Risk reduction for the advanced strap-on boosters that will be needed to give NASA’s planned Space Launch System (SLS) the 130-metric-ton lift capability to low Earth orbit ordered by Congress will cost as much as $200 million over a 30-month period.
The U.S. space agency on Feb. 14 released its expected NASA Research Announcement (NRA) for the advanced-booster risk mitigation, saying that it will make “multiple awards” for analysis and hardware demonstrations “and anticipates $200 million total funding.”
“These risk-reduction efforts will set the course for the full-scale design and development of this new advanced booster,” said Chris Crumbly, SLS Advanced Booster NRA evaluation team chair. “We’re excited to see what innovative solutions industry will provide as we embark on this new capability — enabling unprecedented missions beyond low Earth orbit.”
The first two SLS flights planned — unmanned in 2017 and, with a crew in the Orion capsule in 2021 — will use five-segment versions of the four-segment solid-fuel boosters that powered the space shuttle. After that, NASA plans to use advanced solid- or liquid-fueled boosters in pairs to increase SLS lifting capability.
Proposals are open to companies cleared to see ITAR-covered technical information on the detailed mass and propulsion properties that NASA is seeking. Deadline for submissions is April 9, and NASA expects to announce the winners in time for an Oct. 1 start date.
In its solicitation, NASA notes that “there are no current booster design solutions that provide the propulsive performance necessary to accomplish the larger payload Design Reference Missions (DRMs) being contemplated for future capabilities.”
In general, the SLS and a four-seat Orion are intended as the U.S. human spaceflight vehicles that will take astronauts beyond low Earth orbit on the way to “the vicinity of Mars” by the mid-2030s, according to Administrator Charles Bolden. The SLS itself would receive $1.8 billion in fiscal 2013 under the agency’s new budget request.
In addition to solid-fuel and liquid oxygen/liquid hydrogen propulsion systems, the agency is interested in boosters that use kerosene as fuel for its high thrust off the pad. Possible engines for that work include the Russian-built RD-180 that powers the Atlas V, an uprated version of Aerojet’s AJ26 modification of the Russian NK-33 engine for Orbital Sciences Corp.’s Antares commercial cargo booster, and even the Rocketdyne F-1 that powered the first stage of the Saturn V Moon rocket.
The boosters must also be able to support the whole weight of the SLS on its mobile launch platform, and fit through the doors of the Vehicle Assembly Building at Kennedy Space Center. That means they can be no taller than 235 ft., and not make the complete SLS vehicle any wider than 67.5 ft. They must also generate no more than 4g acceleration, and a maximum dynamic pressure of 800 lb. of force per square foot, according to the solicitation.
NASA Concept
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