Greatings All, The story from
It comes down to how much weight you have to takeoff / launch with. Liquid O2 is about 64 pounds per ft^3, where asw liquid hydrogen is on
4 pouns per ft^3. So you take off with only LH2.You then while flying take a portion of hte turbine compressor air and put it in a liquid hdrogen cooled heat exchanger. Presto liquid air. you then centerfugge the N2 contenbt out and you gt 90% pure LOX. Andrews Space and TEchnology did a TSTO design in the mid 1990's and it was impressive: GTOW (gross takeoff weight : 800,000 , a bit bigger than a 747. Orbiter payload was 25,000 pounds. Scale this down a bit and you have a likely design for this SR-71 replacement with a
1-2 man crewed recon craft.As a weapons payload a mass travrling at over 7000 feet/sec needs no explosive and would drill into any hardened target. It would get though the atmosphere in 20-25 seconds. And the orbiter would reach any point on Earth in 90 minutes. No wonder the military likes this.
As a RLV its a bit on the small side, but proves that it can be done.
And in other news folks, Space X is making a space capsule called Dracoon. At about 3.5 meters in diameter and to service the ISS. It will launch on top of a Falcon 9 booster. Lets hope Space X can make it fly . IT will be flying by 2009. t/Space wont be ready by then. in my humble opion.