Frontier tech · work it out yourself
Tesla's new Roadster jumps on gas jets: why would a car need thrusters?
The Duowenwen team · Updated
What happened
On October 15, 2026, Tesla unveiled the second-generation Roadster.
The event took place at SpaceX's rocket test site in McGregor, Texas, near Waco. It was planned for October 1 but was pushed back by rain.
Nobody was inside the car during the demo. Here is what it did, in order:
- Floor fans sucked the car onto a curved ramp, and it drove up until it was upside down.
- Cold-gas thrusters fired and the car took off. Tesla developed the thrusters together with SpaceX.
- The car did a full roll in the air and flew over a row of Teslas, a Semi truck among them.
- Then it landed.
Musk called it "the best of the last of the human-driven cars." He also said it is "not necessarily a safety-optimized car."
Musk said production starts in 2028 at Giga Texas in Austin. That date has slipped many times. The first target was 2020.
Why would a car need a rocket?
A car speeds up by pushing the road backward with its tires. The road pushes the car forward.
Friction caps that push. On a normal surface, tires can give at most about 1.2–1.5 g of acceleration.
g is the acceleration of gravity, about 9.8 m/s². At 1 g, your speed grows by 9.8 m/s every second.
0–60 mph means going from standstill to 26.8 m/s. Tesla claims the Thrust version does it in 0.81 seconds.
Average acceleration = 26.8 ÷ 0.81 ≈ 33 m/s², or about 3.4 g.
That is more than twice what tires can do. The thrusters must cover the gap by blasting gas backward to push the car forward.
The floor fans pull the car down, so the tires grip harder. Tesla hasn't said by how much.
What is a cold-gas thruster?
A cold-gas thruster burns nothing. It lets high-pressure gas out through a nozzle. The gas goes backward, so the car goes forward. That's Newton's third law.
The Roadster uses nitrogen (N₂). These figures come from Top Gear's interview with Tesla engineers, as reported on Wikipedia.
- Thrust version: one 200-liter composite overwrapped pressure vessel (COPV) at about 10,000 psi, roughly 690 bar. It fills the trunk and feeds four rear nozzles.
- Rocket version: a second 400-liter tank sits where the passenger would, for 600 liters in total. Ten nozzles are spread around the body.
- An electric pump on board refills the tanks. A full fill takes 2–6 hours.
One bar is about one atmosphere, so 690 bar is roughly 680 times the air pressure at sea level.
Specific impulse measures how much push you get from each kilogram of propellant. It is given in seconds. Multiply it by 9.8 and you get the exhaust speed.
Cold nitrogen manages about 60–75 seconds, an exhaust speed of about 600–730 m/s. Rocket engines that burn fuel reach about 300–450 seconds.
Cold gas needs no ignition, so the hardware is simple. The price: the same mass of propellant delivers only a fraction of a rocket engine's impulse.
How long can it fly, and how hard does it push? (estimate)
Tesla hasn't published a thrust figure. What follows is our order-of-magnitude estimate from public numbers, not official data.
According to Top Gear, one tank lasts about 5 seconds. We use that burn time.
- Weigh the gas. Ideal gas law: m = PV ÷ (R·T). For nitrogen R = 296.8 J/(kg·K); room temperature T ≈ 293 K. 200 liters at 690 bar gives about 159 kg.
- Correct it. At that pressure nitrogen is harder to squeeze than an ideal gas. The compressibility factor Z is about 1.5–1.6, so the real mass is about 100 kg. 600 liters holds about 300 kg.
- Find the flow rate. 100 kg over 5 seconds is about 20 kg per second.
- Find the thrust. Thrust F = flow rate × exhaust speed ≈ 20 × 690 ≈ 14,000 N, about 1.4 tonnes-force.
- Compare it with the car's weight. A 1,700 kg car weighs about 16,700 N. The thrust-to-weight ratio is about 0.8–0.85.
The ratio is below 1. The thrust can't hold the whole car up, so it can't keep flying. It can only hop.
In the demo, run-up speed, the floor fans and the thrusters worked together.
This estimate assumes the gas flows out at a steady rate. In reality the tank pressure falls as it empties, and the thrust falls with it.
Run the numbers
Drag the sliders to change the tank, pressure, exhaust speed, burn time and car mass. Everything is computed in your browser. The results are estimates, not Tesla's figures.
① Estimate the thrust
- Nitrogen mass · ideal gas
- 159 kg
- Nitrogen mass · corrected, Z≈1.5
- 106 kg
- Mass flow ṁ = m ÷ t
- 21.2 kg/s
- Thrust F = ṁ × v
- 14,600 Nabout 1.5 tonnes-force
- Thrust-to-weight F ÷ (M·g)
- 0.88
Thrust is less than the car's weight. It can't hold the car up; it can only help it hop.
Z≈1.5 is the value at 690 bar. At lower pressure Z gets closer to 1. We correct by 1.5 throughout, so at low pressure the mass comes out too small.
Assumes the whole tank flows out at a steady rate and all thrust points forward. In reality tank pressure drops as it empties, and thrust drops with it.
② How hard must it accelerate for 0–60 mph?
Tires can't do this. Some other force has to push the car forward.
Even if the tires give their best 1.5 g, 31,300 N is still missing. The thrust estimated above is 14,600 N, enough to cover about 47%. Try a shorter burn time: the same gas leaves faster, so flow and thrust both go up.
The floor fans pull the car down so the tires grip harder. Tesla hasn't said by how much, so this leaves it out.
Three versions
The reservation page lists three versions. Tesla hasn't announced a price for any of them.
| Performance | Thrust | Rocket | |
|---|---|---|---|
| Thrusters | None | 4 rear nozzles | 10, front, rear and sides |
| 0–60 mph | Not listed separately (Teslarati: under 1.6 s) | 0.81 s (claimed; 0.85 s in another place) | Under 0.59 s (claimed) |
| Seats | Normal | Normal | Single seat; a tank replaces the passenger seat |
| Reservation | $50,000 | $250,000 | Invitation only |
| Price | Not announced | Not announced | Not announced |
All of these 0–60 times are Tesla's own claims. Nobody has timed them independently.
What all three share
- Two rear motors, rear-wheel drive (Top Gear). In 2017 the plan was three motors and all-wheel drive.
- More than 1,000 kW, about 1,341 hp.
- Claimed top speed over 230 mph. Top Gear says the first cars do 214 mph, with a 330 mph version planned.
- Claimed range over 300 miles. Top Gear says 310–320 miles.
- Target curb weight under 1,700 kg. Claimed cornering over 2 g.
- Every version has floor fans and an active rear wing to press the car down. That is how it stayed on the ramp upside down.
- The cold-gas thrusters are for off-road and track use only, not a road feature (Top Gear).
What we still don't know
- How much thrust the jets give, and how it changes during a burn.
- How much the tanks and pump weigh, and how that affects handling. Motor1 notes Tesla didn't explain this.
- Nobody has timed 0–60 independently. Nor has anyone explained the gap between 0.59 s and 0.81 s.
- The flying feature isn't approved for the road.
- In 2025, Electrek reported on a Tesla patent. It argued that the patent doesn't fit the claim that the car can fly.
- The price of any version.
Sources
- Wikipedia: Tesla Roadster (second generation), citing the Top Gear engineer interview, TechCrunch, Wired and Car and Driver
- Aviation Week, 2026-10-16: Tesla demos flying Roadster powered by SpaceX cold-gas thrusters (paywalled; we read the summary only)
- NBC News: Elon Musk shows flying Tesla Roadster after years of delays
- Motor1: Tesla Roadster stunt, 2028 production
- Teslarati: Tesla Roadster specs and configurations (the three versions)
Tesla's event and reservation page are the primary sources. We didn't read them directly; the claims on this page come from the reports above. Numbers marked as estimates are our own arithmetic.