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Friday Fun Thread for June 7, 2024

Be advised: this thread is not for serious in-depth discussion of weighty topics (we have a link for that), this thread is not for anything Culture War related. This thread is for Fun. You got jokes? Share 'em. You got silly questions? Ask 'em.

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I really enjoyed the latest Starship test flight.

https://youtube.com/watch?v=lFkqZF-Ss7o&t=6250s

It stood out from the first launch (IFT-1) because that was nearly a total disaster: 3 (out of 33) booster engines failed immediately (then 2 more on the way up), and it practically crawled off the pad, which also failed and flung giant chunks of concrete far enough to hit ocean. If a few more engines had failed sooner we might have seen one of the biggest non-nuclear explosions in history. 4 minutes later (at only 29km up and 2100m/s) we did see a pretty big explosion, when they lost control before stage separation and had to terminate the whole flight, and even the termination didn't work properly, with the termination explosive damage taking half a minute to finish off a vehicle it should have wrecked in seconds.

It stood out from the second launch because it actually got the upper stage and booster into their planned trajectories after separation. In IFT-2, right after separation the booster was supposed to boost back towards a site closer offshore (for a controlled splashdown, practice for future returns to launch site), but LOX filters had some kind of blockage, 6 (out of 11) of the restarted booster engines started rapidly failing, and they had to blow it up instead. The upper stage made it almost to their target trajectory, started dumping excess LOX as planned ... and that interacted with a leak, started an engine bay fire, shut down the engines, and triggered another termination. At least all the explosives worked properly that time.

It stood out from the third launch because it actually brought both stages back to splashdown. In IFT-3 the boostback worked, but then the booster was having trouble with control during the descent and then with propellant for the landing burn, so instead of a controlled "landing" on the ocean they got an explosion half a kilometer up. Then, the "orbital" (actually very slightly suborbital, specifically as a fallback for what happened next) insertion worked ... except that their attitude control thrusters froze up. So they got to do their free fall experiments in space, but when it came time to reenter they were slowly spinning, and entered sideways instead of heat-shield-first.

I'm a die-hard SpaceX fan (for reasons discussed here), so take my opinion with a grain of salt too, but I'm excited about an excellent splashdown this time with the booster, and more importantly IMHO they just passed the hardest test in the whole program: getting the largest reentry vehicle in human history to decelerate from orbital velocity while still intact and (albeit barely, this time!) fully operable.

Hell, in honor of the Starship 29 Flap, let's push that "passed the test" metaphor to work far past the point it should have been expected to give up: SpaceX only passed their Advanced Launch Vehicles test with a low D-minus this time, and also the exam paper is kinda charred from where it accidentally caught fire right as they were finishing it, but that D-minus beats their 40% last time, 20% the time before that, and 5% the time before that, and whereas such failure would make other advanced students drop out, SpaceX seems determined to just keep retaking the damn test until they've got the same "A++ and extra credit and they corrected one of the professor's mistakes" they eventually reached on the Intermediate Launch Vehicles test with Falcon 9. And that's a big deal, because so far they're the only ones yet to even pass the Intermediate Launch Vehicles test. Space Shuttle got a low pass from the Teaching Assistant (NASA) but failed when the professor (physics) checked their work more carefully. Almost everybody else elected to only take Basic Launch Vehicles, on the theory that that was all you needed to earn a living, which was true once but is becoming more obsolete each year. The exceptions were a few poor students long ago who failed to scrape up the tuition, one rich student who is having to repeatedly audit the class until they find enough time to get ready for the preliminary exams, and a couple young students who seem pretty smart but either aren't ready to test quite yet or are still mastering the Basic test.