It took about 11 years to go from Kitty Hawk to the first scheduled passenger flights in 1914. On the other hand, about 40 years elapsed between Gargarin in '61 until Dennis Tito's paid flight aboard a Soyuz in 2001.

The interval from Gargarin to now is 58 years. 58 years from 1914 puts us to 1972. By '72 we had turbofan jet airliners of all the current layouts including 4 under the wings, 2 under the wings, 2 in the tail, and different layouts of 3 in the tail. There had been the ill-fated Comet with 4 in the tail. The Concorde SST had done its first flight already in '69. There has been no comparable advance in space flight technology in the last 58 years.

Since '72 there has been cost reduction and refinement of the jet airliner, but prices also have come down due to higher volumes, more passengers per flight, and a reduction in service.

What is this new propulsion technology that you anticipate?