Hypersoar - Space Hopping Hyperplane

As the aircraft descends into denser air, it would be pushed up by the increased aerodynamic lift. The engines then fire briefly, propelling the plane back into space. Outside the atmosphere, the engines shut off and the process repeats. In this way, HyperSoar would skip off the top layer of the atmosphere every two or so minutes, like a flat rock skittering in slow motion across the surface of a pond.

Passengers would feel 1.5 times the force of gravity at the bottom of each skip, and weightlessness out in space. The experience would be comparable to being on a swing, although HyperSoar's motion would be a hundred times slower.

Including the ascent and descent portions of a flight, a trip from Chicago to Tokyo (10,123 kilometers) would involve about 18 skips and 72 minutes. To travel from Los Angeles to New York (3,978 kilometers) would involve about 5 skips and take only 35 minutes. (Both flights require a total of about 2,450 kilometers and 27 minutes for take off and landing.)

By popping regularly out of the atmosphere and using the engines intermittently, HyperSoar would use less fuel and also solve a critical problem that plagues other hypersonic aircraft designs - overheating.

Beating the heat
Any object speeding through the atmosphere - airplane, spacecraft, meteorite - will compress and heat the air in front of it. This heat is inevitably absorbed by the surface of the object.

"Heat buildup just kills most designs for hypersonic aircraft," explains Carter. "The hotter the craft gets, the more material engineers add to the airframe to strengthen and shield it. Also, most other hypersonic concepts have trajectories that are strictly atmospheric, and the only way to get rid of the heat is to dump it into the fuel and then burn the fuel in the engines. The problem is, the faster you fly, the more fuel you must carry as a heat sink. Eventually, you end up carrying a significant amount of fuel just as a heat sink, and the engines end up running fuel-rich, that is, burning up more fuel than they really need. That's wasteful in and of itself. Also, more material and more fuel translate to more weight. After a while, the aircraft can no longer carry a decent cargo."