Edwards, DARPA explore new C-17 capability
by Christopher Ball
95th Air Base Wing Public Affairs
10/7/2005 - EDWARDS AIR FORCE BASE, Calif. (AFPN) -- Soaring 6,000 feet above the sun-baked California desert, a pair of Edwards aircraft -- a C-17 Globemaster III shadowed by a C-12 Huron observer aircraft -- carried out an unusual mission with an even more unusual cargo recently.
The rear of the aircraft yawned open, and at the prompt of "five, four, three, two, one, green light," the loadmasters released the restraints and a 65-foot rocket slid out the back of the aircraft beginning its descent to the desert floor.
The rocket drop was a test mission -- the first of a series dubbed the Falcon Small Launch Vehicle program. The program is a joint venture between the Defense Advanced Research Projects Agency and the Air Force. It is designed to develop a new method of putting a 1,000-pound payload into low-Earth orbit.
This first test was the successful drop of an inert version of a QuickReach Booster rocket filled with water to increase its weight to 50,000 pounds -- about two-thirds the weight of an actual booster.
To compensate for the difference in weight and the center of gravity, the aircraft was put on autopilot at the moment of the release, said Maj. Landon Henderson, a 418th Flight Test Squadron test pilot.
"Fifty-thousand pounds going out the back is a pretty big change," he said.
Major Henderson said this flight was doubly exciting for him. Not only was the mission “fun,” but it was also his final flight here.
The test vehicle is also the longest article ever dropped from a C-17.
Another unique aspect of this mission was the method of getting the test vehicle out of the C-17. In most airdrops, the cargo is strapped to pallets, and the whole package is ejected from the aircraft.
"For this test, a system of rollers was developed to guide the inert rocket out of the aircraft," said Chris Webber, a 418th FLTS test project engineer. "This was quite an exciting event. It ended up going out very clean ... but there's always that anticipation of the unknown."
The Falcon SLV program is ultimately aimed toward affordable space lift. The current price of launching a rocket payload can be $20 million or more. Completion of the Falcon project should reduce that price tag to less than $5 million.
Dr. Steve Walker, DARPA's program manager for the Falcon SLV, said the developing capability will give U.S. forces a huge advantage because of its affordability and flexibility.
The affordability of the system is enhanced by its simplicity, DARPA officials said. Since traditional rockets launch from the ground, a complicated and expensive rocket nozzle must be used to compensate for altitude variation.
"Because the rocket is launched at altitude, it takes advantage of higher performing and extremely simple nozzles, which can be optimized for the higher altitude condition," Dr. Walker said. "Also, propane fuel can be self pressurized at that altitude, so no turbopumps or pressure feed systems are required to force propellant into the combustion chamber."
Another advantage to launching a satellite by air is the launch location and time is limitless. Currently, rocket launches are dictated by the location of launch facilities and many other factors including weather. By putting the system on a C-17, there is no limit to geographic location, and the aircraft can fly away from or above the weather.
"The Airlaunch rocket can be flown anywhere in the world in any unmodified C-17," Dr. Walker said. "This capability can be used by other services, especially the Army, to put tactical intelligence, surveillance and reconnaissance satellites into low-Earth orbit. These tactical satellites could be used and controlled by combatant commanders, supplying the frontline warfighter with in-orbit ISR capability."
This first test, dropping a mock-up rocket from 6,000 feet, was designed to test the safety of the release system, program officials said. Future drops will be at increasingly higher altitudes, ultimately testing the drop of a live rocket, which will launch at altitude after leaving the aircraft.
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