DARPA is constantly coming up with new concepts however its most recent might be its most ambitious yet -- excluding of course the plan to build a sentient life-saving robot.
Called the Airborne Launch Assist Space Access (ALASA) program (try saying that all day), the project's objective is to reduce the cost of launching satellites to just a third of current costs.
The most promising launch method is by using a small fighter jet. Not only can the fighter reach the required altitude but by having the option of launching from practically any airfield in the world the team are given an almost limitless launch window, removing the hassle surrounding conventional static rocket launches.
DARPAs plans are mostly focused around the new smaller breed of satellite that can be used for visual observation or for communications.
With the US Navy sending up a number of new spy satellites in recent months the US military is clearly keen to cut down costs while also increasing the amount of tech that's orbiting above us.
At present there are believed to be over 1200 active satellites orbiting the Earth.