Pixel Lunar Lander Makes Progress Despite Challenges

DALLAS, Texas -- John Carmack, video game developer and founder of Armadillo Aerospace, told an attentive audience at the International Space Development Conference Friday that his Pixel reusable rocket is making technical and business progress despite some setbacks at the 2006 X Prize Cup.

Since attempting to win the Lunar Lander Challenge in New Mexico last October, Pixel has flown safely nearly 40 times, Carmack told the audience who attended the ?Armadillo and the Lunar Lander Challenge? panel. While Carmack said he had no intention of marketing Pixel?he considers it a technical dead end?he said that businesses and the Department of Defense have expressed interested in using the vehicle as a sensor platform.

Pixel was the lone participant in the Northrop Grumman Lunar Lander Challenge held last year at the Wirefly X Prize Cup. The NASA-sponsored Challenge was part of the two-day event held October 20-21 at the Las Cruces International Airport in New Mexico. NASA provided $2 million in prize money for the challenge.

For those unfamiliar with it, Pixel is a rather oddly shaped space vehicle. Short and squat, it features a central mast and engine unit surrounded by four fuel tanks: two for liquid oxygen, two for ethanol. Four thin shock-absorber landing legs extend from the bottom of the tanks. This very thinness caused Pixel to fall over after a hard landing in Las Cruces. Despite this, none of the tanks ruptured, and the Armadillo team was able to right the vehicle and return it to flight the next day.

In addition to fixing landing gear and engine duration problems, Armadillo has reduced turnaround times for refueling and servicing the rocket, matching and then beating the servicing records set by the DC-X Delta Clipper in the 1990s.

Carmack announced Armadillo?s intentions to develop a bolt-on capability for the Pixel tank and engine, potentially adding as many as 100 additional engine units to a single vehicle. This would enable the vehicle to reach the border of space, while a smaller upper stage consisting of a second set of bolt-on engines would launch a payload to orbit.

However, this isn?t all that interests Carmack. He also wants to use a Pixel-based rocket platform for ?space jumping.? The person riding the platform would be wearing a spacesuit manufactured by Orbital Outfitters and a parachute. When the passenger reached the correct altitude (over 130,000 feet), he or she would jump off the platform and proceed to beat the world?s high-altitude skydiving record, set by a U.S. Air Force pilot in 1960. ?I can?t believe nobody?s tried to beat that yet,? he remarked.

A self-confessed ?computer geek,? Carmack is incorporating a software-based ?modularity? to Armadillo?s rocket design process. This approach allows the team to develop and test subsystems and components individually and repeatedly rather than testing them all at once in flight. Carmack repeatedly emphasizes the modular approach, as well as the need for repeated testing. ?I expect to crash two or three vehicles with every version,? he said, though admitted that the lessons Armadillo has learned through iterative design have resulted in no crashes for quite awhile.

Carmack is optimistic about Armadillo?s progress, all things considered. He promised more developments and progress in the future, up to and including orbital flight. ?It?s exciting to see how close we?re getting here. It?s getting hard to scoff at our abilities.?

Bart Leahy is a technical writer at Schafer Corporation in Huntsville, Alabama. The opinions expressed are his own.

• NASA?s Road to Moon, Mars Paved With Budget Woes
• National Space Society Conference Kicks Off in Dallas
• VIDEO: Post Mortem on Pixel
• VIDEO: Carmack vs. The Moon
• VIDEO: SPACE.com's Wirefly X Prize Cup Video Archive

NOTE: The views of this article are the author's and do not reflect the policies of the National Space Society.

Visit SPACE.com/Ad Astra Online for more news, views and scientific inquiry from the National Space Society.