Coverage of the White Knight Two rollout in Mojave, California, yesterday naturally focused on commercial suborbital flights, Virgin Galactic and Sir Richard Branson, who attracts limelight toward himself in much the same way as a space-time singularity. Let's look at it another way, though.
Northrop Grumman, long associated with sometimes-spooky military space programs, has just rolled out the first stage of a low-cost, flexible small-satellite launch system; or, at least, a step towards one. Northrop Grumman, as of last summer, owns Scaled Composites, and the former TRW's roots are in space technology, largely for military use.
Scaled has been cagey about the actual lift capacity of White Knight Two, but has disclosed that its lift capability is 30 per cent more than the weight of SpaceShipTwo. That number hasn't been revealed, either, but given that the craft is substantially bigger than an X-15, its loaded mass can't be far short of 40,000 pounds. That would suggest that WK2 can lift as much as 50,000 pounds. The QuickReach air-launched rocket, at 72,000 pounds, is designed to deliver a 1,000-pound payload into low earth orbit; so one can guess that a WK2 carrying an expendable staged rocket could handle a 500-pound load.
And in the age of "laptop-technology" satellites, 500 pounds is quite a lot. Israel's EROS-B surveillance satellite delivers 70 cm resolution from a 750-pound package, and technology has moved on since it was designed.
One important aspect of the SpaceShipOne demonstration was that it was an end-to-end test of the technology and systems required for a mobile air-launched rocket. Air launching has lots of advantages. The rocket doesn't have to drive through ten miles of air. The nozzle can be sized to near-vacuum conditions, boosting specific impulse. The launch can take place over water, easing range constraints (like the need to make sure that coastal shipping and falling boosters stay away from each other). The choice of launch point and inclination is almost unlimited. SpaceShipOne showed that this could be done with a relatively simple, inexpensive carrier aircraft and mobile support equipment.
So if the military ever decides what it wants to do with responsive space - quick-reaction reconnaissance of denied areas is one good example - the technology is now there.
Edit: Whack-on-side-of head moment - Northrop Grumman quietly entered the small-satellite business last year with an agreement to market the 650-pound Israeli TecSAR radar imaging satellite to the US government.