Tim Furniss/LONDON
Prospects for an eventual mission to one of the poles of the Moon to obtain ice samples have been boosted because data returned from the Lunar Prospector orbiter show a "high probability" that water ice exists.
NASA, however, will be unable to support a fully funded mission as the majority of its budget is committed to the International Space Station and Space Shuttle programmes, already under heavy criticism from Congress because of cost overruns and delays.
Although no NASA follow-on missions have been funded, several organisations in the USA, Europe and Japan have proposed Moon flights, which could be refocused to probe the lunar poles to confirm the findings and later to bring samples back to Earth. NASA is investigating ways to co-operate and contribute to these.
One project is the European Space Agency's Euromoon polar lander and orbiter, which could be given the go-ahead later this year. Japan is planning an orbiter landing mission, called Selene, for launch in 2003, but this is not now targeted for a polar landing.
The US Carnegie Mellon University proposed the Lunar Ice rover mission in 1997 as a candidate for NASA's Discovery programme, but failed to win approval. This could now be reconsidered.
Another project, called Lunar Retriever, has been proposed by Applied Space Resources of New York. This could become the first to bring samples back from one of the lunar poles. The mission, which could be launched as early as 2001, requires private financing by organisations interested in examining or selling samples and capitalising on further commercial possibilities, including developing ways to process the soil to extract the water.
As NASA has now agreed that instruments and experiments can be proposed for funding to fly on privately financed craft as part of the Discovery programme, the space agency could part-fund a sample-return mission, such as the Lunar Retriever, by supporting some of the payloads flying on it.
The much publicised possibility of a manned Moon base - using water for life support and as the raw material for rocket propellant, have been played down by NASA.
The space agency warns that a "cost effective method to mine the water crystals from within this huge volume of soil would have to be developed if it were to become a real resource for drinking water or as the basic components of rocket fuel to support any future human explorers".
Although the presence of water is "strongly indicated" by the Lunar Prospector's neutron spectrometer, the water ice is not concentrated in polar ice sheets, a mission scientist has cautioned.
"While the evidence of water ice is quite strong, the water signal itself is relatively weak," says Dr William Feldman, co-investigator and spectrometer specialist at the US Department of Energy's Los Alamos National Laboratory, New Mexico. NASA says that there could be up to 300 million tonnes of lunar water ice, most of it at the north pole.
Source: Flight International
