NASA has selected two suborbital resusable launch vehicles to provide four flights for microgravity experiments. Masten Space Systems of Mojave, Califonia has been selected for its Xaero vehicle while Armadillo Aerospace of Heath, Texas will provide rides on its Super Mod. In support of its efforts, Masten has just signed a $400,000 contract with Space Florida to perform a series of demonstration flights.

The space agency put out a combine call for experiments and suborbital flight services in December as a part of its Flight Opportunities program designed to foster development of the commercial reusable suborbital transportation industry along with providing more opportunities for researchers to fly experiments in microgravity.

Two of the four payloads will fly both on suborbital services and on a commercial Zero-G aircraft that flies in a series of parabolic arcs to simulate weightlessness. A coalition from Embry-Riddle Aeronautical University, NASA Kennedy Space Center, and United Launch Alliance (ULA) will fly an experiment looking at on-orbit propellant refueling while Made in Space, Inc. will demonstrate 3D printing technology designed for building everything from spare parts to structures and spacecraft in space.

Both technology experiments have implications for long-term operations in space. In-orbit refueling is a technology NASA wants to master while being able to dial-up 3D parts on demand in zero-G would provide an on-demand spare parts capability should something break on the International Space Station or on other missions beyond low earth orbit.

Two experiments unique to the first round of suborbital flights are a precision landing technology demonstration – dubbed PLANET – sponsored by Draper Labs out of Cambridge Mass and NASA Johnson Space Center and Johns Hopkins APL electromagnetic field measurements experiment specific to suborbital launch vehicles.

NASA expected the selected experiments to be flown on test flights by Masten and Armadillo in 2011, with more projects to be booked on an on-going basis as researchers continue to apply for flight slots under the Flight Opportunities program.

Masten will demonstrate its reusable suborbital craft at Launch Complex 36 at Cape Canaveral Air Force Station. The VTVL (Vertical Takeoff Vertical Landing) vehicle will complete multiple flights and serve as a pathfinder for helping Space Florida working with VTVL vehicles. In exchange, Space Florida plans to cover rage costs and facilities upgrades at the launch complex.

While not explicitly named in Masten's press release, it is likely the Xaero vehicle will be used for the VTVL flights. Based on a vehicle design that won two Lunar Lander Challenge competitions, Xaero is expected to carry a 10 kilogram payload up to 30 kilometers, according to a blog posting in Parabolic Arc,  with a total flight time of about 6 minutes.

Armadillo Aerospace has a friendly rivalry with Masten, having competed against them in the Lunar Lander Launch Competitions with its VTVL vehicles, with Super Mod winning one Lunar Lander Challenge competition. The company has a colorful background, with founder John Carmack making his fortune as a founding member and technical director of id Software -- the company known for DOOM and Quake computer games.