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Starship Flight 7

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Re: Starship Flight 7

#641

Post by drillsteps5 »

schiffern wrote: post #635
drillsteps5 wrote: post #613

Earlier quoted context omitted.

The problem is with the "hours" part. Which, not accidentally, is not even part of the SI.

In the official BIPM brochure, hours are technically classified as "Non-SI units accepted for use with SI." This puts them in the same category as liters, hectares, tonnes, decibels, etc. https://en.wikipedia.org/wiki/Non-SI_units_mentioned_in_the_...

I can read Wikipedia too. All the calculations are done in m, s, g, etc. if you want to dumb it down to the public you might as well go in miles per hour, leagues per day, etc., spaceflight is not the place where it is appropriate.

Re: Starship Flight 7

#642

Post by schiffern »

hooli_gan wrote: post #619
GiorgioG wrote: post #529

Earlier quoted context omitted.

I’m not a big fan of Elon Musk, but this is just the typical executive talking up their product and to some extent being overly optimistic about timelines. You’d think with the quantity of software engineers in HN this would be obvious, but the (rightful IMO) disdain for Elon Musk is resetting people’s brains.

The taxpayer is paying for these lies

If you think delays in aerospace constitute "lies," you're not going to have a good time following any aerospace company. Unexpected delays are par for the course.

Re: Starship Flight 7

#643

Post by m4rtink »

Alive-in-2025 wrote: post #632
m4rtink wrote: post #422

Earlier quoted context omitted.

Actually the Super Heavy (first stage) already uses heavy CO2 based fire suppression. Hopefully not that necessary in the long term, but should make it possible to get on with the testing in the short term.

What is a long term solution for this? Is there something more than "build tanks that don't leak"? I'm sure spaceX has top design and materials experts, now what ;-).

I think its likely not the tanks but rather the plumbing to engines and the engines themselves leaking (sense lines, etc).

Next engine revision (Raptor 3) should help, as it is much simplified and quite less likely to leak or get damaged during flight.

Re: Starship Flight 7

#644

Post by hooli_gan »

schiffern wrote: post #642
hooli_gan wrote: post #619

Earlier quoted context omitted.

The taxpayer is paying for these lies

If you think delays in aerospace constitute "lies," you're not going to have a good time following any aerospace company. Unexpected delays are par for the course.

If you think these are mere delays, then I have a bridge to sell to you

Re: Starship Flight 7

#645

Post by m4rtink »

varjag wrote: post #626
littlestymaar wrote: post #547

Earlier quoted context omitted.

If you cooled the mixture at low enough temperature, you'd stop it from burning (like when you pour water on top of a camp fire), but it's not clear how you're supposed to do that in a spaceship where you can't carry a few tons of water for your sprinklers.

There are other methods too, e.g. fire inhibitors (like Halon or whatever is allowed now) or shockwave to disrupt fire boundary. But I doubt they are very practical on a spaceship.

First stage (Super Heavy) is flushing the engine bay with massive ammounts of CO2.

Re: Starship Flight 7

#646

Post by mavhc »

Alive-in-2025 wrote: post #629
dpifke wrote: post #280

Earlier quoted context omitted.

Preliminary indication is that we had an oxygen/fuel leak in the cavity above the ship engine firewall that was large enough to build pressure in excess of the vent capacity. Apart from obviously double-checking for leaks, we will add fire suppression to that volume and probably increase vent area. Nothing so far suggests pushing next launch past next month. https://x.com/elonmusk/status/1880060983734858130

This sounds like one of those "and also" things. I'd say you add fire suppression AND ALSO try more to reduce leaks. It's got to be really difficult to build huge massive tanks that hold oxygen and other gases under pressure (liquid methane too will have some vapor of course). Are leaks inherently going to happen? This is meant to be a human rated ship of course, how will you reduce this danger? I know this stuff is…

Given that a) most human rated rockets have had 0 flights before use, and b) I'd expect each starship to have at least 10 flights, and at least 100 in total without mishap before launching, the statistics should be good

Re: Starship Flight 7

#647

Post by ceejayoz »

pclmulqdq wrote: post #639
ceejayoz wrote: post #589

Earlier quoted context omitted.

This is a very partial telling of the current situation. Orion is delayed due to a heat shield issue: https://www.nasa.gov/missions/artemis/nasa-identifies-cause-... The first SLS launch was six years behind and massively over budget. Lunar Gateway is almost certainly getting delayed. None of these programs rely on SpaceX in any way thus far.

There was no heat shield issue, it was investigated and the resolved: https://www.space.com/space-exploration/artemis/nasa-delays-... There is an issue with another dependency for Artemis 2 and 3, though - Starship is nowhere near where it needs to be.

"There was no heat shield issue" and "it was investigated and resolved" cannot both be true. There was a heat shield issue; they investigated for two years, and it has caused a delay.

Artemis II has no Starship dependency. It's entirely SLS/Orion.

Your own article agrees with me:

> Artemis 2 likely would've been delayed by a year or so, to late 2026, had a heat-shield replacement been required, NASA officials said today. But the mission team still needs more time than originally envisioned to get Orion up to crew-carrying speed, explaining the roughly six-month push.

> "The heat shield was installed in June 2023, and the root cause investigation took place in parallel to other assembly and testing activities to preserve as much schedule as possible."

Re: Starship Flight 7

#648

Post by fooker »

londons_explore wrote: post #573
pixl97 wrote: post #135

Earlier quoted context omitted.

I mean blowing liquid oxygen on something with a hot heat source beside it typically turns things to fuel you wouldn't expect. Like metal.

At atmospheric pressure, yes. But up at 140km altitude, the pressure is so low that I don't think even pure oxygen would lead to combustion.

There are two huge tanks providing the pressure here.

Re: Starship Flight 7

#650

Post by spandrew »

raverbashing wrote: post #370
dpifke wrote: post #280

Earlier quoted context omitted.

Preliminary indication is that we had an oxygen/fuel leak in the cavity above the ship engine firewall that was large enough to build pressure in excess of the vent capacity. Apart from obviously double-checking for leaks, we will add fire suppression to that volume and probably increase vent area. Nothing so far suggests pushing next launch past next month. https://x.com/elonmusk/status/1880060983734858130

I'm not sure there's fire suppression effective enough for this type of leak (especially given rocket constraints)

It might not even be about fire suppression. Oxygen and different gases can pool oddly in different types of gravity. If oxygen was leaking, it may be as simple as making sure a vacuum de-gases a chamber before going full throttle.

We know nothing, but the test having good data on what went wrong is a great starting point.

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