The US Air Force Research Laboratory (AFRL) has zeroed out funding for the Reusable Booster System (RBS), the space launch vehicle meant to replace the current standard vehicles.
"Pathfinder was cut as the result of an Air Force-wide budget cut," says AFRL. "The funding resources for Pathfinder were cut from the future Air Force budget, not diverted to other programs. The plan for reallocation of Pathfinder personnel is still being developed."
Contracts were awarded in 2011 to three companies - Boeing, Lockheed Martin and Andrews Space Systems -- to study architectures for RBS, with an end-work date in December, 2012 in anticipation that one would be selected to build an airworthy subscale demonstrator, dubbed RBS-Pathfinder.
At least one company, Lockheed, has tested hardware in anticipation of a downselect. Boeing and Lockheed declined to share details of their work to date, and Andrews did not immediately respond to questions.
"Phase I will be concluded in Dec 2012 and the program wrapped up. At that time, all personnel will be redirected to other programs," says AFRL.
RBS involved a reusable, vertical takeoff, horizontal-landing winged first stage that would carry an expendable second stage to suitable altitude, launch the rocket and fly back to land on a runway. The vehicle was meant to replace the evolved expendable launch vehicles (EELV), the Delta IV and Atlas V, with a vehicle that cost half as much to fly.
A recent report from the National Research Council advised against building RBS on cost grounds, but encouraged peripheral research in the hopes of bringing costs down.