MAUNA KEA, Hawai'i — Nine thousand feet above sea level, but a quarter-million miles short of where they want to be, space scientists and engineers have built a proving ground for future moon missions.

Located alongside an old cinder cone, on the south side of the mountain, the field tests are a collaborative effort with NASA, the Canadian Space Agency, the German Aerospace Center and the University of Hawai'i-Hilo's own Pacific International Space Center for Exploration Systems.

Many of the studies are technical, and the detailed explanations of what each meant left visiting news people scratching their heads Thursday, trying to make sense of it.

But the intent of scientists' work was clear — helping humans return to the moon.

"This is the PISCES test site," said director Frank Schowengerdt, "where we invite people from all over the world to enable people to live on the moon and off the Earth."

As it happens, Hawai'i is about as far as anybody can get from the conditions on the moon, where deadly radiation and micrometeoroids bombard the airless surface, where temperatures swing hundreds of degrees between sunlight and shade, and where no human has gone in nearly 40 years.

In another sense, however, Mauna Kea and the moon share something in common: The fine-grained soil at the base of the cinder cone is chemically similar to lunar regolith, the stuff that comprises the moon's surface.

This makes it an ideal place to test technology that can extract hydrogen and oxygen from the moon's surface. From those two elements, engineers are creating water, electricity, breathable air and rocket fuel. All these things are too expensive to bring to the moon for a long-term stay, so future astronauts will have to make them there.

That's assuming, of course, that astronauts ever get there. The Obama administration has proposed ditching NASA's $100 billion plan to return humans to the moon and using much of that money for new rocket technology research. NASA is spending $300,000 on the Mauna Kea site, and the Canadians have sunk $4 million into building the rovers and other technology.

Despite Obama's bombshell, about 100 people commute to the site daily, taking a steep, unpaved road to the cluster of about two dozen dusty tents. Scientists milled around in the thin atmosphere, keeping to a tight schedule during the 2 1/4 weeks they are here. When they leave next week, the site will be returned to its original condition, minus the trash and invasive California grass.

One of the devices being tested concentrates heat from the sun to melt a small amount of soil, fusing it into a solid surface so it may be used as a launch pad. The same solar collector is also used to heat soil into lava and, with the addition of two other elements, start a chemical reaction to extract oxygen and hydrogen.

By the end of the week, researchers will have enough hydrogen and oxygen to ignite a small rocket thruster and see the effects on the launch pad they've created.

They like to call the whole process "Dust to Thrust."

Other rovers, using laser sensors, were operating autonomously, gathering the regolith or surveying the faux lunar surface.

This is the second time PISCES has invited the scientists to come to Mauna Kea. They were also here last year but have not made a decision on returning in 2011.

Someday, Schowengerdt said, the center will have a permanent lunar test site on Mauna Kea.