I hate to be the one to burst the Tesla bubble today, but the spectacular “flight” we witnessed at the Roadster reveal needs a little context. The car is carrying around 250kg of compressed air, plus the weight of the tanks, valves and thrusters needed to contain and release it. Based on the published figures, that gives it roughly 1.5–2 seconds of maximum thrust before the system needs to be refilled. In short, it's a gimmick.