Mars rover

MAUNA KEA — The path to the moon runs through the crater of an ancient cinder cone on Hawaii’s tallest mountain.

For the past week, engineers and scientists from the National Aeronautics and Space Administration and the Canadian Space Agency have been conducting field tests with a prototype of a rover that they hope by the end of this decade will search for frozen water near the moon’s south pole.

It’s an ambitious mission, and one with tremendous stakes for the long-term future of human exploration of the solar system.

Here’s the problem: A moon colony requires a lot of water, and during the space shuttle era, the cost to boost a pound of water into low Earth orbit costs $10,000. The alternative is to mine the resources directly from the moon, or Mars, or an asteroid, in what NASA calls in-situ (on-site) resource utilization.

Before you can use the water from these other planetary bodies, you must extract it from the ground. Before you can extract it, you must find where it exists. And before you can find the water, you need RESOLVE.

That’s the name of the NASA science mission that for six days this month has been crawling around on the floor of Puu Haiwahine cinder cone on the southern flank of Mauna Kea, at about the 9,200-foot elevation. It stands for the Regolith and Environment Science and Oxygen and Lunar Volatile Extraction. CSA has donated the rover and dubbed it Artemis Jr.

The Hawaii-based Pacific International Space Center for Exploration Systems is another major partner with NASA and the CSA. NASA has not made a decision on funding the mission, which could cost up to $250 million.

Thursday, the final day of the science mission, members of the media, including the Tribune-Herald and a local film crew shooting for a Discovery Channel documentary, were invited to the test site.

Now that the tests have concluded, the public is invited to see the rover close-up Saturday at the Imiloa Astronomy Center in Hilo from 9 a.m. to 2 p.m. and to meet some of the officials who have been working on the project.

“RESOLVE is intended to go to the poles of the moon and look for the volatiles that we know are there,” said program manager Bill Larson.

These tests are intended to prove the feasibility of a remotely operated lunar prospector. Larson hopes to have a space-certified version of the rover on the moon by the end of the decade, possibly around 2017.

The tests involved almost everything that could be done in a real-world simulation without the vacuum of space. Solar panels powered the rover as it slowly rolled over the terrain. Mauna Kea was chosen because its volcanic ash resembles the fine-grained loose rock, or regolith, that comprises the surface of the moon. In an upstairs room of Hale Pohaku, a former library that was converted to a temporary mission control, a couple dozen engineers pored over computer screens, steering the rover, monitoring its progress and the science returns.

Other mission control centers were set up at Johnson Space Center, Kennedy Space Center, Ames Research Center and in Canada, watching it unfold through cameras mounted in the rover and in a mock lander. Team members have been working 16-hour days, trying to get as many goals done as they can.

Once the rover lands on the moon, the teams will have to make every second count: Because of the high latitude of the landing site, the rover will have just five to seven days to complete its mission before the moon’s rotation plunges the solar panels into darkness and temperatures of minus-200 degrees F. About 19 days later, after the sun peeks over the horizon, scientists will be surprised if anything is still working. But the polar regions are the only places where frozen water is believed to exist below the surface, as leftovers of asteroids or comets that have impacted the moon billions of years ago.

NASA and CSA have been to Mauna Kea before. In 2010, a large group of people from both space agencies ran tests using a solar collector to melt a small amount of soil and extract oxygen and hydrogen from the water. Another test demonstrated the use of a remotely operated vehicle.

This time, the science package, power and propulsion systems have been shrunk to fit on Artemis Jr. The whole package is as tall as a human and weighs about 660 pounds, or three times heavier than the equipment that would be used on an actual mission.

As it scans the surface, RESOLVE uses a neutron spectrometer and a near-infrared spectrometer to detect hydrogen, which would indicate the presence of water. It then deploys a 1-meter drill to take samples from beneath the surface, where ice is believed to exist. Samples were placed in an oven and heated to 300 F to drive out any water, methane or other gases. (The actual mission would heat lunar surface samples to 1,650 F).

An onboard mass spectrometer/gas chromatograph then analyzes the volatile gases to study their molecular composition. Buried sheets of polyethylene were used to simulate the high hydrogen content of ice.

Besides the usefulness of water for everyday astronaut needs, it also can be used as a shield to protect astronauts from harmful radiation, or it can be split into hydrogen and oxygen and used to make breathable air or rocket fuel.

The next step for the team will be to design a rover that can withstand the harsh conditions of outer space.