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Editorial: 鈥� New race to the moon: The legal has landed鈥�

Gallery: 鈥�The robots in Google鈥檚 race to the moon鈥�

On your marks, get set, lift-off: everyone from garage inventors to aerospace magnates is racing for the Lunar X Prize. New Scientist surveys the field

UNDER the harsh sun, shining out of a pitch-black sky, a four-wheeled rover zigzags across the cratered lunar surface. It seems to be looking for something. Every so often it stops to sift through the dusty soil, before moving on again. But one of these pauses lasts longer than the rest. Suddenly, an antenna extends skyward, pointing at the fat blue marble 385,000 kilometres away. Humans back on Earth who subscribe to Red Rover鈥檚 Twitter feed get the news within seconds: 鈥淲e鈥檝e found water!鈥�

That, at least, is the script of David Gump鈥檚 dream. He is part of a team that is building Red Rover and plans to send it to the moon. He is confident that it will not only kick-start a new era of lunar exploration, but will also win his team a $20 million prize in the process.

That money is the top award on offer in the Google Lunar X Prize (GLXP), money that the internet giant is putting up as a way of galvanising an entrepreneurial 21st-century space race. By the standards of space exploration this may not be big bucks, but it has been enough to motivate 29 entrants from around the world. They are a diverse bunch, including teams of scrappy young hackers, buttoned-up defence contractors, and veterans of the Soviet space programme. There鈥檚 even a team of self-styled wizards.

The top prize will go to the first to land a robotic rover on the moon, drive or fly it at least 500 metres from its landing point, and send video, still images and data to Google鈥檚 computers back on Earth. The winner will not only have unique bragging rights, but also a proven method for extracting profitable information about the moon.

Apart from a handful of deliberate crash landings, neither human nor machine has graced the moon鈥檚 surface since 1976. The new missions could revive long-abandoned dreams. The moon鈥檚 far side, for example, offers unique opportunities for observing the universe. Because it is permanently shielded from the noise of the world鈥檚 radio traffic, it would be an ideal site for instruments designed to detect the faint remnants of the universe鈥檚 formation. Other benefits could also flow from a moon landing. Any water that can be extracted from the lunar surface could be used to fuel voyages to Mars and beyond. The moon could even be home to the first permanent human settlements outside Earth.

The neglect of the past 35 years is scarcely surprising, given the ruinous cost of past lunar missions. At its peak, the Apollo programme that took men to the moon was consuming , or 5.3 per cent of the US federal budget. The Soviet Union鈥檚 Luna programme was no less of a budget-buster. That era of vast projects masterminded by national space agencies is now over. Even NASA is discovering that private space entrepreneurs can innovate far more cheaply, and that the offer of prize money can help to get them started.

The earliest of the prize competitions, the $10 million Ansari X Prize, called for the private development of a reusable piloted space vehicle. It was won in 2004 by Scaled Composites, a company based in Mojave, California, with its SpaceShipOne craft 鈥� but its winnings were dwarfed by the estimated $25 million it spent on development and testing. This highlights a problem with competitions like the GLXP. Even for a successful entrant, the prize money alone may not cover development costs. In fact, according to William Pomerantz, who runs the GLXP, on average, the teams will need to spend about $60 million.

So the GLXP aims to encourage projects that can also profit from an existing market: the hunger of organisations such as NASA and the European Space Agency (ESA) for data. For those who fail to win the top prize, there is a $5 million prize for the runner-up, as well as a smattering of prizes totalling $5 million for advances such as travelling significantly more than 500 metres or finding evidence of lunar water (see 鈥淲ater from a stone鈥�). NASA is supporting the GLXP, and has advised Google on the competition rules.

Last year, NASA itself promised a total of $30 million through its Innovative Lunar Demonstrations and Data (ILDD) programme to six projects to collect data that can be used for future robotic and human lunar missions. As it happens, all the winners are also GLXP contenders. But even for outfits that did not receive any of the ILDD funds, the programme signposts the existence of a commercial market that GLXP contenders will be able to tap into long after Google has dispensed its prize money.

The Google contest has pulled in talent from all corners of the world. By the time the contest鈥檚 sign-up window closed at the end of 2010, 33 teams had signed up, of which 29 are still in the running. They come in all shapes and sizes. Red Rover鈥檚 creator, a company called Astrobotic, has partnered with two powerhouses: initially with Raytheon, a defence contractor based in Waltham, Massachusetts, and currently with Carnegie Mellon University in Pittsburgh, Pennsylvania. At the other end of the spectrum is FREDNET, a loose and far-flung collaboration of engineers and tinkerers working in their garages at weekends. Team Selenokhod includes veterans of the Soviet Union鈥檚 Luna programme, whose robots brought back lunar samples in the 1970s.

Agony of choice

No matter what their pedigree, all of the teams have their work cut out for them. First they will need to figure out where on the moon to land their rovers. As lunar water is believed to be concentrated at the poles, most of the competitors are focusing on these regions. Then there鈥檚 the question of how to land. C-Base Open Moon, a consortium of hackers based in Berlin, Germany, is proposing a hard landing cushioned only by air bags, inspired by the successful landings on Mars by the rovers Spirit and Opportunity. Other teams will opt for a soft landing using pulsed thrusters and impact-absorbing crushable honeycomb pads.

Having arrived safely on the moon, the next task will be to navigate across its surface. The proposed methods reflect the teams鈥� diverse backgrounds. Astrobotic鈥檚 Red Rover is a wheeled design not fundamentally different from that used for NASA鈥檚 Mars rovers, except that it has four wheels rather than six. Its pyramidal body is covered in solar panels and crowned with a pair of camera sensors, making it look as though it has a small head with two eyes. C-Base Open Moon has come up with something less conventional: a two-wheeled contraption that calls to mind an 18th-century artillery piece. Tucked between its two massive wheels is an assortment of solar panels, cameras and other equipment.

Some competitors are doing away with wheels altogether. Take the lander Talaris, for instance, the brainchild of the Next Giant Leap (NGL) consortium of Boulder, Colorado, which includes scientists from the Massachusetts Institute of Technology and the Charles Stark Draper Laboratory based close by in Cambridge. The lander will use pulsed thrusters to bound across the lunar surface in leaps of up to 5 kilometres. By abandoning the tried-and-tested technology of wheels and solar-powered motors, NGL hopes to have come up with a means of locomotion that could be used by landers on future missions to Mars or an asteroid.

Whatever technologies are chosen for locomotion and for the lander鈥檚 sensors, they will have to contend with the moon鈥檚 extremely harsh environment. The dust that covers the lunar surface is both sticky and abrasive, and has been shown to cause a surprising amount of damage. Another hazard is the wildly varying temperature of the moon鈥檚 surface: at the equator it rises to 120 掳C but plummets at night to -150 掳C. Red Rover鈥檚 solar panels will face the sun at all times, not only to maximise the power they produce, but also to shade the vehicle from the direct heat of the sun. Gump says the company is fitting its moon buggy with components that can survive a complete shutdown during the two frigid weeks that constitute one lunar night.

All this assumes, of course, that the contestants can find a way to get their lander to the moon without a launch vehicle of their own. The obvious option is to pay someone else to get it there. As well as established launch operators NASA, ESA and the Russian space agency Roscosmos, there are emerging private companies like SpaceX, which scored recent successes with its Falcon 9 rocket. Launch costs are typically at least $10,000 per kilogram, so hauling even a modest moon buggy of a few hundred kilograms could cost millions 鈥� enough to bankrupt at least half the teams.

Pomerantz says his organisation has made a deal with SpaceX that it will waive any profit from launching GLXP missions. And for anyone prepared to launch from Florida soil, the state has agreed to add a further $2 million to any prize money they win. Several competitors, including Rocket City Space Pioneers, have discussed cooperating in a single launch, and then releasing their missions simultaneously. Wendell Mendell of NASA鈥檚 Lunar and Planetary Exploration Office says NASA, ESA or Roscosmos might even consider flying GLXP missions for free. Now wouldn鈥檛 that be an ironic start to the brave new world of privately funded space exploration.

Gallery: 鈥�The robots in Google鈥檚 race to the moon鈥�

When this article was first posted, it incorrectly stated that Raytheon was still a partner of Astrobotic.