RL-10 Engines Will Power Stratolaunch into Orbit

Several interesting developments suggest the Stratolaunch project is beginning to gain serious traction, marking a new entry into the intermediate class of a launch vehicles left vacant since ULA discontinued production of the Delta II, and SpaceX walked away from the Falcon 5, and its own preliminary involvement in the Paul Allen project.

GenCorp, the parent company of Aerojet Rocketdyne, announced yesterday that it has received a contract for 6 RL10C-1 upper stage engines for the Stratolaunch booster, with each upper stage using a pair of the historic engines. The contract also allows for an additional six additional engines to be provided at a later date.  Contrary to some previous speculation, the air launched booster will not bear the name Pegasus II, but will instead be named Thunderbolt, with the overall launch effort dubbed “Eagles Launch System.”

Taken together with proven ATK solid rocket motors powering the first two stages, the new booster can be expected to derive some pricing advantage due to the impending merger of Orbital Science and ATK.  Paired with an RL-10 based third stage, and what OSC describes as an “EELV compatable” 5 meter payload fairing, the 10,000 lb. to LEO Thunderbolt may provider a further challenge to the most basic version of the Atlas V, the 401, which has previously benefited from a number of NASA orders for which it was overqualified, but was the only booster available nonetheless.

From the press release:

“The design concept for The Eagles Launch System involves the launch of an unmanned rocket dubbed Thunderbolt, carrying a commercial or government payload from beneath the fuselage of a giant carrier aircraft. According to the concept, the carrier aircraft will be powered by six Boeing 747 class jet engines and have a wingspan greater than the length of a football field. Upon reaching a prescribed altitude, the rocket will be dropped from the aircraft, at which point two stages of solid rocket boosters will fire and propel the rocket skyward. Once the solid rocket boosters are expended, two Aerojet Rocketdyne RL10C-1 engines will ignite to ultimately place the satellite into proper orbit.

The RL10C-1 is a liquid-fuel cryogenic rocket engine designed and developed from the RL10 family of upper-stage engines, which have accumulated one of the most impressive lists of accomplishments in the history of space propulsion. The RL10 has helped place numerous military, government and commercial satellites into orbit over the last five decades, and powered scientific space-probe missions to nearly every planet in our solar system. This new application for the RL10 family opens a new era within a commercial venture that will again be a platform for demonstrated reliability and mission success.”

Another announcement related to the Stratolaunch project comes out of NASA, where the Kennedy Space Center has applied for a permit from the U.S. Army Corps of Engineers to fill and drain some forty acres of wetlands immediately surrounding the Shuttle Landing Facility at Cape Canaveral.  The area in question is part of 160 acres overall, and is located at two sites one either end of the strip. If approved, the project will then be transferred to Space Florida in order to develop infrastructure to support Stratolaunch, XCOR and other companies seeking to commercialize the massive runway.