I’m not sure I’d go that far–they’re pretty similar molecular weight, and a lot of equipment is perfectly happy with O2, N2, or air (or an equivalent pure mixture of O2/N2). Probably O2 has a few more factors to consider due to reactivity, so maybe the right stance is that testing the O2 systems helps to prove out the N2 system, which is not what they did.
Regardless, system design is about more than testing the individual components, so even if the O2 and N2 subsystems are similar, they still have to work together, and they definitely haven’t tested that in orbit. Which is fairly scary.
Just don’t miswire the concentration sensors or connect the plumbing together wrongly. As well as an 80% N2 / 20% O2 atmosphere works, an 80% O2 / 20% N2 might get a little too exciting.
Yeah, that’s what I was referring to. The reactivity of oxygen has enough other factors to consider that, for terrestrial applications, oxygen equipment is deliberately made with the “wrong” threading direction (lefty tighty), just to make sure that nobody accidentally uses equipment meant for other gases with oxygen.
If a system successfully tests out for oxygen, I’d have no problem using it with nitrogen. But not vice-versa.
For 2024, the rate could jump to 50, then rocket to 100 in 2025.
Damn. Vandenberg is SpaceX’s side hustle. If they’re planning on 100 launches from there in 2025, then it’s probably twice that many from Florida. And these are Falcon 9s. The article says that “Next year, SpaceX will re-evaluate and conduct analysis with an eye toward certifying the first-stage boosters for 25 to 30 flights, he said”.
What this tells me in relation to Starship is that it’s going to be a few years before it really ramps up in flight rate. Which isn’t a surprise–it’s a difficult system. But it wouldn’t shock me if it were 2027 or later before the mass-to-orbit exceeds F9.
They may well view Starship as being totally booked due to Artemis, since that will likely eat dozens of launches. And in the meantime, Falcon 9 will continue to be a workhorse. This graph will only look worse for the competition in the coming years:
Some of their competition is going to need an inset in an inset so as to show up.
Oh great. This means my Nextdoor account is about to have twice as many “Did anyone just hear a loud noise” posts. Currently it’s about 10 similar questions like that per launch. I think I may need to close my account there.
Nice clean test there. They were also trying to do a Booster 10 static fire today, but didn’t quite make it. They still managed some prop load/unload testing.
They also did some testing of the “Pez dispenser” door:
Cute. Will be neat to see the Starlinks shooting out of it. Probably not for a few more flights, though.
Nextdoor is pretty bad at the best of times. Maybe with a high enough flight rate, people will eventually get used to it.
Nextdoor in my experience is the most racist place online, although it’s done in code (though sometimes not). With a higher flight cadence, brown people from south of us will be the obvious cargo.
What am I to gather from that video? I see starship sitting on it’s ass and some cars driving past. What am I missing?
Edit: I was thinking how Starship + Booster look smaller than Saturn V for some reason. That stepped back design of the V really emphasizes the height. Starship being straight up/down you can’t get a grasp on the scale. So it looks the size of a Titan II rocket, another unstepped design and not that large.
Nextdoor is a cesspool, but I use it to sell or give away items locally as it doesn’t seem to invite as many scammers as Craigslist.
Somewhat on topic, I’m shocked given how many times SpaceX has launched from Vanderberg in the last couple years at how many people have no idea what the noise is. It’s like people near the airport being surprised by jet noise. Which now that I say that, of course that’s also a staple of Nextdoor.
I’m guessing there are split-second by split-second adjustments done to rocket nozzle orientations that would have required a 1970s computer roughly the size of Kansas.
(That is also very similar to the reason quad-copter drones weren’t around then.)
Starship would have been difficult. Particularly the engines. The F-1 engine was hard enough; without computers, it was close to a trial-and-error process to achieve combustion stability. They eventually started injecting small explosive charges in the combustion chamber to prove that they’d achieved stability.
The Raptor engine went through an incredible level of simulation, tracking something like 300 intermediate combustion products with their finite-element tools. SpaceX engineers talked about their simulations here, and that was just one of the early versions (using GPU clusters for the computation).
Is there a toned-down version that could have worked? Maybe. The Soviets obviously did excellent work with computers that were even more primitive than what the US had, and developed excellent staged-combustion engines. So if you’re willing to give up a little performance, maybe it could have been done.
As for the rocket itself–ascent and engine control should be relatively easy, but the landing seems like a stretch. They’re using pretty sophisticated control systems. On the other hand, they do have a lot of mass to work with. You could add a few tons of computers to the booster and not notice.
But even the control algorithms themselves didn’t exist then. So whether it’s possible depends on what you’re willing to allow sending back in time.
As for the Falcon 9–the rocket itself is pretty straightforward, and something similar could have been built decades earlier. The engines use a cycle that the Soviets had advanced past in the 60s. The airframe uses an aluminum-lithium alloy with friction stir welding–a little advanced past what they had then, but they probably could have come close.
But here, there’s less mass available for a giant computer, and again the software and algorithms pose a problem. I vaguely wonder if a human could be trained to land one with sufficient training (piloted remotely, of course).
Jessica Jensen of SpaceX says that hardware for Starship flight three will be ready in January, and that the company expects to receive an FAA license in February.
Will that happen? But previous estimates were fairly accurate at this relative point in time. And this seems like a more straightforward and predictable situation than IFT-2 (no surprise environmental reviews, etc.). I’m looking forward to hearing about the failures in ITF-2 and what changes were made to ameliorate them.
Could be they’re waiting until we get closer for an infodump. That kind of thing always generates press. You want to get people excited before the next launch, but not too long before.
But previous estimates were fairly accurate at this relative point in time. And this seems like a more straightforward and predictable situation than IFT-2 (no surprise environmental reviews, etc.). I’m looking forward to hearing about the failures in ITF-2 and what changes were made to ameliorate them.