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SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

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Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#251

Post by dotnet00 »

mjevans wrote: post #200
dotnet00 wrote: post #23

Earlier quoted context omitted.

Probably why they're hoping to get permission for 9 launches this year. Even if they throw away the entire stack, it probably costs less than the equivalent number of F9 launches.

I strongly suspect they'll achieve at least partial re-usability if not full by 9 launches. If not SpaceX will at least have a very clear understanding of the engineering problem by that point. I'm most worried about the final landing which I would not want to be anywhere close to until they've had a solid string of successes without any issues.

I'm not sold on them achieving partial reusability in practice in 9 launches (assuming that the 9 launches happen mainly this year as they have requested). I think they'll have achieved it in theory (ie demonstrated a hover landing of the booster over water), but they've only just started to build out the second tower that'll be needed to actually test reusability without risking the entire launch infrastructure.

Between the construction pauses during testing/launch, and things they can't really speed up like concrete hardening times, I don't think they'll be able to both have 9 flights AND operationalize the second tower this year.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#252

Post by avmich »

bumby wrote: post #246
avmich wrote: post #238

Earlier quoted context omitted.

Engineering, physical principles, I guess. Those who place bets or making predictions may know a thing or two on mechanics, rocket science and history of building launchers.

To put a finer point on it, those seem like rather blunt instruments for prediction compared to how risk is typically measured by aerospace reliability engineers.

I'm sure some aerospace professionals are wondering how it's possible to predict stock behavior on an exchange, but have no problem with educated predictions of launcher performance.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#253

Post by mjevans »

dotnet00 wrote: post #251
mjevans wrote: post #200

Earlier quoted context omitted.

I strongly suspect they'll achieve at least partial re-usability if not full by 9 launches. If not SpaceX will at least have a very clear understanding of the engineering problem by that point. I'm most worried about the final landing which I would not want to be anywhere close to until they've had a solid string of successes without any issues.

I'm not sold on them achieving partial reusability in practice in 9 launches (assuming that the 9 launches happen mainly this year as they have requested). I think they'll have achieved it in theory (ie demonstrated a hover landing of the booster over water), but they've only just started to build out the second tower that'll be needed to actually test reusability without risking the entire launch infrastructure. Bet…

Yes, we solidly agree on the risks associated with an as yet, as far as I know offhand, completely new landing system... Two really strong metal toothpicks.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#254

Post by kelnos »

chasd00 wrote: post #121
RecycledEle wrote: post #82

Earlier quoted context omitted.

Those are big tanks.

yeah and even if starship tanks are perfectly clean you would also have to assume the tanks on the trucks delivering the fuel/oxi are also perfectly clean. As well as storage tanks, plumbing, and everything else.

Unless you filter the fuel as it's pumped into the rocket's tanks.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#256

Post by dotnet00 »

TMWNN wrote: post #236
somenameforme wrote: post #33

Earlier quoted context omitted.

Atlas 5 is already completely obsoleted by the Falcon Heavy which costs about half as much, for a reusable launch, and carries about 3x as much. But for Starship, most people don't seem to realize what a potential game changer this is. The goal for Starship is to get costs down to about 15x less than Falcon Heavy. When you can start sending stuff to space for a few dollars per pound, we're not talking about just prob…

>Atlas 5 is already completely obsoleted by the Falcon Heavy which costs about half as much, for a reusable launch, and carries about 3x as much. Which is why the rocket has been discontinued. This is also why Boeing Starliner is dead man walking. Starliner is only certified for Atlas 5, and there are enough spare boosters for the launches NASA contracted with Boeing for, no more. The consensus is that Boeing will fu…

There is still the possibility of either New Glenn or Vulkan being crew rated to carry Starliner. With Vulkan the concern was mainly that no one was willing to foot the bill, but with the rumored acquisition of ULA by Blue Origin, there's a chance they might want Starliner as their own crew vehicle. The main limitation being that Boeing has already shutdown Starliner production, only making the 2 needed for the ISS contract. So even if anyone else wanted them, they'd have to put in a bunch of money to restart production. Putting all those costs together it might just become better to do something else, e.g. crew rate Dreamliner.

That said, right now it's kind of up in the air, since as it stands, Dragon's second crew contract and Starliner's existing contract are likely to cover all remaining ISS launches. So what's needed afterwards depends on the commercial space stations NASA is pushing for.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#257

Post by margalabargala »

cubefox wrote: post #96
justrealist wrote: post #31

Earlier quoted context omitted.

RUD very often means an anomaly triggered a self-destruct. Saying it "exploded" implies the explosion was not automatically triggered.

I don't think RUD suggests self-destruction. It even suggests the opposite, because having a self-destruction system involved means the explosion wasn't entirely "unscheduled". Indeed, SpaceX describes the lower stage explosion, which wasn't caused by the flight termination system, as a "RUD", but not the upper stage explosion, which was caused by the flight termination system.

I agree with you.

The self-destruction system triggers a RSD.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#258

Post by lmm »

TMWNN wrote: post #239
Sanzig wrote: post #50

Earlier quoted context omitted.

I am pretty skeptical of Starship ever getting used for suborbital transportation, other than maybe for ultra-elite VIP transport or something like a rapid deployment system for military special forces. It seems highly unlikely they will ever get the price down to where it can compete with commercial airliners, and Concorde's commercial failure showed us that people will happily choose cheap subsonic flight over fast…

>Concorde's commercial failure I thought Concorde failed commercially because it couldn't get approval to fly over the US elsewhere over land because of sonic booms. I know reentering spacecraft cause sonic booms but thought that they occur high enough to not cause the same problems on the ground.

> I thought Concorde failed commercially because it couldn't get approval to fly over the US elsewhere over land because of sonic booms.

Or, if you're more cynical, because the US' own supersonic airliner failed and they wouldn't let those Euros show them up.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#259

Post by Gare »

sebzim4500 wrote: post #109
lupusreal wrote: post #89

Earlier quoted context omitted.

I don't think there are many cities that have suitable launch sites near them. It's unlikely they'll ever get approval to launch over populated areas, or even from most populated coastal locations. Also, the issue of getting boosters to all of these destinations seems like a problem. Planes don't split in two and have half return to the launch site but Starships do. So you could land the upper stage in Tokyo, but the…

You'd probably have to launch from international waters, after taking a boat/helicopter. >Also, the issue of getting boosters to all of these destinations seems like a problem You launch them, presumably.

Or just ship them... with a ship.

Re: SpaceX discloses cause of Starship anomalies as it clears an FAA hurdle

#260

Post by dghlsakjg »

misiti3780 wrote: post #44
somenameforme wrote: post #33

Earlier quoted context omitted.

Atlas 5 is already completely obsoleted by the Falcon Heavy which costs about half as much, for a reusable launch, and carries about 3x as much. But for Starship, most people don't seem to realize what a potential game changer this is. The goal for Starship is to get costs down to about 15x less than Falcon Heavy. When you can start sending stuff to space for a few dollars per pound, we're not talking about just prob…

Also, wont it theoretically speed up and decrease international shipping + travel. We should be able to go from the US to Japan in an hour or two in the future.

Maybe.

The fundamental physics involved in suborbital flights mean that you are likely experiencing sustained acceleration of 3+ Gs minimum. That is a lot, something near the max g force of a roller coaster but lasting for minutes. Combine that with the launch/landing zones needing to be many miles from anything, and it isn't really ready for primetime. Just for reference 1.3 Gs is the max sustained load you will feel in a regular airliner, very rarely 1.5 Gs for terrain avoidance.

For cargo, maybe medical stuff like moving organ donations around, but largely I can't imagine a ton of use cases where getting something to an antipode in 3 or 4 hours is that much more valuable than getting it there in 19 hours.

Then again, maybe I lack imagination.

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