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SpaceX launches Starship v3 rocket

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Re: SpaceX launches Starship v3 rocket

#301

Post by stefan_lec »

generuso wrote: post #11

The views from Ship's engine bay looked rather ominous -- with the red glow visible in multiple places, and something venting furiously from the broken engine. It was a pleasant surprise that the ship did not explode and not only that, but it even landed exactly on target. Guidance system software engineers have done a very good job! The booster not completing the return part of the flight was disappointing. They had…

Yeah, the new raptors and engine bay redesign for version 3 of ship seem a lot more robust than version 2, very impressed that the ship finished its mission so well.

Scott Manley goes into quite a bit of detail on analyzing superheavy’s failed boostback, it’s a good watch:

https://youtu.be/2kxanBYTAaY

TL;DR - seems like the hot staging kicked the booster out in the wrong direction, and the ship’s plume impacted one of the grid fins, which would’ve given it quite a big kick. The sloshing just from that could easily have caused the observed issues.

Re: SpaceX launches Starship v3 rocket

#302

Post by stefan_lec »

MBCook wrote: post #24

I don’t keep up with them. What’s different compared to v2?

Biggest things changed are the plumbing inside the booster (much beefier, now supports starting all engines at once), and a new version of the engines, raptor v3 (more robust, and saves about 1 ton of mass per engine).

Cool image comparing the three versions of the engine. In addition to making the engine itself a bit lighter, moving all that stuff to the inside of the engine let them eliminate a whole bunch of heavy shielding in the engine bay.

https://ibb.co/pr0gx688

Re: SpaceX launches Starship v3 rocket

#303

Post by amluto »

le-mark wrote: post #240
amluto wrote: post #171

Earlier quoted context omitted.

I don’t think plutonium is the right comparison. Plutonium is expensive, and nuclear bombs are neither cheap nor particularly useful for doing things like attacking 10k different targets in some foreign country. I’m imagining a launcher in a spacecraft that kicks out a bunch of payloads, one at a time, out the back, into orbits with perigee on or before the ground. (An LLM calculates the needed delta-V at under 200m/…

Near real time fpv drones anywhere on the planet, free of jamming due to starlink is the real game changing capability. What would any military pay for that? Plenty I wager.

Wait a moment. How exactly is Starship supposed to usefully deliver a pile of FPV drones to a hostile area?

Starship itself is highly engineered to survive reentry and can even land anywhere that an appropriately flat surface is available. It will conveniently toast anything hanging out on the landing zone. But it is extremely far from stealthy, it seems likely to be extremely vulnerable both before and after landing (a hole in a cryogenic fuel tank = big boom), and I don’t think any of the design mission profiles involve Starship’s second stage, minus most of its fuel and minus the first stage, taking off again from Earth. And the value proposition isn’t there if you don’t get to reuse it.

A common cheap FPV drone dropped from orbit or from a suborbital ballistic trajectory is a small meteor, not a weapon.

ISTM it would be a better bet to equip an F-35 or a larger UAV to drop a pile of small drones.

Re: SpaceX launches Starship v3 rocket

#304

Post by throwaway85825 »

XorNot wrote: post #264
throwaway85825 wrote: post #250

Earlier quoted context omitted.

The shahed/geran is just a low cost cruise missile. The f35 comparable is a loyal wingman that does manned/unmanned teaming and carries A/A and A/G.

Loyal wingman aircraft would have to be stealthy though to do it. The whole point of the F-35 is that it is a stealthy platform with a very advanced set of targeting and weapons capabilities: but the issue is a similar capability drone would basically have a similar price tag since the expense of the pilot is minor in that case. Like plausibly the best autonomous F-35 platform would just be an F-35.

There are at least a dozen stealth loyal wingman programs/prototypes.

Re: SpaceX launches Starship v3 rocket

#305

Post by throwaway85825 »

fragmede wrote: post #266
XorNot wrote: post #264

Earlier quoted context omitted.

Loyal wingman aircraft would have to be stealthy though to do it. The whole point of the F-35 is that it is a stealthy platform with a very advanced set of targeting and weapons capabilities: but the issue is a similar capability drone would basically have a similar price tag since the expense of the pilot is minor in that case. Like plausibly the best autonomous F-35 platform would just be an F-35.

It's not the expense of the pilot but the fact that the human pilot is subject to human biological constraints. Ie they black out after 9 Gs or so. An autonomous platform you'd want to design to be able to routinely do outside that envelope in a way that a platform designed for a human occupant is not.

The US lost several aircraft rescuing the downed pilot in Iran. Not necessary with drones.

Re: SpaceX launches Starship v3 rocket

#306

Post by cwillu »

ajross wrote: post #31
bbatha wrote: post #17

Earlier quoted context omitted.

Moreover the two lost shuttles included human lives. Better to blow stuff up with demo payloads now before sending up large contracted payloads or worse human beings!

> Better to [...] That's undeniably true. Nonetheless "Better than the shuttle, which sucked" isn't the design goal. The question is not even just "is it better to blow up 12 Starships?", which would probably still be true. It's " Why isn't Starship working yet? " and the implied " Maybe Starship sucks too?! ".

They failed far more than 12 landings before they started reliably landing boosters, and people made the same “maybe this is a dumb idea” comments back then too.

Re: SpaceX launches Starship v3 rocket

#307

Post by Rp8yXmdmr »

makemoney-2003 wrote: post #230

many would think it was a failure lauch before going public

I am not sure results of single test launch matter much. The issues with SpaceX IPO aren't even related to rockets: it is the very low float, Musk making himself irremovable from CEO seat, and buying xAI at inflated valuation. If people are willing to buy such stock, even V3 blowing up at launch pad won't stop them.

Re: SpaceX launches Starship v3 rocket

#308

Post by cma »

dnautics wrote: post #82
jordanb wrote: post #76

Earlier quoted context omitted.

Shuttle's tiles not being durable as hoped is what killed it's turnaround time. The problem was never solved and turned what was supposed to be a few days into weeks or months. Every mission the shuttle had to go back into the assembly building and have all tiles inspected and potentially replaced.

Shuttle tiles were also unique per position and starship tiles have a few base forms that are interchangeable

I thought Starship has many unique tiles, they ended up needing to vary thickness to match heat patterns to save weight and have some complicated geometry near the fins.

Shuttle had more unique perimeter shapes, but starship still has a lot of variation due to tickness. I don't know if that is easier to vary in production or still needs custom molds for the variation.

Re: SpaceX launches Starship v3 rocket

#309

Post by TheOtherHobbes »

XorNot wrote: post #264
throwaway85825 wrote: post #250

Earlier quoted context omitted.

The shahed/geran is just a low cost cruise missile. The f35 comparable is a loyal wingman that does manned/unmanned teaming and carries A/A and A/G.

Loyal wingman aircraft would have to be stealthy though to do it. The whole point of the F-35 is that it is a stealthy platform with a very advanced set of targeting and weapons capabilities: but the issue is a similar capability drone would basically have a similar price tag since the expense of the pilot is minor in that case. Like plausibly the best autonomous F-35 platform would just be an F-35.

Low-level drones are also stealthy. If they're not stealthy enough you can send them in bulk to overwhelm defences.

Ukraine's success with precision targeting of Russian assets would have been unthinkable with a fleet of F-35s and associated missiles because of the cost.

Cheap, smart, disposable drones are orders of magnitude cheaper and at least as effective for many mission profiles.

Re: SpaceX launches Starship v3 rocket

#310

Post by Gravityloss »

p_l wrote: post #172
throwaway85825 wrote: post #168

Earlier quoted context omitted.

The main reason the Mig29s have a reputation for easy maintenance is because they don't replace parts, they just throw away the whole airframe. The structural and engine service life is like 1/10th that of western fighters.

Not really. This "reputation" is based on misunderstanding of differences in doctrine. The engines did have lower overall hours, yes, but the suggestion they need whole overhaul after very few hours is because it looks so when looking at it from USAF doctrine where "removing engine and sending it to special facility" is only for rare complete overhauls, and local mechanics are supposed to do regular minor work all th…

Me-109 was similar
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