NASA has selected for contract negotiations six proposals to reduce risk and cost on future advanced boosters for its Space Launch System (SLS) heavy-lift rocket.

The proposals are for engineering demonstrations to support the transition of the SLS from its initial 70-metric-ton lift capacity, set to debut in 2017, to an eventual 130-metric-ton capability. Up to $200 million will be distributed among the teams chosen for formal contracts. Awards are expected in October, with funded efforts to last 30 months, and feed into the competition for the SLS advanced booster, currently planned for 2015.

The initial SLS configuration will use two five-segment solid rocket boosters derived from the space shuttle’s boosters. But the evolved SLS needs an advanced booster significantly more powerful than any current U.S. liquid or solid boosters.

Proposals selected for contract negotiations are:

• “Subscale Composite Tank Set,” Northrop Grumman Systems Corporation Aerospace Systems.

• “Full-Scale Combustion Stability Demonstration,” Aerojet General Corp.

• “F-1 Engine Risk Reduction Task,” Dynetics Inc.

• “Main Propulsion System Risk Reduction Task,” Dynetics Inc.

• “Structures Risk Reduction Task,” Dynetics Inc.

• “Integrated Booster Static Test,” ATK Launch Systems Inc.

Dynetics is partnered with Pratt & Whitney Rocketdyne (PWR) to repurpose Rocketdyne’s Apollo-era F-1 engine for the SLS. A relative newcomer in the space launch arena, Dynetics’ proposals are geared towards reducing risk on critical booster components.

The company’s F-1 risk reduction tasks would include gas generator and powerpack evaluations, according to Steve Cook, Dynetics’ director of space technologies and NASA’s former Ares program manager. The company’s main propulsion system risk-reduction proposal would involve cryogenic valve and line-in valve demonstrations, and the structures proposal would demonstrate low-cost cryogenic tank manufacturing approaches.

“Those risk reductions are focused heavily around affordability ... because a big deal on the Space Launch System is affordability, while also giving NASA additional performance margin above their 130-metric-ton requirement,” Cook tells Aviation Week. “With an F-1 based approach, we get significant performance enhancement beyond the 130 [tons], on the order of 20 metric tons.”

If chosen for formal contracts, Dynetics demonstrations would take place variously at company facilities, NASA’s Stennis Space Center in Mississippi and Marshall Space Flight Center in Huntsville, Ala., where Dynetics is headquartered. With PWR as a partner, Dynetics also plans to throw its hat in the ring as a prime in the future competition to build the advanced booster for SLS.