News · New this week
Tesla Roadster flying car demo: fans and cold gas thrusters
Two tricks explain the Roadster stunt, fans that pin the car to the road and compressed air jets that spin it and land it.
On 15 October, Tesla showed the new Roadster at SpaceX's test site in Texas. The car drove up a curved wall, went upside down, did a flip and landed. Someone in your group chat has probably already called it a flying car, something drone-like.
It didn't fly. It used two separate tricks, and each one is simple enough to explain with a kitchen appliance.
Trick one, fans that pull the car down
Fans under the car pull air out from beneath it. Think of a vacuum cleaner. The car sits on the road and sucks.
Along the edges there are seals. They work like the rubber ring on a pressure cooker, and they stop air from leaking back in underneath.
With less air under the car, the air outside pushes the car onto the road. That push is called downforce. Tesla says it's strong enough to keep the car stuck even when it's upside down. That claim is what makes the wall climb make sense. The car is held against the surface, so which way is up matters a lot less.
Trick two, cold gas thrusters
Gripping the road explains how the car stays on a surface. It doesn't explain how the car spins in the air, which is the part that looks like flying.
For that, the car carries a tank of compressed air. The air is let out through small jets. You've seen the same thing with a balloon. Let go of it and it shoots the opposite way from the escaping air. Here, the car goes the opposite way from each jet.
Those short pushes are what rotated the car and set it down again. The name for this is a cold gas thruster. There's no fire involved, just gas coming out of a nozzle.
Nobody was driving
There was no driver in the car. A computer ran the stunt, and it was programmed ahead of time. So nobody was steering through the flip.
Musk says you'll be able to buy the car in 2028. That's his claim about production, and the demo doesn't prove it either way. What the demo gives you is two tricks to understand, one that keeps a car stuck to a surface and one that spins it and sets it down.
What to take from it
Next time a clip claims a car flew, ask what is holding it and what is moving it. Here the answers are downforce from fans and seals, and cold gas thrusters. Send this to the friend who said they'd be flying over Silk Board soon, and see whether they still want the drone version.
The footage in the reel is from Tesla.
