WASHINGTON — Astrobotic Technology Inc., a Pittsburgh firm vying for the $20 million Google Lunar X Prize, has payload accommodations to spare on the Falcon 9 rocket it has reserved for a planned 2012 Moon shot.

Astrobotic is looking for customers willing to pay $1.5 million per kilogram plus a $250,000 payload integration fee to hitch a ride to the lunar surface with the 70-kilogram robotic rover the company wants to send to the Apollo 11 landing site to transmit high-definition video back to Earth.

Previous plans called for launching the Red Rover Tranquility Trek mission on an unnamed rocket with roughly a tenth of the Falcon 9’s lift, but the low cost offered by such vehicles came at the expense of spacecraft mass margin.

“We were locked in a struggle to shave grams off our design in order to fit into that constrained launch capability,” Astrobotic President David Gump said in an April 5 interview.

He cited as an example the lengths to which the company went to find a lightweight alternative to the 1-kilogram metal wheels it had planned to use on the rover.

“We worked with [tire manufacturer] Michelin to come up with essentially fiberglass wheels that weighed 200 grams. We just couldn’t come up with enough innovations like that to get some margin into our design,” Gump said.

For Astrobotic, the cost of miniaturization was quickly eroding the cost advantage of going with a smaller rocket than the Falcon 9, the unproven medium-lift rocket that Space Exploration Technologies (SpaceX) is marketing at prices starting at $51.5 million to place a 4,500-kilogram payload into geostationary transfer orbit. Gump said SpaceX asserts the Falcon 9 can deliver about 2,400 kilograms to an Earth-escape velocity.

“With the Falcon 9, we have the freedom to choose from among many [component] suppliers, for one thing,” Gump said. “In trying to miniaturize everything, the choices in terms of what components you can use … often comes down to one supplier because you have to use the absolute lightest versions. Whereas if you have some room to breathe … you can cut your costs significantly because you can choose from among any number of suppliers.”

The bigger rocket also gives Astrobotic the opportunity to bring in $160 million or more in additional revenue by selling accommodations for government or private-sector payloads. Gump said Astrobotic has 109 kilograms of payload capacity available on the Falcon 9. The rover itself can accommodate up to 20 kilograms, with the balance of the capacity available for payloads mounted to the lander. About 5 kilograms of capacity already has been reserved by Celestis Inc., a Houston-based company that operates a space burial service for cremated remains.

Astrobotic announced its dramatically expanded hosted-payload opportunity in mid-March and set an April 30 deadline for potential users to say how they would use the capacity. The company recently presented its mission concept to the NASA-chartered Lunar Exploration Analysis Group and plans to attend the Global Lunar Conference in Beijing May 31-June 3.

Development of the Red Rover is being led by Astrobotic Chief Technologist William “Red” Whitaker, a research professor at Carnegie Mellon University’s acclaimed Robotics Institute just two blocks from the company’s offices.

In the two years since Astrobotic formed to pursue the Google Lunar X Prize purse, the company has put about $3 million into mission development, the majority of which has flowed through Carnegie Mellon, a key partner. The company is completing fabrication of its third rover prototype, one that incorporates a new asymmetrical design that Gump said goes a long way toward solving “the No. 1 technical challenge of the lunar robot, which is not cooking yourself to death during the daytime.”

One side of the vaguely pyramid-shaped rover is covered with solar cells that always point toward the sun; on the other side is a very large radiator that always faces toward black sky. To maintain this orientation, the four-wheeled rover is designed to “tack like a sailboat” in order to go north or south, Gump said.

Astrobotic recently tested a new battery from Watertown, Mass.-based A123Systems that Gump said should make it possible for Red Rover to survive the Moon’s freezing two weeks of night and resume roving for at least part of another two weeks of lunar day. This summer, Astrobotic also expects to conduct its first demonstrations of how Red Rover will “talk as it explores,” Gump said.

“We’re going to be creating a social robot, one that can Twitter, post updates to Facebook and upload photos to Flickr,” Gump said. “In the past, NASA probes have had a human being behind the curtain pretending to Twitter on behalf of the robot.”

Red Rover, in contrast, will be designed to report its status in plain language via various social networking applications and transmit photos without a person in the loop, Gump said.

For now, a lot of Astrobotic’s focus is on fundraising. The company has yet to make a down payment on its launch vehicle. Gump said that will happen “as soon as we get the next chunk of investor money or customer money.”

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...