488 private links
thinkreal Ars Praetorian
22y
573
I’m still boggled by the contrast of approaches to engineering. How long have the Orion team been wringing hands over heat shield tiles after some anomalous but not disastrous effects? SpaceX - “let’s rip off a couple thousand tiles and see how the steel holds up, next year we want to try some new hardware somewhere around there” //
AverageDutchGuy Ars Scholae Palatinae
5y
822
Super3DPC said:
3 things that surprise me on this flight:
- How routine it feels. I no longer hurry to catch the launch live. I wait until the whole thing is over and skip the video forward a few times. 6 launches this and it's almost boring already. I'm just too spoiled.
- After re-entry we can see parts of Starship stainless steel change color to have rainbow tint. Can those skin be reuse without changing them? Rainbow tint on stainless means excessive oxidation IIRC.
- I thought they'd use RCS to reorient Starship before engine relight. I mean the whole point of relight test is to make sure Starship can re-enter the atmosphere right? Can't do re-enter atmosphere without RCS reorienting Starship before re-entry burn right?
Rainbow discoloration on stainless just means a (thin) oxidation film has happened (and the color can be a nice indicator of what temperature was reached (for the dark purple to dark blue observed on the ship it would be between 450 to 600 degrees centigrade respectively, with bright blue being reached around 540) If it didn't deform I see no reason why it would have to be replaced, unless excessive tempering would occur in the likely cold-rolled skin material and ultimate strength was impacted.
Edit to add: heat range given is accurate for AISI304, since Starship uses (iirc) AISI 301 it might be slightly off. Source: https://bssa.org.uk/bssa_articles/heat-tint-temper-colours-on-stainless-steel-surface-heated-in-air/. //
Endymio Smack-Fu Master, in training
2m
53
jeremyp66 said:
Reusable spacecraft have been done before.
None anywhere near this size and scale.
jeremyp66 said:
for perspective, the sixth launch of Saturn V put two men on the Moon.
At a cost of several percent of the nation's total GDP: roughly $290 billion in 2024 dollars. Musk is doing it for a little over 1% of this.
jeremyp66 said:
OK so let's stop pretending that SpaceX is doing this "privately". Starship is substantially funded by the US tax payers. Starship is part of Artemis.
No, more precisely, the preexisting Starship concept is being used in Artemis, among many other things. That's how Musk was able to underbid the competition. His original Artemis bid was ~$2.8B: competitors ranged from $4B to $10B, for proposals which were less competent and flexible as well. All the Artemis funds are only about a third of Starship's R&D costs alone, not even counting the operational costs of the moon mission itself. //
Endymio Smack-Fu Master, in training
2m
53
MagicDot said:
Another very small step forward, almost matching the achievements of 1962.
Saturn V put 2 men on the moon -- by throwing away the vast majority of the hardware used to get there. Starship will place 100 on the moon, plus cargo, at a cost of ~1% of Saturn V ... and keep all that pricey hardware to boot.
MagicDot said:
That definitely is an acid test...and Elon is clearly on acid to think he's pulling that off in his lifetime.
Interesting. I recall the exact thing said about Tesla's ability to compete against entrenched automakers, or their ability to manufacture their own batteries at scale, or SpaceX's ability to manufacture reusable rockets or launch a 6000+ satellite constellation.
