Frank Morring, Jr. Washington

Before the dust settles from the post-shuttle shift in human access to space, the U.S. could find itself with a big new high-performance hydrocarbon rocket engine to boost NASA's planned heavy-lift Space Launch System (SLS) off the pad. There is a chance it might even replace the Russian-built RD-180 that carries the United Launch Alliance Atlas V.

A dual-use rocket burning refined petroleum-1 (RP-1), a form of kerosene, instead of liquid hydrogen or solid fuel, might hit the sweet spot in next-generation U.S. space launch needs. It could give NASA enough thrust to build its congressionally mandated 130-metric-ton heavy lifter, while removing Russia from the critical path to launching sensitive national security payloads.

“We know the [Defense Department] is interested,” says Dale Thomas, associate director-technical, at NASA's Marshall Space Flight Center. “They are a little apprehensive about using a foreign-sourced engine on a strategic capability for our nation.”

Thomas helped set up the National Institute for Rocket Propulsion Systems (Nirps) at Marshall to find ways to strengthen the U.S. industrial base in the field. One of the Nirps projects is finding “intersecting interests” for collaboration in rocket propulsion, and large hydrocarbon engines may fill the bill.

“We have to have higher lift capabilities out of the Space Launch System, and it turns out one of the options we are looking at is RP-based engines, which potentially intersect with the core-stage engine for the Atlas V,” Thomas told the Fifth Von Braun Memorial Symposium in Huntsville, Ala., this month.

NASA is in talks with the Air Force about joining the Hydrocarbon Boost Technology Demonstrator program, a relatively low-level Air Force Research Laboratory (AFRL) effort to develop advanced kerosene rocket technology. Among the AFRL contractors on the program is Aerojet, which is developing a 1-million-lb.-thrust, LOX-rich staged combustion kerosene-fueled engine designated the AJ-1E6 that could fill the civil and military roles, according to Julie Van Kleeck, the company's vice president of space and launch systems.

NASA is negotiating with Aerojet to bring the AJ-1E6 into the mix of potential powerplants for the advanced boosters it must develop to raise the SLS from its 70-metric-ton initial capability to the 130 metric tons Congress ordered (AW&ST Oct. 22, p. 34). The talks are complicated by the need for agreement among the Air Force, NASA and the company on how best to proceed, according to Rex Geveden, president of Teledyne Brown Engineering, a Huntsville-based supplier that has an agreement with Aerojet to manufacture components for the new engine.