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.