zolotiyeruki

*Some* things inside a rocket engine are designed to handle high-heat stuff. And most of the hot stuff is on the inside. There's plenty of stuff outside the combustion chamber and bell that don't react too well to super high temperatures. Recall during some of the earlier SS hops, there were things catching fire under the skirt, from residual fuel burning after an engine shuts down, or turbulent airflow sucking burning stuff back up.

Can someone run through the math of this for me? That's a humongous difference in payload to orbit. I understand that disposable SS would not need heat shield tiles, fins of any sort, or fuel for deorbit and landing, plus fuel to get those things to orbit. Does all that add up to 100 tons worth of savings?

There's a joke that goes something like "at that kind of altitude, you wave at each air molecule as it passes by." The air is so thin that you need larger aerodynamic surfaces in order to maintain stability. At 50,000 feet, you have roughly 1/7 the air density you have at sea level. At 80,000 feet, you've got less than 1/20th as much air hitting your flying surfaces.

Reading through the Wikipedia article on it, yeah, it has a LOT of lifting surface, both horizontal and vertical.

The "shuttle" is usually supported by a separate rail, so that the screw sees no radial load, only axial.

I love the fact that Dragon has red and green navigation lights, just like an airplane.

As others have said, you don't need Starship as the re-entry vehicle for bulk materials. Could you launch Starship with a bunch of inflatable re-entry vehicles? I.e. a heatshield, parachutes, deorbit rocket motor, and inflatable enclosure to keep stuff from falling out? Stack 'em 100 deep in starship, and you can deorbit a whole lotta stuff for cheapish.

What I'm imagining is airflow running from tail-to-nose and trying to get under the scales.

I'd be concerned about "fish scale" tiles when SS does the backflip and final descent.

I think it's important to remember that the "$X hundreds per kg to orbit" is a bit misleading. It's an average cost. The first 1kg of cargo onboard a cargo dragon costs tens of millions of dollars. The last kg costs a few tens of dollars (for the extra fuel) at most.

Sorry, I'm behind on a bunch of stuff--life got crazy for a few days. I'll try to get to it tonight.

Two launch mounts (and sets of catching arms) makes me wonder about the idea of a SuperHeavyHeavy, with two side boosters and a core. I wouldn't want to be near such a beast during launch, that's for sure!

Even if SpaceX don't end up launching a given SH multiple times per day, there are *definitely* advantages to designing the whole system (SH + tower and everything with it) for rapid reuse. Lots of time (and therefore money) saved by not having to haul it back to shore, offload it, tip it over, transport it to the rocket factory, refurbish it, integrate it, truck it out to the launch pad, tip it up, etc. The new process, assuming it works, is "stick the booster back on the pad, stack SS on top, refuel, push the big red button." That certainly fits with the "best part is no part" ethos.

Cool! Let us know how it goes, and post the craft file if you can as well. You might also try using something like Precise Editor to vary the AoI of the wings--when I experimented with it, 3 or 4 degrees (and more wings) was more efficient than 5 degrees and fewer wings.

Thanks for the info on the tanks. Ok, having gone down a few of those rabbit holes about KSP's drag model, I unfortunately have to classify the nose-cones-in-a-fairing as an exploit. It is similar in a lot of ways to the "stick a shock cone on the back of the engine and offset it inward." At one point, out of curiosity, I actually ran the comparison with and without that rear nose cone, and found that it reduced drag by something like 30%.

The reason I ask is because it feels pretty exploity--in the real world, putting a nose cone inside a fairing won't affect your parasitic drag. What are the 0.625m LF tanks arranged around? It looks like you've got eight, radially attached, but I can't fit 8 around a 6.25m tank without overlapping, and if I attach them to a 1.25m core, there are gaps between them.

Do you have a reference for that? This is the first I've heard of that particular trick.

Why would you put the intake on the inside of the fairing? And what's the benefit of putting nose cones inside the fairing as well?

Hey @camacju would you mind posting the craft file for the airplane you took around 23 times? I'm trying to replicate it in stock KSP, and can't seem to match the arrangement.

What if, after landing on Mars, the now-empty tanks get reused as additional living/working space, a la a wet lab?

The idea is that there are (or may be) people who are unwilling to live in Texas as a result of the recent law that was passed, and so they will not pursue (or continue) employment with SpaceX in Texas. So SpaceX could be missing out on some talent.

If you're returning stuff from orbit, it seems like you could ferry up a reentry capsule (a refurbished cargo dragon, perhaps?), stuff your spools of fiber optics in that, and deorbit/recover it in the traditional manner.

Ah, interesting--I've never tried to fly a RAPIER at sea level that fast. You'll have to excuse my asking lots of questions--you've beaten the previous record by a substantial margin, so I want to make sure everything is kosher. For example, wings attached to parts inside a fairing, and sticking out of the fairing, *might* be an exploit. If having them attached internally but protruding through the fairing affects their performance, that's an exploit. The rules don't say anything against ablator being consumed, and the heatshield stays attached, so that's ok. No, deploying a fairing (i.e. shedding it) is not allowed--all the parts need to stay attached throughout. Out of curiosity, what did you have in mind?

How did you get to over 1900m/s? RAPIERS flame out at 1753 or so.

Looking at the tiles on the aerocovers, it sure seems like SpaceX is having to do the same thing at STS did--while not every tile is unique, there sure are a lot of custom tile shapes over there!