Pixel Lunar Lander Makes Progress Despite Challenges

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

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

Pixel wasthe lone participant in the Northrop Grumman Lunar Lander Challenge held lastyear at the Wirefly X Prize Cup. The NASA-sponsored Challenge was part of thetwo-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 thoseunfamiliar with it, Pixel is a rather oddly shaped space vehicle. Short andsquat, it features a central mast and engine unit surrounded by four fueltanks: two for liquid oxygen, two for ethanol. Four thin shock-absorber landinglegs extend from the bottom of the tanks. This very thinness caused Pixel tofall over after a hard landing in Las Cruces. Despite this, none of the tanks ruptured, and the Armadillo team wasable to right the vehicle and return it to flight the next day.

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

Carmackannounced Armadillo?s intentions to develop a bolt-on capability for the Pixeltank and engine, potentially adding as many as 100 additional engine units to asingle vehicle. This would enable the vehicle to reach the border of space, whilea smaller upper stage consisting of a second set of bolt-on engines wouldlaunch a payload to orbit.

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

Aself-confessed ?computer geek,? Carmack is incorporating a software-based?modularity? to Armadillo?s rocket design process. This approach allows theteam to develop and test subsystems and components individually and repeatedly ratherthan testing them all at once in flight. Carmack repeatedly emphasizes themodular approach, as well as the need for repeated testing. ?I expect to crashtwo or three vehicles with every version,? he said, though admitted that thelessons Armadillo has learned through iterative design have resulted in nocrashes for quite awhile.

Carmack isoptimistic about Armadillo?s progress, all things considered. He promised moredevelopments 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 scoffat our abilities.?

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

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• VIDEO: Post Mortem on Pixel
• VIDEO: Carmack vs. The Moon
• VIDEO: SPACE.com's Wirefly X Prize Cup Video Archive

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