Originally Posted by
joema
Getting into orbit via airbreathing propulsion has been called "getting to space the hard way". Unlike the casino game of craps, you don't get extra payoff for getting there "the hard way". Rather you want to get there the easiest, simplest way possible. Given current technology, that's probably some kind of a rocket.
You'll note that I did specify that the technology isn't there yet. But as long as we continue to throw away a significant portion (or all) of a rocket every time we use it, space access will remain insanely expensive (currently between $2,600 and $10,000 per pound - and the shuttle was ~ $24,000/lb
)
Something around 75% of the liftoff weight of an orbital capable rocket is oxidizer - get rid of that for the first stage and you can add a whole bunch of hardware to make the thing reusable while still reducing the overall vehicle size and weight. True, the current state of the art for Ramjet/Scramjets is no where near making this viable, but technology marches on. An air breathing launch vehicle that could carry an orbiter to ~120,000 ft./Mach 7 (or better) would mean the orbiter wouldn't
need to be huge to carry the fuel to get into orbit.
As I noted, it's not going to happen in my lifetime - the money and technology are not there. Worse, the will to do things like going to the moon is long gone. But if we're ever going to get to the stage where traveling into space is as routine and commonplace as traveling cross country, that's what it's going to take.