Tesla's Car Will Leave the Ground and Hover: How the Roadster's 'Cold-Gas Thruster' Technology Is Meant to Work

Electric car maker Tesla has unveiled a new Roadster with astonishing technology. The high-speed car will not only travel at extreme velocity; with the help of special technology it will also be able to leave the ground and hover in the air. Its top speed is more than 230 miles per hour, and it reaches 60 miles per hour from a standstill in less than a second.

The main driving force behind the Roadster's ability to float is "cold-gas thruster" technology modelled on SpaceX. The car's "rocket" version will have up to 10 thrusters. Electric motors will be used to open and close the thrusters.

The way the technology works is striking. In a special tank called a carbon fibre overwrapped pressure vessel (COPV), fitted into empty space in the car, air is stored at extremely high pressure. Without burning any fuel, that air is expelled rapidly through the thrusters, creating an opposing force. By applying force downwards, the car lifts off the ground.

The air storage arrangement in this special version is substantial. Including 400 litres in place of the passenger seat, the tanks will have a total capacity of 600 litres. In other words, the car has had to sacrifice seating for its hovering capability.

Elon Musk says the car will be able to refill its air tanks automatically. According to him, the car is also capable of performing complex manoeuvres, including somersaults.

A recent demonstration reportedly offered a glimpse of that capability. A remotely controlled, driverless Roadster was seen jumping, balancing in mid-air and landing safely after passing over a row of parked cars.

Many questions remain, however. It is still not clear whether the Roadster can fly for long using its thrusters. Because the store of compressed air is limited, the hovering is unlikely to last long.

That also raises questions about how practical or safe it would be on ordinary roads for escaping city traffic jams. The safety rules and regulatory approvals for a car hovering above a public road are also far from settled.

For now, the car is not for everyone. The special version will be available only on an invitation basis, in limited numbers.

All in all, Tesla's Roadster is a dramatic demonstration of where car technology might be heading. How commercially sustainable this marriage of SpaceX rocket technology and the road car proves to be, only time will tell; but the demonstration suggests the idea of the "flying car" has moved from science fiction to the threshold of reality.