THE NEW TESLA ROADSTER CAN LEAVE THE GROUND FOR 3 SECONDS. A MANHATTAN TOWER IS 40 FLOORS. Every New Yorker has the same dream: skip the traffic, go straight up. The Roadster almost sells it. 10 thrusters, 600 liters of compressed air, 2 tons in the air. But it’s a hop, not a flight. The tank empties, and gravity takes over. From a rooftop that’s not an exit. It’s a very fast way down.