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49 minutes ago, mikegarrison said:

(It's more usual to compare accident rates per passenger-mile or passenger-km rather than trips.)

Trips makes more sense for this comparison, doesn't matter how far you hop, every other engine start needs to happen or BOOM.

The short answer is that SS as a crew vehicle is a long way off, IMO, or at the very least many flights in a row with no failures (hundreds for commercial crew level safety, dunno, millions for airline level?)

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58 minutes ago, mikegarrison said:

(It's more usual to compare accident rates per passenger-mile or passenger-km rather than trips.)

I suppose it's not really useful for space travel though, unless we're talking stuff like the pressurized compartment or the electrical system etc.

For the engines and the manoeuvres it's more useful to count it against the number of occurrences it happens.

8 minutes ago, tater said:

The short answer is that SS as a crew vehicle is a long way off, IMO, or at the very least many flights in a row with no failures (hundreds for commercial crew level safety, dunno, millions for airline level?)

Airplane-level seems to need like another decade or more...

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27 minutes ago, YNM said:

Airplane-level seems to need like another decade or more...

At least, lol.

Airline travel is about the safest thing people can do right now. Not only are crashes rare, they are almost always pilot error when they do happen.

Commercial crew has a LOC event requirement of 1:270.

Presumably SpaceX could fly their way to that sort of rating with a combination of engine start data, and actual flights/landings at some value below 270 flights. It seems.... sketchy, regardless of the math, however. Spaceship 2 might be every bit as safe as New Shepard's capsule based on the calcs, but I'd get on New Shepard if given a free ride, but I'm not sure I'd ever trust Spaceship 2. I'd think in any sort of shot to medium term use as a crew vehicle I'd want a robust LES for Starship. There's not a reason to put huge numbers of crew on any spacecraft yet. Even 10-20 people would be a really large crew for any plausible use case for current space programs with a good lunar base established. Seems like they could "waste" cargo capacity on a crew vehicle and have the top separate taking all 10-20 crew.

Actually, a crew vehicle is a different thing than cargo/tanker. Cargo is empty coming back, hence the LOX tank in the nose.

The crew version will have a lot of heavy stuff that stays in the nose all the time, and won't need the header tank there. It will have all the life support hardware, plus consumables. With a payload of 100-150t to LEO, and a crew compartment that is mostly empty space, they will actually need to ballast the crew area if anything to get close to 100t in the nose. Adding a capsule with solid motors to pull it off would make a lot of sense early on.

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4 hours ago, mikegarrison said:

If there were only a 99% chance of avoiding injury in a car trip, there would be 11,000,000 injury accidents in the US every day. 99% is completely unacceptable.

Well, spaceflight is not driving a car and will obviously never (or at least for a VERY long time) be as safe as driving a car. 99% might be unacceptable for manned flights but comparing it to car trips is pretty dumb.

Exploration has always been quite dangerous and required big risks to be taken.

Edited by tseitsei89
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21 minutes ago, tseitsei89 said:

Well, spaceflight is not driving a car and will obviously never (or at least for a VERY long time) be as safe as driving a car. 99% might be unacceptable for manned flights but comparing it to car trips is pretty dumb.

Exploration has always been quite dangerous and required big risks to be taken.

There are 2-3 different use cases being discussed here for Starship. Comparing it to car trips is not dumb at all, it depends on the use.

1. Crew flights per NASA guidelines. Assuming they have to meet Commercial Crew standards at the very least, that's a standard of one Loss of Crew incident every 270 flights. That's 99.6%.

2. Crew flights to Mars. This is goofy for the time being, but it's SpaceX's internal goal. The risk to life and limb might be greater than commercial crew (<cough> Donner Party <cough>) even without spacecraft failures, dunno for that.

3. Point to point transport on Earth. SpaceX has discussed this, and this needs to be airline safe to be a thing, which is 1 fatal crash every 3,700,000 flights (99.99997% safe).

Apparently 99.885% safe is really terrifying to people.

Edited by tater
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1 hour ago, tater said:

1. Crew flights per NASA guidelines. Assuming they have to meet Commercial Crew standards at the very least, that's a standard of one Loss of Crew incident every 270 flights. That's 99.6%.

Yeah well, obviously 99.6% would be completely unacceptable for a car trip safety as well. But as I said: spaceflight is not and will not be like driving a car.

 

1 hour ago, tater said:

2. Crew flights to Mars. This is goofy for the time being, but it's SpaceX's internal goal. The risk to life and limb might be greater than commercial crew (<cough> Donner Party <cough>) even without spacecraft failures, dunno for that.

0.5% or even 1% chance of death during landing seems quite irrelevant in the grand scheme of things here to me. You are probably much more likely to die of some other cause when trying to live on Mars than that 1%.

 

1 hour ago, tater said:

3. Point to point transport on Earth. SpaceX has discussed this, and this needs to be airline safe to be a thing, which is 1 fatal crash every 3,700,000 flights (99.99997% safe).

 

Possible point to point transportation of starship is still FAR FAR away in the future (even compared to starships possible crewed spaceflights and going to mars) and I doubt it will never even happen. It would need amazing safety margins and it would still probably be really expensive compared to airplanes. Fast of course but you can already fly across atlantic in less than a day.

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While I still keep treating the SpaceX interplanetary plans as nonsense, first of all because they look suicidally,
it's a time to bring again the statistics of the mor.... mortuary of the heroes climbing the highest mountains

https://www.bbc.com/news/world-47418215#:~:text=Everest deaths,has fallen to below 1%.

Spoiler

816

 

So, LES  is optional.

1. They don't prohibit the suicidal climbing on mountains.

2. A mountain is a "high ground".

3. Mars and Moon are a "high ground", too. Very high, up to 2.5 AU high for Mars.

4. They are outstandingly high ground. But still a ground. Say, Jupiter isn't.

5. They will register their Martian trip in the alpinist association as (idk how it's called), not in FAA, NASA, or else.
as
"To climb on an outstandingly high ground, using an atmospheric taxi at the very foot, and as a camp tent during the rest part of the trip."
(That's a truth, they will switch off the engines right near the Earth, far from top,, then just be floating).

6. After getting to the Mars, they plant a flag somewhere, and nobody can't say that they are not alpinists.

So, the SpaceX should start registering the Mars as a part of the Earth, separated by air mass.
(Say, as a remote part of Antarctica, just to avoid undesired arguing).

Upd.

A. SpaceX says the Starship is an intercontinental atmospheric  taxi. Coincidence? I don't think so.

B. Mars and Moons can be declared Antarctic mountains. No definition of "mountain" makes it to be non-spherical. So, two spherical mountains in Antarctica.

Edited by kerbiloid
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Mountain climbing and space travel actually have very few similarities, as far as I can tell. (I have climbed mountains. I have not travelled in space.)

One thing that is perhaps relevant here is that climbers are generally very much in control of their risk. This is unlike being a passenger in a plane, and more like being the pilot of the plane.

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17 minutes ago, mikegarrison said:

Mountain climbing and space travel actually have very few similarities, as far as I can tell. (I have climbed mountains. I have not travelled in space.)

Ditto, albeit mine have not been terribly technical, only a few roped highly exposed sections on mountains that were otherwise scrambles (or top roping in a few locations around the state).

17 minutes ago, mikegarrison said:

One thing that is perhaps relevant here is that climbers are generally very much in control of their risk. This is unlike being a passenger in a plane, and more like being the pilot of the plane.

Yeah, though climbing deaths are probably heavily weighted to "climber error," there are more random ways to die climbing, which is maybe more like equipment failure deaths in spaceflight.

Climbing errors tend to be lag events, too. The error was deciding to climb that day, or to keep climbing instead of turning around, not so much a technical error like you might see flying. The latter is maybe just more acute, you fail to notice what is actually happening with the aircraft, and fly it into the ground (that Air France flight over the south Atlantic thinking they stalled because the pitot tube ice resulted in them being told that—in spite of the other instruments showing normal flight).

For passengers in the "tourist" sense, spaceflight needs to be pretty safe for there to be a market. It might not have to be modern airline safe, but at least 1960s airline safe probably.

Most people have zero ability to realistically assess risk. Spaceflight risk could be at about the same population level as "accidental death" separated from car deaths (~46:100,000) and they'd want to stay home (auto deaths are ~11:100k). As a result, I think it has to be insanely safe for there to be any chance of acceptance.

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2 hours ago, kerbiloid said:

I see. Up to 25%  deaths per success.

You're talking about 8000m peaks as if all climbing is the same. You might as well suggest that wingwalking is the same level of risk as flying commercial. Or that going to Mars is the same level of risk as riding a New Shepard.

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10 minutes ago, StrandedonEarth said:

An easy way to say "We landed on Deimos!"

Not that it's so hard to land on Deimos anyway...the real trick is keeping from flying off again.

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2 hours ago, cubinator said:

Would you really want your gateway to another world to be named after a god of dread, though?

It perfectly describes the passenger emotions during the launch.
Another vessel should be Phobos.

***

But when they start flying to Pluto, they'll call their boat Charon.

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48 minutes ago, Ultimate Steve said:

Why is wind a constraint for a static fire?

The man-lifts they use to work on Starship have a maximum safe wind speed. If they can't use those, static fire prep can't happen.

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