ATK Aerospace, which will provide the large solid rocket boosters for use on initial versions of NASA’s congressionally mandated Space Launch System (SLS), will have to defend its role starting in 2013 or 2014, the U.S. space agency said Sept. 22.

That is when NASA plans to solicit bids for an alternative side-mounted booster, according to the agency’s preliminary acquisition strategy for SLS. Companies that have expressed interest in the contract include Pratt & Whitney Rocketdyne, Space Exploration Technologies Corp. and an Aerojet-Teledyne Brown team.

ATK Aerospace is providing a five-segmented version of the giant solid-rocket boosters it has provided for years for NASA’s now retired space shuttle fleet. The other companies are expected to offer liquid-fueled engine designs.

NASA plans to issue this year a solicitation for proposals for risk reduction work on the side-mounted booster program.

As expected since NASA unveiled its chosen SLS design back in July, Rocketdyne of Canoga Park, Calif., Boeing Space Exploration of Houston and ATK of Magna, Utah, are in line to retain work awarded to them under the canceled Constellation program, which was intended to replace the space shuttle and return U.S. astronauts to the Moon. SLS is similar to the enormous Ares 5 cargo lifter planned under Constellation.

SLS development is to proceed in phases, the first of which is to produce by 2017 the vehicle’s core stage and side-mounted solid boosters. That configuration will be able to lift 70 metric tons to low Earth orbit. Later SLS configurations will add an upper-stage engine and additional core engines to increase the rocket’s payload capability to 130 metric tons. The first crewed SLS flight is planned for 2021 and will feature the 70-metric-ton configuration.

In the synopsis, NASA affirmed plans to use existing Ares contracts for this work. Rocketdyne will contribute the J-2X engine for the rocket’s upper stage, as it would have for the Ares 5; ATK will contribute five-segment solid- rocket motors; and Boeing will provide the avionics packages for the core and upper stages of SLS.

In contrast with the Ares 5, SLS’s core stage will use a cluster of Rocketdyne-built RS-25D space shuttle main engines. Ares 5 would have used RS-68 engines, the core engine for United Launch Alliance’s Delta 4 expendable rocket.

NASA plans to hold an SLS industry day Sept. 29 in Huntsville, Ala. At that event, the agency will release additional SLS acquisition details and gather feedback from aerospace companies whose Ares contracts must be modified.

NASA also wants to take in feedback from companies interested in the side-mounted booster contract.



NASA Commits To Building Mandated Heavy-lift Rocket