Keeping a floating platform up would be expensive. Gravity is the main force they're fighting. They have used planes in a similar way though: https://en.m.wik

Keeping a floating platform up would be expensive. Gravity is the main force they're fighting. They have used planes in a similar way though: https://en.m.wikipedia.org/wiki/SpaceShipTwo https://en.m.wikipedia.org/wiki/SpaceShipTwo