Future of deep-space exploration taking shape in technology work
In an election year, with a “fiscal cliff” looming that could whack 's budget by $1.7 billion, U.S. space officials are not eager to declare a new destination in space for human crews just yet.
But once the post-election dust clears, and Congress decides how to handle the funding-sequestration box it created in lieu of making difficult deficit-reduction choices publicly, work underway here and in other space communities around the nation is likely to give some focus to's next steps into the Solar System.
Engineers atare using a medium-fidelity mockup cobbled together from scrap space hardware to run human-factors tests and equipment fit checks on one of the missing pieces in NASA's human-exploration planning—somewhere for deep-space crews to live. They are working with experts at in Houston, under the leadership of astronaut Alvin Drew.
At the Fifth Wernher von Braun Memorial Symposium here Oct. 15-18, industry and NASA field-center engineers outlined other projects that are beginning to flesh out a notional architecture that would use cislunar space to practice for travel deeper into the Solar System.
“We're looking at volume studies—are the crew quarters going to be the right size, the waste and hygiene compartment, the wardroom, the exercise area—we're looking at all those for this extended stay,” says Paul Bookout, who manages the Marshall portion of the Habitat Systems Project.
Using engineering articles from the International Space Station, museum mockups and a 5-ft. aluminum-lithium cylinder left over from Marshall's shell-buckling knockdown factor recalculations (AW&ST Jan. 3, 2011, p. 53) Bookout and his colleagues have built a notional ISS-derived deep- space habitat in the building where the Apollo Moon buggy was developed. Inside the full-size mockup experts can move walls and structural elements around to figure out the best internal configuration for a habitat that would support a crew of four from an Orion multipurpose crew vehicle for as long as 500 days (see illustration).
The medium-fidelity mockup includes crew quarters twice as large as those available on the ISS, shielded from galactic cosmic rays and solar flares by a “water wall” that doubles as the reservoir of recycled water; a science bay that could also be used to grow plants, and an additive-manufacturing glovebox where astronauts would use 3-D printing to make tools and parts they need, and recycle old tools, food containers and other unneeded material.
The operational concept that is evolving would position the habitat in space, send an Orion crew to dock at one end, and use a propulsion system at the other end, and gravity assists, to move on to more interesting destinations. The second Earth-Moon Lagrangian point (EML2) above the Moon's far side is a particularly attractive location as a starting point for human exploration with an Orion and a deep-space habitat (AW&ST Oct. 8, p. 26).
“This concept was focusing on near-Earth asteroids or Mars,” Bookout says. “Recently it's been more focused on the L2.”
The additive-manufacturing, radiation-protection, environmental control and life-support, and propulsion systems in the mockup are all notional. However, separate work on all of them is ongoing through NASA's Advanced Exploration Systems Program and a variety of efforts funded by the Office of the Chief Technologist (OCT), which was set up to advance the readiness level of technology that will enable future exploration. OCT has drafted “roadmaps” to guide its work, and soon will publish a highly detailed “Strategic Space Technology Investment Plan” (SSTIP), according to Chief Technologist Mason Peck.
“That document will be the culmination of the whole roadmapping activity, and will articulate that strategy down to the point that it's clear what resources will be put toward what projects,” Peck says, adding that he hopes to release SSTIP before the end of the year.
In addition to Orion, which was started under the defunct Constellation program, NASA is developing a heavy-lift space launch system (SLS) to move exploration hardware beyond low Earth orbit. The initial version of the SLS, set to fly humans on a quick sortie into cislunar space in 2021 (AW&ST Oct. 1, p. 44), could deliver about 25 tons to EML2, according to Steve Creech, the SLS strategic development manager at Marshall. That would be enough for an Orion vehicle, but the agency is under orders from Congress to enhance the big rocket's 70-ton capability to low Earth orbit to 130 tons.
To do that, the agency plans a new upper stage powered by the J-2X engine already in development, and advanced strap-on boosters. On Oct. 2 NASA awarded a total of $137.3 million for engineering demonstrations that may feed an eventual contract for advanced-booster development, and William Gerstenmaier, associate administrator for human exploration and operations, said the agency was negotiating with other companies for similar work.
Among them is, which is developing a 1-million-lb. thrust, lox-rich staged combustion kerosene-fueled engine designated the AJ-1E6, according to Julie Van Kleeck, the company's vice president of space and launch systems. Also in the mix is Pratt & Whitney Rocketdyne (PWR), which is working under a subcontract to Huntsville-based Dynetics to use up-to-date manufacturing techniques to build the gas-generator-cycle F-1 kerosene engine that powered the Saturn V as a powerplant for the SLS boosters. Among F-1 components to be built and tested is an integrated powerpack. The company will also demonstrate new techniques for fabricating metallic cryogenic tanks under its $73.3 million contract.
Aerojet is in the process of acquiring PWR, but until the deal goes through “we're still competitors,” says Jim Maser, PWR's president.
In addition to the liquid-fueled rocket-engine work, NASA awarded ATK $51.3 million to conduct risk-reduction demonstrations of composite casing, new nozzle design, and propellant, avionics and control-system development for solid-fuel boosters based on the units it built for the space shuttle.
The work also will examine affordability enhancements, growing out of a value stream mapping exercise at the company's Promontory, Utah, manufacturing facility that ATK and NASA say will cut the cost of the early SLS boosters the company is building by 46% from what they would have cost using shuttle-era manufacturing processes.
While the initial solids will have five segments—a design ATK developed for the terminated Ares I crew launch system—the company's advanced design will revert to the four-segment configuration used on the shuttle.
“We took advantage of the maximum transportable size available to us, and the other elements of the system—the composite cases, which allow for higher internal pressures, and that yields higher performance,” says Charlie Precourt, vice president and general manager of ATK's space launch division. “Fundamentally we wanted to minimize the processing time at the Cape, so you have one less assembly function. Intuitively you can see that you minimize to some extent a failure mode by removing one joint, and then you take advantage of other means to manufacture that and processing that in a more efficient way.”