Yes but they will be cheaper still. the follow on to the ansari prize will be for orbtal vehicles destined to service space hotels and private outposts.
Meanwhile check this out. This might be a future impulse engine in real spacefaring cruisers:
September 28
Sound Waves Might Power Spacecraft
Future deep space probes may be energized by powerful sound waves, akin to claps of thunder we hear on Earth when lightning thermally expands the atmosphere.
Researchers at Los Alamos National Laboratory and Northrop Grumman Space Technology have teamed to design the traveling-wave thermoacoustic electric generator. The engine has the potential to power space probes to the furthest reaches of the universe.
The traveling-wave engine works by sending helium gas through a stack of 322 stainless-steel wire-mesh discs called a regenerator. The regenerator is connected to a heat source and a heat sink that causes the helium to expand and contract.
This novel engine is a modern-day adaptation of the 19th century thermodynamic invention of Robert Stirling -- the Stirling engine -- which is similar to a steam engine. In this space-rated replay, heated air instead of steam drives a piston.
Oscillating sound waves in the traveling-wave engine drive the piston of a linear alternator that generates electricity. And since the only moving component in the device besides the helium gas itself is an ambient temperature piston, the device possesses the kind of high-reliability required of deep space probes.
NASA funded the traveling-wave thermoacoustic electric generator research.
Topic: Virgin Space Lines; VSS Enterprise (Read 1233 times)