized.

I fail to wrap my head around how a mechanism that uses active propulsion for all phases of flight could ever match the safety of a mechanism that exploits passive physics in the face of active propulsion system-failure.

That said, I couldn't tell you how to achieve space-flight otherwise except for maybe a shuttle-lander type system -- I am simply stating that the comparison of risk between air travel and space travel seems absurd to me.

Of course space travel would be more dangerous.

Everything is harder or more dangerous that's not been done. Otherwsie it would have been already, right?

I get your point but things become normalised over time and mechanisms/technology invented to deal with the risk and conditions. If you'd said to people 150 years ago that there would be (well pre-covid days) at any one time about a million people at 30k feet flying around in basically a tin can, journeying across the world in a day, they'd say you're mad and it's too dangerous to achieve. They didn't have the technology capable, like a jet engine or fabrication techniques. Maybe in 50 years we do have a new technology that meets the crtieria needed, maybe not, but the same happened before and I'm sure it'll happen again.

"Modern rockets originated in 1926 when Goddard attached a supersonic (de Laval) nozzle to a high pressure combustion chamber"

So, rockets have had almost a century of development too. You could even stretch that and claim more like 6-700 years, as the Chinese had "one of the world's earliest multistage rockets and ballistic cruise missiles" around the 14th century: https://en.wikipedia.org/wiki/Huolongchushui

+ both space shuttle crashes should not have happened. There were people involved in both circumstances ringing the alarm bell and warning of the likelihood of the outcome. Those were not failure of technology, they were failure of culture and courage (though in the case of Columbia, I'm not sure what the rescue plan would have been).

Since the moon lander version has high-mounted Dracos to touch down without kicking up dust, would it be possible for Earth Starship to incorporate a similar design as a backup landing system?

You'd need substantially more of them in Earth's gravity, and they're not going to save you from an explosion unless you make the crew capsule detachable.

The flip-and-land maneuver doesn't permit much "uh oh, it's gone wrong..." time to correct, either. I think they're going to have to go more in the direction of airliner-style "look, things kinda have to work" - there's no ejection seat, no parachute.

I'm pretty sure this design is to re-use unmanned launch hardware only.

If humans were involved in the landing I think the design would be significantly different.

I take it that it's specifically the 'flip' that is concerning you here?

From this latest test, it looked like SpaceX shared the concern, and took steps to address it. It was less "last-second hover-slam" and more "we'll flip, hover, and touch down gently".

With production legs instead of the tiny stubby test ones, I suspect it'd have worked.

It appears the fire that led to explosion was caused by a valve that started leaking even prior to touchdown. i.e. unrelated to the leg failure.

Even better, although it was still visibly leaning after touchdown. Not sure what their timeframe is on the new legs.

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