NASA managers and engineers evaluating the latest batch of proposals for private spacecraft to carry astronauts to the International Space Station fear their choices ultimately will be limited. There are growing concerns on Capitol Hill that it will be too expensive to back more than one design.

The U.S. space agency received proposals for capsules, a lifting body and perhaps other approaches to transporting humans to and from low Earth orbit. But the House of Representatives is set to consider appropriations legislation this week directing an “immediate downselect” to a single commercial crew design.

In an election year, “immediate” probably means later rather than sooner, perhaps in a lame-duck session after votes are counted. And NASA was working last week to find backing for an amendment removing the quick-selection language before the House vote, scheduled for May 8. Even if that succeeds, budget pressure will work against continuing the Commercial Crew Development (CCDev) competition for federal seed money.

“In a climate of decreasing non-defense discretionary spending, the committee does not believe that the administration's proposed budget runout for commercial crew is sustainable,” the House Appropriations Committee states in its report accompanying the NASA funding bill. The report “directs” NASA to focus funding on a single vehicle, or use a leader-follower approach with a main choice and “a second small award to a back-up partner.” It also orders the use of Federal Acquisition Regulation (FAR) contracts rather than the less-restrictive Space Act Agreements currently in force.

The House vote comes as Blue Origin, the secretive startup funded by Amazon founder Jeff Bezos, revealed some technical details of its entry in the commercial crew vehicle sweepstakes. In an interview with Aviation Week, Brett Alexander, Blue Origin's director of business development and strategy, declined to say whether the Kent, Wash.-based company submitted a bid for the Crew Integrated Capability portion of the NASA competition now in evaluation at the agency.

But Alexander says the company is at work on separate vehicles for two different flight profiles—a suborbital vertical-takeoff-and-landing spacecraft called New Shepherd, and a seven-seat orbital capsule so far known only as Space Vehicle. While the Space Vehicle would fly to orbit on an Atlas V in early flights, Blue Origin plans to build its own partially reusable launch vehicle “several years in the future” for orbital flight. Under development with CCDev funding and money from Bezos, the Space Vehicle would parachute back to Earth. The New Shepherd would return suborbital space tourists and scientific researchers to a powered vertical landing reminiscent of the DC-X and DC-XA testbeds flown by the Defense Department and NASA, respectively, in the 1990s.

Initially, the orbital Space Vehicle will use a solid-fuel pusher-type launch abort system (LAS), positioned in the center of the capsule below the crew. Set for testing later this year to check out its thrust-vector control system, the solid-fuel LAS is designed to be carried to orbit and recovered.

Alexander, a former White House space-policy advisor who later worked as head of the Commercial Spaceflight Federation, says Blue Origin is evaluating the pros and cons of that approach, and may adopt the liquid-fueled pusher technique used by some other CCDev vehicles that allows the propellant to be used in orbit. “We're using the solid for our suborbital demonstration of it,” he says. “For the orbital system for the Space Vehicle, we're trading solids and liquids and combined fuel . . . . We're trading all that in our system requirements review that's coming up next month. That will define those sorts of things.”

Blue Origin has completed more than 180 tests of the Space Vehicle's biconic shape at Lockheed Martin's High-Speed Wind Tunnel Facility in Dallas to validate computational fluid dynamics models of its performance (see illustration). Alexander says Blue Origin engineers chose the biconic shape to add a little cross range over a pure capsule for additional landing options on reentry, without the weight penalty of a lifting body like the planned Sierra Nevada Dream Chaser, another CCDev competitor, or a winged vehicle like the space shuttle. The tests evaluated different versions of the basic shape, as well as trim flaps to optimize transitions from hypersonic flight down to subsonic speeds, when parachutes would deploy for the final touchdown.

The company is also preparing to test the thrust chamber assembly and nozzle of its BE-3 liquid hydrogen/liquid oxygen engine in test stand E-1 at NASA's Stennis Space Center. Alexander said the engine is being developed in-house, as is the turbomachinery for the 100,000-lb.-thrust rocket. Blue Origin has hired a “very talented engine department,” he says, which also developed the peroxide/kerosene BE-2 engine used on a suborbital test that reached 45,000 ft. and Mach 1.2 before it was destroyed over West Texas by range safety officers when it developed flight instability (AW&ST Sept. 12, 2011, p. 39).

The BE-3 will power the reusable first stage of the two-stage rocket planned to launch the Space Vehicle. The upper stage would be a throwaway, while the first stage would return to Earth in a powered vertical landing, Alexander says.

Like the Space Vehicle, Boeing's CST-100 capsule and the Dream Chaser would both be launched at first on the Atlas V, which is gaining software that would trigger a crew-vehicle abort in case of a deadly failure in the rocket after launch. The CST-100 would ride its liquid-fueled pusher abort system a safe distance away from the launch vehicle, and then parachute to an airbag-assisted dry-land 5g touchdown similar to the technique it would use on a nominal reentry from orbit.

The Dream Chaser would use its hybrid-motor pusher escape system to eject from a failing Atlas V, and fly a piloted return-to-landing-site maneuver with a 2g load on the crew.

Space Exploration Technologies Inc. (SpaceX) is preparing to launch the cargo version of its planned Dragon commercial crew vehicle as early as May 10 on its first mission to berth with the ISS. The company has long planned to upgrade the Dragon to carry crew with a pusher abort system for emergency parachute landings at sea. Because of its cargo work under the earlier Commercial Orbital Transportation Services (COTS) NASA seed-money effort, SpaceX probably is in the lead for the crew vehicle as well.

Another possible commercial crew vehicle is the Liberty rocket that ATK and Europe's Astrium are developing with an unfunded Space Act agreement (see p. 21). Boeing and perhaps other companies developing commercial crew vehicles are considering Liberty as a possible lower-cost alternative to the Atlas V (AW&ST April 16, p. 40).

The upcoming House vote probably will set up a conflict for the conference committee that will reconcile the House and Senate NASA spending bills. Language approved earlier by the Senate Appropriations Committee, where Democrats hold the chair, is less specific on the question of commercial crew competition, urging the agency to “ensure that multiple competitors remain, but also . . . be mindful that, faced with a stagnant future budget, NASA should not take on obligations to more companies than can be practically supported.”

The House version would appropriate $500 million for commercial crew development within its $17.6 billion topline for NASA. The Senate bill would spend $525 million on commercial crew, and $19.4 billion on NASA as a whole—including a shift in weather-satellite procurement from the National Oceanic and Atmospheric Administration to the space agency.

Hoping to begin delivering crew to the ISS as paying passengers on commercial space taxis in 2017, NASA requested $836 million as the government's share of commercial crew development. But the House panel noted that the $500 million figure was set in the fiscal 2010 NASA authorization act that President Barack Obama signed.