alt Hacker NewsTesla Roadster
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Everyone's focusing on the cold gas thrusters, which of course is very cool, but not actually shocking that it technically could be done (economically is another question).
But can we talk about the just casually driving straight vertical or sticking to the ceiling? I didn't think that would be technically possible for a 1000kg+ car with probably at least 2" of ground clearance.
There's presumably very limited stores of compressed gas, so you might get one hop or a couple 0-60 boosts per charge. But with electric fans, suction is a feature with much longer duration (minutes?), so you could feasibly do the batman driving on the tunnel ceiling past traffic trick.
So this is a really neat technical demo, using spacecraft cold-gas thrusters and guidance hardware/software to do crazy stunt stuff in a car, but what's the relevance to an actual product that can be sold, even as a small-volume exotic? These are pressurized gas thrusters, so either the tanks, valves, and piping take up most of the interior of the car, or it has a low-single-digit number of seconds of thrust before recharge, probably both. Also the tanks for these things tend to use incredibly high pressures and are apt to explode spectacularly in any sort of accident.
This is sort of like demonstrating a car that softens the asphalt in front of it with lasers to get a better grip; difficult, technically impressive, and zero chance that it will ever be allowed on a public road.
Edit: According to this Motor Trend article, it uses a big carbon-fiber pressure vessel at 5500psi, so basically an enormous fragile bomb. And the one that did all the stunts had two of the pressure vessels which would have filled most of the interior.
https://www.motortrend.com/news/tesla-roadster-thrust-system...
I don't want flying cars.
I want clean water. I want a stable climate. I want bees to survive.
This is one of the coolest marketing stunts/demos that I have ever seen. In fact, it's the second coolest, only after SpaceX/Tesla's Starman.
However, the COPV-powered reaction thrusters could shred anyone on the wrong side of the vehicle. Even in the non-invite-only 0 to 60 in .6s version, that is also a problem, correct? Meanwhile:
> Tesla 'Cannot Guarantee' Your Roadster Pre-Order Will Ever Be Delivered
https://insideevs.com/news/812247/tesla-roadster-preorder-de...
I simply won't believe they'll sell a version that leaves the ground until I see someone who obviously isn't working for Tesla with one. I'd be surprised if the FAA didn't have something to say about it. I just don't believe for a second that a stiff wind or a low ceiling or a power line (public road or not) or a very obese driver with nobody in the passenger seat isn't going to turn a very expensive car into a very expensive upside down piece of scrap. SpaceX has had enough explosions resulting from COPVs that I can't imagine these actually getting into the hands of people with more money than sense. It's a compelling marketing gimmick that can't be real.
But practicality aside, you have to be an absolute fool to believe any promises Elon makes at this point. Whether it's the automatic charging cable snake, or your car picking you up and dropping you off at the airport, or renting out your car as a self driving ride share, or your cybertruck also being a boat, or the dozens of other empty promises that he's made, there's just no reason to think he's telling the truth about anything until you can try it for yourself.
So, are we just going to ignore that the man is literally asking for YEARS of deposits aka free loans, for a car that literally might never come to fruition?
This is insanity. How are shareholders still supporting this man?
The maths of the flying is a little puzzling to me.
Back of the fag pack, let’s say it is light for an electric car and weights 1000kg. I’ll also go on a limb and guess the air flow is actually subsonic - 200m/s would make it 0.6 Ma (still insanely fast!). Even then, that requires 50 kg of air every second. Or 40 m^3. Using everyone’s favorite metric, this empties an Olympic swimming pool in 1 minute. It also requires a MW of power. I mean… that’s a lot??? Though admittedly, only about as much as accelerating 0-60 in 1 sec (50% of that in fact). So the flying would draw as much power as accelerating at full throttle.
Power requirements would go down a lot with slower exhaust speed, but then you need to shift more fluid. 40 m^3 already seems like a lot to me.
I get it’s a neat little demo and they have to get SpaceX into the picture somehow, but still I don’t understand how it’s supposed to add up. Also, what do I know - just a humble physicist.
Looks like a sensible turning down of the Cybertruck aesthetic into something that looks good.
That said, the production issues with the Cybertruck mean you’d be a fool to reserve one of these. Let others do it, find out how late it arrives, what glued panels fall off at speed and wait for the inevitable recalls. Tesla has torched their engineering reputation lately and this page is making a lot of promises about revolutionary things.
He promised FSD and an affordable base model for everyone, for close to a decade at this point. Instead he dropped yet another car that's not legal on most roads and doesn't even solve a problem to begin with. Imagine what great things could have been done with the money and resources that went into this.
There are three configurations:
- Performance: road ready, seats two, active aero and a “multi-mode suction system.” 0-60 mph in under 1.6 seconds. Available by reservation.
- Thrust: race ready, seats two, adds rear-mounted cold-gas thrusters. 0-60 mph in under 0.9 seconds. Limited release.
- Rocket: seats one, adds thrusters around the perimeter of the car for upward and rotational movement. 0-60 mph in under 0.59 seconds and a top speed of over 230 mph. Invite only.
Per Electrek: https://electrek.co/2026/10/15/tesla-unveils-cyberfied-new-r...
Mark my words, these thrusters and flying car stunts will eventually be used as a justification to merge Tesla into SpaceX, the same way how they justified space datacenter to merge X.ai onto SpaceX.
There was optimus robots already on Tesla side and inference / r&d funded by x.ai (now spacex).
The livestream has the stunts: https://x.com/Tesla/status/2110788059008819215
I definitely have my issues with Tesla and Elon but this was one of the coolest demos I have ever seen in my life. The engineering needed to do this must have been unbelievable.
This video states that it takes 2–6 hours to charge the compressed air for the cold-gas thrusters. And then you can use it exactly once before you have to recharge it. The journalist calls it “beautifully pointless.”
Okay that's one of the coolest things I've seen in a while since the rockets landing.
Car looks half decent too.
This was 100% precursor to the absorption of Tesla into SpaceX and I’m here for it
https://finance.yahoo.com/markets/stocks/articles/tesla-spac...
As an engineer myself, watching the Hagerty interview [0] was an ...interesting experience.
Every time Tesla's VP of vehicle engineering [0] explains the Engineering of the product by stating that they are "breaking the laws of physics", everything he says is losing a bit of credibility...
Can this be scaled down to a Roomba? Then it would both be more useful at picking stuff up off the floor, and able to recover from falling down the stairs.
Using suction to create downforce is an idea that’s been built for race track usage in the past (and been successful in F1 in the ‘70s), but the near certainty of mortal injury from the system failing (and thus destabilizing the vehicle at high speed) made it unpopular and its incorporation has been very limited (McLaren and Ariel did versions, I think). I’m confused how this has (or will pass) regulatory approval for road use. Is the idea that the driver should only utilize this on a track?
Okay, that's some of the most impressive feats I've ever seen. Congratulations to the engineers!
Love the idea that the kind of person who would still buy a Tesla can now more easily access the fatality rates afforded to the next tier of rich dick who is obsessed with small planes. Go for it, y'all!
Tesla Roadster vaporware edition MK2: now with actual vapor!
I know its marketing but still it's super inspiring to me. Try pulling it off in real hardware. It's incredible.
What's so disruptive on these kind of events is, that companies always used to do development for PR-stunts, or to show off their capabilities and vision for the future, but never at this scale of pure engineering investment.
Drawing a parallel, manufacturers presented rollable mobile devices already a decade ago, modular devices with replaceable components, etc. The archives of Nokia and Ericsson (and others) are full with these kinds of products. Car manufacturers did the same. They presented a vision, not a commitment to a product because there is much more to this than just "being able" to build it.
But it was never economically feasible or sensible to do this at SUCH a scale of engineering cost, and presented with the unrelenting confidence of "this will be yours in two years", despite all the fundamental roadblocks still to overcome.
It appears that this is the most disrupting aspect of their presentations: People are not used to being presented a "vision" of such a scale with so little regards for practical execution.
They like the journey they are taken on, and willingly fill all gaps and doubts with "they wouldn't present this if they didn't think of everything already"
The audience for this must get really scared when the magician cuts the lady in half
I'm sure they'll release this one as soon as the release the Roadster introduced 9 years ago.
This is just Tesla marketing. Usually companies just dump money into marketing campaigns. Musk dumps it into engineering instead.
Remember when they sent one into space? Same thing, everyone in the world is talking about it without spending a single cent in ads.
Doesn’t mean we’re getting flying cars.
Why do car manufacturers brag about hitting 60 mph in 1, 2 or whatever seconds? For a normal person, does this really matter - what is the big deal if a car hits 60 mph in 5 seconds instead of 1? There are more important things like safety, repairability, longevity etc right?
I wouldn't trust promo videos.
For Eg, we have self driving trucks. Nikola admits prototype was rolling downhill in promotional video: https://arstechnica.com/cars/2020/09/nikola-admits-prototype...
Tesla’s History of Faking Demonstration Videos: https://dawnproject.com/teslas-history-of-faking-demonstrati...
This is probably just to hype up the stock. The stock is down 5% (5 days), up 1% (1 month), down ~7% (6 months), down ~20% YTD, down ~16% (1 year). It has a PE of 336 and dwindling YOY sales. Tesla’s U.S. vehicle sales fell approximately 14% to 20% year-over-year through the first three quarters of 2026. Rest of the world, Tesla is not competitive and will probably go down rapidly soon.
https://en.wikipedia.org/wiki/List_of_predictions_for_autono... - Worth a read if you haven't already
It's not a flying car. It's a meme stock marketing stunt. I mean, it looks cool and I enjoyed the video but this stuff is not happening and will not be available, ever, probably.
"This is not a safety-optimized car"
Indeed, even for the demo they did not put a human inside.
IRL I can think of so many failure modes it makes this "car" unpractical for anything but a tech demo.
> Ok, so it actually flies.
For a few seconds. It's a parlor trick. And the flying configuration will not be street-legal.
We don't do politics here on HN, but I wouldn't touch a needle made by one of the companies of this douchebag. I'm talking here as a consumer who might end up on the wrong side of this guy's political ambitions.
The fact that the one that can fly is invite-only makes me wonder if there would be ITAR issues with the guidance mechanisms that they have to put into it.
I'm not saying that there aren't lower hanging fruit reasons why they wouldn't make more of those, but you can see how the guidance necessary to make this move the way that it does could be dual use.
I wonder if Musk is entering the brain rot phase, and Tesla will decline from now on. After all, this is something Tesla doesn't need, a second dud after the Cybertruck. I'm sure the decline will take some time though.
I could have used that when leaving Costco last Saturday.
Does anyone have more info on the cupholders? I need to know it won’t spill my coffee.
Production and other realities aside, I've seen some cool shit in my life and this demo is high up there! Did you guys catch 0.5 mach target top speed? That's 600kmh. It'd better do that flying because there probably aren't any rubber tyres that could endure that before exploding within seconds.
Looks like more hype nonsense to keep excitement going while continuing to delay actually delivering a real product.
Amazing tech demo. I would have liked to see more discussion of the cold-gas thrusters in the earlier Hacker News article. Some people seemed confused and made claims that the demo was a separate "rocket" version that used a combustion technology.
BYD has made the more practical cousin of this, and you can actually buy it. They have a car which jumps over potholes automatically: https://www.youtube.com/watch?v=zIKAn8yDkpA
As much we credit Elon, can we take a moment and credit the amazing engineering feat of the Telsa and SpaceX engineers who have pulled off this feat. Incredible. Thanks for advancing the human race forward.
I have to admit that the only thing I give Elon the title of “Genius” for is his ways of putting on shows to launder more money or get larger loans… this economy is a circus.
This is the company that still hasn't delivered FSD and never will because they won't add Lidar to the cars. They can't even drive Robotaxis at night -- why would they try to fly?
It's also the company that built crap Cybertrucks and the fake humanoid Bots controlled by people remotely.
They will never deliver this. It's an excuse to justify SpaceX rescuing Tesla. Meanwhile, SpaceX is primarily Starlink, a telecom company, masquerading as space exploration and AI.
Anyone know the physics of mach diamonds purely from compressed gas? I'm not a physicist, but I thought one of the key aspects of compressed gas is that it can't expand faster than the speed of sound in that gas -- the speed of sound is literally the limit to how fast it can expand?
Tesla has lost the battery tech, volume EV manufacturing, and humanoid robotics to China (when trade restrictions don't apply). It's time to hype something different.
I feel like a curmudgeon because like yes the demo was really cool, but more from the standpoint that they were willing to do a stunt like that in an industry that is incredibly boring (at least in the US). The engineering behind making a relatively heavy object fly around with thrusters is very well understood at this point, I wouldn't call it "incredible" to rig RCS thrusters on a brick and make it do a barrel roll.
EDIT: I want to make it clear that 1) I'm not talking about the driving upside down thing, and 2) just because I am not sensationalizing the kickflip trick as some incredibly complex endeavor doesn't mean I didn't think it was cool and I'm some kind of hollow, depressed sad sack. The kick flip made me laugh my ass off, but be real. His companies make rockets that can belly flop and land themselves, stream hi res video of reentry using LEO satellite constellations, catch huge boosters in towers, and this is what's blowing your mind?
So, if you crash and the air tank ruptures do you just... die?
Ok, so it actually flies. That was unexpected.
It's an incredible engineering achievement to build in massive fans and rocket engines into a high performance car. It's truly wild.
It's being sold in two modes. One with cold gas (no combustion) seemingly just for extra forwards acceleration (no flying) and one with real combustion rocket engines, the latter was in the video and is "invite only".
Wild that they devoted so much effort to an economically completely infeasible model. I wonder if the combustion version will even break 3 figures sales.
Even just the cold gas variant seems like a nightmare for production, there's a high pressure COPV in that thing and that's gonna make crashes much more.. exciting, and Tesla doesn't have a great record anyways. But very few of these are ever getting sold anyways.