Water ice believed by scientists to reside at the lunar poles is the key to opening up the solar system to human activity. The water could help sustain a lunar settlement. It could also be refined into rocket fuel, not only to sustain travel to and from the moon but to make it a refueling stop for spacecraft headed deeper into the solar system. A recent MIT study suggested that lunar fuel would simplify NASA’s Journey to Mars. Thursday, lunar scientist Paul Spudis, writing in Air and Space Magazine, pondered the next step in determining the extent and composition of the lunar ice.
Spudis’ idea is to deploy several dozen impact probes across one of the lunar polar regions.
“I am interested in the amounts and distribution of water ice at the poles of the Moon, which is apparently widely distributed across the surface. But multiple soft landers would be very expensive (about $100 million or more per lander) and a long-lived, nuclear-powered surface rover (designed to roam widely and go into and out of the dark, polar cold traps) might cost upwards of $1 billion. However, cheap probes designed to crash land on the Moon can be made for only a couple million dollars each; for the cost of a single, powered lander, we could make dozens of these small probes. Each probe would be battery powered and would carry a neutron spectrometer, imager, radio, and antenna. After landing, they would make measurements and radio the results up to an orbiting companion spacecraft before their operations stopped. This approach gives us better data coverage than a single lander—points of measurement would be distributed over a wide area.”
The impact probes would be equipped with aluminum foam to cushion them as they hit the lunar surface. Then each of these probes would measure the surface hydrogen as well as the neutron signature of volatiles on the moon where they land and then transmit their findings to an orbital craft for relay to Earth. If a few of the impact probes fail, it would not affect the success of the overall mission.
Spudis states that the idea of a multiple impact probe mission is currently conceptual. However, if the next president, as many expect, places the moon back on NASA’s agenda, the mission would make a good first opening act for a campaign that would lead, in short order, to a return to the moon. Knowledge of the water ice would be vital for the setting up of a lunar settlement. The settlement would not only be a center of science and commerce on Earth’s nearest neighbor but would support NASA’s ambitious plans for exploring Mars and beyond.