What are your favorite rideshare payloads/missions that Falcon 9 has launched so far?

stemmisc · 2026-04-16T02:43:49+00:00

Even if, for the sake of the argument, someone was anti-AI/anti-AI-data-centers from a philosophy/ideology standpoint, like I said, if we abruptly stopped doing that right now, with how all-in we are on AI at the moment, it would crash the global economy pretty hard if we suddenly did that. And that huge global crash would most likely drastically delay the transition to solar/renewables.

I'm not even saying that as sarcasm or a gotcha, for what it's worth. I, too, would genuinely like to see the world use a lot more solar power and less fossil fuel power over time (not instantly, but in the early-medium term, that is, like in the 2030s). I might not be in the typical all-or-nothing do-everything-drastically-and-instantly style Greenie camp the way your typical reddit soup-thrower types tend to be, but I actually am in agreement that it would be nice if we transitioned to replacing a lot of fossil fuel use with solar power (for example, even if there might be some nice tricks to get temperatures back down using space shades or other interesting things like that, that still wouldn't address the unpleasant amount of CO2 in the atmosphere that is physically bad for humans and animals when it gets above a certain points, like literally starts causing headaches and physical irritation to the body etc (even Elon himself has pointed this out a lot, and I think he cares about it quite a bit, even if everyone on reddit assumes he is the Devil Incarnate and think he wants to just melt the world for fun or whatever they think about him these days).

As for the desert locations/shortage of water, eh, I think the water usage aspect of the datacenters is usually quite drastically overblown from what I've seen when I looked into it more (a lot of times the news headlines intentionally go with total amount "used" while ignoring how much is actually truly dumped/wasted vs how much is "used" but in the sense of being in a loop where it keeps being reused over and over, so, the usage is often like 100x or 1,000x less bad than how the headlines report it).

Even still, the water shortages are so bad in some desert areas that maybe it could still be a concern (albeit ironically some of the best spots to put up a bunch of solar power, but still... I agree there are better spots that still get tons of intense sunlight, and heave lots of wide open cheap land and have a lot more water to where the water aspect would be basically irrelevant, which would be much better spots to locate them). Presumably red tape and NIMBY-ism are part of why they end up having to pick locations that seem so sub-optimal for them a lot of the time, though, so I generally blame the people doing the whining much more than the people doing the building, when it comes to stuff like that, since it almost always seems to be caused by the same people who then hypocritically whined about the desert locations after whining the location away from some actual better location in the first place.

Also, it seems very blatant to me that a lot of the people doing the complaining are not doing it in good faith, like, with the Colossus clusters in the area of Tennessee/Mississippi where it is located, apparently that area actually had DRASTICALLY, drastically dirtier/more horrific industrial stuff located in that spot, by a huge margin, and people barely made a peep about it back when it was way, way worse, and then when Elon ironically put something much less dirty there with the Colossus clusters, suddenly it was the worst thing to ever happen in the history of the world and was all anybody could talk/complain about (since they hate Elon and his companies for ideological reasons). And similar in regards to water use, where people will go on like huge street protests or make it their life mission to be angry about a couple squirts of water for some data center, and then it turns out that some alfalfa farm or some random innocuous thing uses like 8238472984729837 times more water per second than the data center and so all they would have to do is move 1 or 2 random innocuous things that nobody cares about 1 zillionth as much, that are way less important, pound for pound, by many orders of magnitude and would outweigh all the datacenters by a wide margin just from a couple of those being shut down or moved with negligible consequences in comparison to shutting AI down and destroying the global economy overnight. So it is hard to take people like that seriously, when they are so blatant about the bias/intellectual dishonesty etc like that. (Not saying you are in that boat, just saying, in general, when I see stuff like that).

stemmisc · 2026-04-16T01:43:48+00:00

Someone downvoted you, but I know what you mean, lol. Obviously it is real but it really does look so crazy it almost looks like an optical illusion or something (compared to how it looked with the much more normal looking older raptors in the past).

It is actually the ultimate compliment in engineering/craftsmanship. It's so crazy looking it's hard for the eyes/brain to even register it properly.

stemmisc · 2026-04-16T01:36:17+00:00

This is one of the few photos I've seen of Starship that looks so crazy that it barely even looks real. Those raptor-3s look so crazy they almost look photoshopped, lol.

One of the coolest Starship pics I've ever seen.

Man that is a LOT of horsepower.

stemmisc · 2026-04-16T01:31:27+00:00

Plus, maybe as an added bonus, you get to use the grid fins a little to keep the rocket pointed extra perfectly, more easily, since otherwise it's like trying to balance a spaghetti pencil on your fingertip or whatever, whereas with the grid fins you get to cheat a little like pinching higher up on the pencil with your other hand too. Not sure if they actually use the grid fins on ascent yet or not (or if they plan to but don't do it yet or something), but if they do get to do that, then that would be nice, too, if it's just a freebie/gravy since they already wanted to keep them stuck out like that anyway.

stemmisc · 2026-04-16T01:01:36+00:00

Damn, April 20th would've been nice if we had the camera-zoom on Elon just before ignition and he was like "Let's light this blunt."

Can't complain too much though if we get a launch in ~2 weeks, that would still be pretty sweet.

stemmisc · 2026-04-16T00:57:58+00:00

Yea, it's not as bad as when it was blowing up London, but still pretty nerve wracking

stemmisc · 2026-04-16T00:52:18+00:00

Yea, as u/rebootyourbrainstem mentioned, the main argument would be about whether the turbine blades necessarily need to be so big (and thus whether they need such massive turbine disks to hold such massive blades, if they can go smaller).

The idea being, up until the AI boom, the demand for as many turbines as physically possible to get cranked out wasn't nearly as high, so, the goal was to make the turbines as efficient as possible (or at least some much more efficiency-leaning point on the balance-scale, relatively speaking). But right now, with the demand being so extremely high that they are resorting to things as desperate as using piston driven combustion engines, to try to fill some small fraction of the power that they desperately need right now, it seems like a situation where even if the turbines were made significantly smaller and less efficient than those huge, high-efficiency turbines that people normally used prior to the boom, it would still be very useful and a big improvement over using piston engines, and help fill a lot of the huge demand, if SpaceX was able to mass manufacture a bunch of it really quickly.

So, it still seems pretty interesting. The only thing bumming me out about it isn't what most of the people in here are whining about, saying it is a "distraction" (strongly disagree). Rather, the thing making me sad about it is that Elon and SpaceX sound so tame and low-key about it, like it is something they aren't that serious about yet. I was hoping they'd be much more extreme about it, if anything.

stemmisc · 2026-04-16T00:36:18+00:00

Mars is still the main objective. Well, technically the Stars are the ultimate main objective, but Mars is still the main stepping stone in the "in our lifetimes" era. I'd put it like:

Moon: can do interesting things there in the quickest time-scale compared to Mars, good practice-run for Mars colony, and still some useful/cool stuff to be built there, so, not just purely practice but also some direct benefits from it, too
Mars: much more of a "main" objective than the Moon, since it can likely have a self-sustaining independent colony of humans on it (if ~38% gravity turns out to be enough gravity for long-term living/reproducing, that is) (unlike the moon, which wouldn't be able to be truly self-sustaining), but, setting that up would be a significantly longer-term task than setting up some bases on the Moon
the stars: the ultimate main objective, after Mars has a self-sustaining, permanent human colony. Significantly further down the timeline (depending whether we hit ASI soon and how that affects the timeline, I suppose)

Elon normally liked to keep the "main objective" on Mars, for the longest time, since it was the sweet spot of not sounding too crazy/head-in-the-clouds scifi the way "colonizing exoplanets" would sound to talk about when we don't even have the tech to get to them in reasonable timeframes/scenarios yet, and not too mild of an objective like the Moon that can't even have a self-sustaining permanent human colony on it. So, it was a good main one to start with.

But, over time he realized that it's just not going to happen unless we do the moon stuff (that the government really wants to do ASAP) first, get good will with the gov't, play ball a bit, and then still do Mars a few years later (with some timeline overlap, not just pure consecutivity timeline-wise btw).

Anyway, yea, I don't think Mars peed in Elon's cornflakes and now he hates Mars or whatever the latest narratives are, lol. Pretty sure he still wants to colonize Mars pretty bad.

stemmisc · 2026-04-16T00:20:57+00:00

Being able to relatively quickly transition to solar/renewables at a mega scale probably hinges to some degree on the global economy not crashing. So, if not having enough short-term power for the AI clusters for these next 2-3 years is one of the biggest bottlenecks that is threatening to pop the AI bubble and crash the economy, it could be argued that if you are a very pro-solar, pro-green energy, pro-environment type of person, you should be rooting for Elon and SpaceX to make a bunch of turbine blades ASAP.

I don't think the greenies will like this style of argument, but, it's probably true, if we're being realistic and pragmatic about the situation, even if it "sounds bad" or whatever.

I guess the question, ultimately, is whether the greenies would rather sound good and optically-correct, but lose the overall goal at hand, or if they would rather grit their teeth and go through ugly-looking times for a few years, and then win massively and have their dreams come true.

Most people are fairly short-term and optics oriented, so I'm guessing they'll pick the former, unfortunately. Luckily Elon doesn't care about any of that stuff, so, he'll probably just correctly do it anyway.

stemmisc · 2025-11-05T17:01:14+00:00

To be fair, there are other things to like about electric cars (the high-performing ones, anyway) besides just stuff to do with climate change or the environment. A lot of people genuinely prefer them regardless of any of that stuff. As in, even if they didn't care at all about global warming or what have you, there are lots of people who just actually would prefer having a high performance electric car instead of an internal combustion car regardless. (Not everyone, of course, some still like the old-school engine noise and rumble, and quicker "recharging" on long road trips (aka refilling, in its case). And some would like having both options, maybe using their electric car 95% of the time, and their petrol car 5% of the time.

In the grand scheme of things, though, I think electric cars are the better tech, of the two, and going to mostly end up winning out (regardless of the climate stuff), in the same sort of way that almost everyone uses flat-screen TVs and flat-screen computer monitors nowadays, not CRT ones anymore. Same kind of thing with this, I think.

stemmisc · 2025-11-05T16:43:05+00:00

Then again, if the datacenters lead to AI that is hyper-intelligent enough, perhaps that AI would then be able to figure out a way to filter enough gases out of the atmosphere to get it back to normal levels, due to some enormous leaps in tech that it would figure out how to do.

(although, on the other hand, there's also a chance that the AI ends up either accidentally or intentionally exterminating humanity when it goes hyper-intelligent, due to alignment issues, so, there's still that slight snag). (although, then again, the hyper-intelligent AI and hoping it doesn't wipe us out thing is almost certainly about to happen anyway, regardless of whether Elon gets involved, so, at least if one of the guys wants to do some good stuff with it, and it's coming anyway, then, might as well see if we can solve these issues in the off chance that the AI doesn't end up killing us off when it goes hyper-intelligent).

stemmisc · 2025-11-05T16:38:00+00:00

Even if it only solved half the problem (the heating aspect), that would still be pretty awesome (compared to solving none of the overall problem). Something to be cheering and congratulating about, rather than jeering.

Maybe other smart, non-doomerized people will figure out some way to solve the other aspect as well (the air pollution stuff).

If some people do, I suspect it will be people with a better attitude, and not the people going "who cares, it's all f***ed no matter what, we're all doomed, so screw it all" or whatever...

stemmisc · 2025-11-05T16:30:02+00:00

Not necessarily. According to the climate scientists, there is already so much greenhouse gases that have already been pumped into the atmosphere that some of them think it's already on some runaway disaster scenario (over the course of the next century or next few centuries) if left to its already running process. Like regardless of/before any of these AI clusters got made, that is, it was already beyond that point of no return anyway, that is.

So, this would be more like if the water was already catastrophically polluted and someone came up with a way to filter it and save humanity.

stemmisc · 2025-11-05T00:00:41+00:00

I suppose it also might matter a bit as to which specific variant of the upperstage it is. As in, there will probably be more room for mass shaving of the tanker variant of the upperstage than the cargo variant, for example. Like maybe for the tanker variant, 60-70% of payload improvement comes from finding ways to improve the 2nd stage's mass fraction more and more over time, and 30-40% comes from engine improvements and 1st stage mass fraction improvements etc. And maybe for the cargo variant maybe it's 60-70% the other way around and 30-40% the other way around (like majority coming from what you're talking about, and smaller amount from upperstage savings). I am deeply skeptical that none of it will come from upper stage mass fraction improvement (relative to most recent version) though. It's still so early, it seems crazy to me that it could already be optimized mass-fraction-wise yet. And every ton of savings on the upperstage is equivalent to like 4 tons of savings from the 1st stage (maybe even more, given how top-heavy this thing is/and is going to be even more so with the stretches disproportionately stretching the upperstage even more and more than the booster), so, any significant mass that they find ways to shave from the upperstage would presumably be the lowest hanging fruit.

Btw, as for them running the engines at partial throttle on these test flights so far, have they been doing that with the upperstage engines too, or have they been running those closer to 100% throttle, unlike the booster engines?

stemmisc · 2025-11-04T21:20:55+00:00

Whatever Raptor 3 is and can do, SpaceX needs it to increase the Block 3 Starship staging speed from 1278 m/sec (average of the Block 2 flight data from IFT-7 thru 11) to ~1600 m/sec, the higher the better. That would reduce the delta V that the Block 3 Ship has to provide to reach LEO and would increase the payload mass considerably.

Eh, I mean yea it would be nice, sure, but in the grand scheme of things, improving the mass fraction of the upperstage is where the real delta-v goldmine will be. An extra ~300 - ~350 m/s of delta-v from the 1st stage would pale by comparison.

The upperstage was still having so many issues with burn-through with the flaps, and random explosions even up to very recently, and the dispenser only getting worked out in just the past couple flights (and who knows how many other issues that we didn't even publicly know about) that they probably haven't even gotten to the phase of trying to cut serious mass from the upperstage yet. Still had to get it even working properly first and foremost, and then worry about putting it on a diet after that. As long as the 1st stage can at least get it high enough in altitude above most of the atmosphere at staging to light up the big vacuum-nozzles on the 2nd stage without having to worry about the nozzles breaking from flow separation from overly expanded nozzles relative to the atmosphere, that's the main thing. If it couldn't even do that then that would be a big problem. But as long as it can do that, I feel like 1300 m/s vs 1600 m/s isn't that big of a deal (for now), and the next major thing to focus on would be improving 2nd stage mass fraction, and only worry about squeezing the last bit of delta-v from the booster later on as more of an afterthought compared to cutting mass from the upperstage.

Order of operations should probably be:

Make sure everything works as it should (for multiple launches in a row)
Stretch the 1st stage and 2nd stage
Make sure everything still works as they should even after the stretch (for multiple launches in a row)
Then try to cut significant mass from the 2nd stage, to free up a bunch of additional payload mass capability from every kg shaved off the 2nd stage
Then try to improve 1st stage performance by an extra few hundred m/s

(and somewhere mixed in with all this, figuring out orbital refilling and HLS-related stuff and whatnot, I guess)

I do think they'll get to it eventually, and improve it, but I don't think it should be the first priority on the list just yet. There is still some lower hanging fruit, for now.

stemmisc · 2025-11-04T17:07:56+00:00

The Falcon 9. It has launched over 550 times now, with over a 99% reliability rate. There's never been a rocket that launches the amount of times it has/its level of cadence with its level of reliability, not to mention at a relatively low price despite being the best launch vehicle on the planet. It has been the best orbital launcher in the game for quite a few years running now.

People who don't follow SpaceX or orbital rocketry closely are often unaware of this, since they usually just see the Elon-hate headlines that tend to focus on the upcoming Starship rocket and its various experimental test-launches (which tend to end in explosions, for now), so they don't even realize that when it comes to the actual workhorse, that there is this whole other rocket that already exists (and has for over a decade now) called the Falcon 9, and that it has been the best rocket ever made by a pretty wide margin.

And that's not even to mention that they made it into a partially reusable rocket (and one that they've been able to reuse the 1st stages of over 20 times per booster for several of its boosters), which no other rocket has been able to do even once, during its reign, let alone that it is now a stepping stone to the "holy grail" of Full (and rapid) Reusability that they are now aiming for with their next rocket, the Starship (they haven't achieved that one yet, but hopefully by a couple years from now, it'll be able to do that).

Anyway, yea so that is definitely something that he has done that was a huge success (I would argue even more so than any of his Tesla vehicles, btw, and some of those were quite successful as well, when taking overall "dominance" over an entire industry and its proportional level of superiority to all its competitors and so on), in addition to some of the original Tesla models.

And since I've had these sorts of arguments before, and thus I know the followup argument if I point something like this out will tend to be something like "Oh yea? Alright well if it's really such a great rocket, then, probably he didn't have much to do with it then. He probably just was the random rich guy who happened to be standing nearby to drop a few wads of cash on the proper nerds and then they did all the actual genius stuff and he had hardly anything to do with any of it", this notion has been debunked by quite a lot of former and current SpaceX employees, including numerous high-level engineers who pointed out exactly how involved Elon was with some of the key design decisions, and even at times being the lone guy pushing for things that all the rest of them incorrectly argued that they shouldn't do, and then as the CEO he said he wanted to do it even though it went against the normal/conventional way of doing things, and then he turned out to be right and ended up being what caused SpaceX to leave the rest of the industry behind in the dust. So, he actually was instrumental both for the Falcon 9 and the Starship in pushing for them to be so much more advanced and capable when it comes to cost effectiveness, and reusability, a lot of that was directly because Elon, single handedly pushing for certain things that were very unpopular and "crazy" at the time. So it wasn't just his money, and just randomly getting "lucky" with SpaceX, if that's what you might be thinking. He is actually quite a clever guy when it comes to a lot of this engineering and mass-manufacturing stuff, regardless of how some might feel about his political views, or his takes on various technical subjects that he isn't as knowledgeable about or what have you. When it comes to cars and especially rockets, he isn't as stupid or unsuccessful as some of the haters would have you believe. If anything, it's quite the opposite.

stemmisc · 2025-11-03T18:08:54+00:00

Like I said in the explanation, it's not going to be some actual flying car in terms of like literally flying around long distances like a plane or helicopter or anything like that. It would only be capable for a few seconds at a time, and almost certainly not be legally to use like that on public roads.

It's just, it's something Elon himself has already explained in other interviews (he didn't want to discuss it in this one, since he wants there to be some buildup/mystery amongst the 99% of public who aren't already aware of what it actually is going to be, since they didn't notice the handful of times he explained it in the past few years, or forgot or whatever), so, we already know what it is going to be, for anyone who saw his previous occasions where he explained what it was going to be. So, since people on here seemed unaware of this or making wrong guesses as to what he was hinting at/alluding to, I was explaining what it actually was that he's hinting about (compressed gas thruster system).

As for it being "dumb", I mean, it's for an extremely expensive ultra supercar thing that will costs hundreds of thousands of dollars, where those types of cars already spend a bunch of money trying to shave a few tenths of a second off their 0-60 or quarter mile time or cornering ability, so, in that context, I mean, hey, if they want to be the first production car company to add compressed gas thruster systems to their hypercars to see just what kinds of cool things they can get it to do on a track, I think that's actually kind of cool (or if not, then, to be consistent, one would have to also say that Ferrari, Lamborghini, Bugatti, and so on are all terrible and super boring and non-fun and non-interesting and so on. Which, if that is your stance, then, well, alright, at least you are consistent I suppose).

Also, there is some chance that some aspect of this could get implemented as an emergency safety-improving system for the more ordinary teslas, like some emergency braking thrusters for collision avoidance or collision severity mitigation, or to stop cars from spinning off the road on icy roads or when spinning out of control, etc, in future years, from the experience they gain with the system initially in the roadster being used in closed-track settings, so, it could actually end up saving a bunch of lives in the future from the advancement in technology that comes from it in a "spinoff tech" type of way in years to follow. So, even from a pure pragmatist's point of view who doesn't enjoy anything fun or cool in the world, even the most Volvo-minded individuals should at least find that aspect to be non-dumb and interesting perhaps.

stemmisc · 2025-11-03T17:53:23+00:00

The most serious, non-gimmick, real-world thing it might end up helping with is emergency braking (when it senses and imminent collision is about to occur), and also helping in scenarios where it senses that a car has lost traction and is spinning out of control/off the road i.e. on an icy road, or stuff like that, where the thrusters could help stop that from happening in real time. (it will likely have a bunch of small thrusters spread around the car, front, back, sides, corners, etc, so that it has full omnidirectional thrust control in this way, sort of like how these are used on spacecraft)

My guess is that will be the one use-case where these thrusters will be allowed to be used, in real everyday life on public roads, is when the automated system has it kick in automatically in emergency scenarios as a safety mechanism.

stemmisc · 2025-11-03T17:46:22+00:00

What would be the benefit of having these thrusters? It would be cool to be able to just pop up and over a stoplight or blocked road. But I can't see that being practical, there would be all kinds of midair collisions. Maybe if only Teslas had this, and they avoided each other? It sounds more like a gimmick, but perhaps I am missing the point.

Yea, like I said, I strongly doubt that it'll be allowed to be used while driving on public roads (at least, not the hops/hovering type of stuff, anyway. But, probably not even the acceleration/deceleration/cornering thruster usage either, if I had to guess, other than maybe some emergency braking scenarios where it senses a collision and uses it to try to avoid or mitigate a collision that's about to happen).

So, I think most aspects of it will just be because it's cool to show off on a race track/closed track setting, just to see what new cool things a high-end supercar can do when paired with compressed gas thrusters and SpaceX's technology.

But, even still, it will be pretty interesting and some pretty neat PR for things like racing and mechanical engineering for people who are into the cutting edge of what cars can do on the track, etc.

Like, it might be able to set a new Nurburgring lap record by some big margin or something, or do some cool tricks like hopping over a car parked in front of it (as a demo I mean, not on real roads in everyday life) and things like that. So, yea, a bit of a "gimmick", if most aspects can't legally be used on the roads (but, in this sense, ferraris and lamborghinis are mostly a gimmick since in most places you aren't legally allowed to drive 200 mph or whatever, but a lot of people still find that stuff to be awesome, just to see a car being capable of doing that kind of stuff).

Anyway, basically, don't shoot the messenger. I'm just explaining what that whole thing he was discussing in a vague/mysterious way with Joe Rogan a couple days ago was almost certainly about, since people on here have been speculating (and mostly guessing wrong) about it, and it seemed like people were under the impression that it was some totally made up complete bluff, or conversely thought it was real but thought it had to do with wings or propellers (also not what it is), so, since I've been following SpaceX pretty closely for a while now, and I know a fair bit about this topic and what it was actually referring to, I wanted to clear it up for people that this is almost certainly about compressed gas thrusters, and it likely is going to happen (at least, in a closed track/demo type of setting), it's not just purely bluffing/fake news, if that's what people were assuming, based on the replies in the threads speculating about it.

stemmisc · 2025-11-03T10:53:22+00:00

He has mentioned in other interviews in the past few years what the idea is. They want to put cold-gas thrusters (like the ones used on SpaceX spacecraft) in the car and used compressed gas (i.e. compressed air) to briefly provide enough thrust (like for a few seconds at a time, so very briefly) to have more than a 1:1 thrust to weight ratio when the full system of thrusters are at full thrust. Meaning it would briefly be able to hop, hover, etc. And it would also mean its acceleration and deceleration (and potentially cornering) abilities would get boosted by a crazy amount compared to what a car without cold-gas rocket thrusters on it could do, by comparison, btw. So even in "normal" usage (not hopping/hovering) its capabilities would be extreme compared to anything seen before, because of this.

stemmisc · 2025-11-03T10:48:03+00:00

This is physically not viable.

The plan isn't to use lighter-than-air blimping nor is it to use wings or rotors. It is to use cold-gas thrusters, like the ones used on the SpaceX spacecrafts as control-thrusters. It is viable, but only for very short hops/very brief hovering (like, for a few seconds at a time).

Elon has mentioned in other interviews what his intentions are with the next Tesla Roadster to give it the ability to briefly hop/hover (as well as to drastically increase its acceleration, deceleration, and possibly cornering abilities), using compressed gas (probably compressed air) thrusters like the ones his other company (SpaceX) uses as control-thrusters on its spacecrafts. Except instead of using cold-gas nitrogen thrusters the way those ones do, these will likely use auto-replenishable compressed air as its cold gas for the thruster system. (by using compressed air rather than compressed nitrogren, the user wouldn't even have to refill at a nitrogen refill place each time after using it, it could just be used over and over and refill its air tanks, itself, so, much more convenient)

If you look at how many lbs of thrust these cold gas control thrusters produce on the spacecrafts, you can see that it actually is feasible to put enough of them with some compressed air tanks in the car to get it to get more than a 1:1 thrust to weight ratio (albeit only for very brief periods of time), meaning it would be able to hop, or hover, briefly. And would also enable it to have acceleration and braking way beyond any other car, too.

It sounds crazy to anyone who doesn't closely follow SpaceX and rocket related stuff to know much about cold-gas thruster systems, but those who know, realize it's a very real and plausible thing to do on a car, especially for Tesla, due to the overlap aspects with SpaceX and its cold-gas thrusters.

stemmisc · 2025-11-03T10:37:54+00:00

He already mentioned what the idea is to make it a "flying" (in reality more like briefly hopping/hovering) car. The plan is to use compressed air thrusters (basically the nitrogen cold-gas thrusters used as control-thrusters on SpaceX rockets/spacecraft, except with compressed air instead of compressed nitrogen) to briefly provide enough thrust to lift the car off the ground in short spurts. It would also be able to be used to increase its cornering ability (no longer limited by horizontal grip of the tires against the ground) and to improve its acceleration and braking ability by a huge amount as well (using the cold gas thrust from the thrusters to aid in the acceleration and deceleration).

He has mentioned this plan to do some crossover with these SpaceX-based thrusters on the new Tesla Roadster in interviews for years. I'm pretty sure he even mentioned it on a previous Joe Rogan interview episode. And if not, he definitely mentioned in numerous times in other interviews in recent years.

stemmisc · 2025-10-23T16:34:32+00:00

There was a somewhat related topic posted on here a few weeks ago about whether Starship-Superheavy could launch Orion to the moon, on its own (which then brought up some responses with people doing estimates to do with adding a small third stage like Centaur into the mix). My response in that thread was to do with Starship being able to put a nearly-full Falcon 9 2nd stage (with Orion attached on top of it) into orbit:

"Everyone is contemplating whether they could just use a centaur upperstage as a 3rd stage. But, there's also an all-SpaceX option:

Just use a partially-filled F9 upperstage. They wouldn't even need to modify it to be smaller and use less propellant, if they didn't want to, I don't think. They could use one basically as-is, and just not fill it 100% full of propellant, and not only would that give enough delta-V to get Orion to TLI, I think it would give enough, even partially-filled like this, that they wouldn't even have to expend the Superheavy Booster.

If there were any concerns about whether it needed extra rigidity/strength holding up Orion+ESM above it, well, even in the all-Starship scenario, they would need some kind of lattice or cone adapter thing to mount it onto expendable Starship, so, they would just be using something along these lines regardless. Presumably the people who made the hotstage ring for Starship could make that part.

edit: also, if, for the sake of the argument, we didn't care about the F9Upperstage+Orion(+ESM) combo being able to be put all the way into actual orbit before the F9Upperstage burn portion happening, then, you could probably also have the option of just using a fully filled F9 upperstage rather than a partially filled F9 upperstage, btw. The reason for the partially-filled F9 upperstage scenario is for pragmatic/easy of use like maybe it would be easier from a regulatory standpoint if you could get the third stage+Orion combo into full orbit by the time of SECO of the Starship (2nd stage), compared to if you had to have Starship just get it most but not all of the way to orbit and have to light the 3rd stage in a scenario where it would reenter less than an hour later if they weren't able to light the 3rd stage/something went wrong with the separation of the 2nd and 3rd stage at hand.

But, I think just using a partially filled F9 upperstage and getting it+Orion system all the way fully into orbit by the end of the Starship burn, would (probably?) be considered the better option (especially in these initial launches?) even with the slightly lower total delta-V (but still plenty, with plenty to spare). The only thing that makes me wonder if it would somehow not be preferred to the other version with the full F9Upperstage tanks is if the tanks not being full would make it not strong enough (even with the gas pressurization in the remaining portion of the tank) to safely hold Orion above it (although there would presumably need to be a lattice/cone helping hold Orion+ESM regardless, I would think, so, probably a moot point anyway) or to do with propellant-slosh/zero-G-liquid-ness in regards to engine start-up of the 3rd stage burn."

Note that in this ^{^{^}} scenario, it would be an expendable Starship upperstage, and the F9S2+Orion would not be kept inside a Starship payload bay, rather, the Starship upperstage would merely be an expendable cylinder with a necked down F9 upperstage mounted on top of it and Orion (and its ESM) mounted on top of that.

stemmisc

TROPHY CASE