When humans land on Mars, they'll need something to drink.
And after a two-year trip to get there, a shower probably wouldn't hurt.
A team of University of Tennessee engineering students may have a hand in providing the water astronauts use on the Red Planet. They are one of 10 finalists in NASA's Mars Ice Challenge, a college competition to design and build a machine to extract liquid water from Mars' subsurface ice.
"We were notified probably about three weeks ago that we were selected as finalists," said Skylar Jordan, a junior aerospace engineering major from Seymour. "Couple of weeks after that we got our first stipend."
Jordan is part of the three-member executive team, a primary paper writer, and approves part ordering, he said.
Each year NASA and the National Institute of Aerospace sponsor RASC-AL, which stands for Revolutionary Aerospace Systems Concepts – Academic Linkage. It's a design competition for college engineering students. The RASC-AL Special Edition: Mars Ice Challenge, also held last year, asks students to design, build and demonstrate machines to extract water from underground Martian ice.
Teams from 10 schools will go to NASA's Langley Research Center in Hampton, Virginia, on June 6 for a final competition. UT'S "This Is Not A Drill" team is the only finalist from Tennessee.
Last semester the team worked on its written proposal, due around the start of December, Jordan said. Now the members have until June to build a functional machine.
For the team to build and test it, NASA provides $10,000 in two installments, but the team can accept other funding, said Gabriel Hatcher. Hatcher, a sophomore aerospace engineering major from Seymour, said UT's team is nearly unique in being made up mostly of undergraduates.
A team from UT was a finalist last year, and many of its members returned for another try this time.
One is Emily Beckman, a senior aerospace engineering major from Murfreesboro. She joined last year when team leaders, some of her friends, were seeking enough interested students to compete, she said. Now Beckman works on the chassis sub-team, designing the machine's framework, and sometimes works with others on moving parts.
In addition to the prestige of the competition, it's valuable as real-world engineering practice, she said. Students get a little of that as freshmen, and some in senior design courses, but don't usually have much chance to make a design wholly on their own, Beckman said.
"Hands-on experience is the main thing," she said.
Team, building
The team's adviser is James Coder, assistant professor of aerospace engineering, but he said the project is really student-led and student-run.
"I think this team is doing a tremendous job," Coder said. "I'm very proud of the effort they've put into it, and I'm looking forward to how well they'll compete in June."
Most of the team members are sophomores and juniors, Jordan said. A couple are freshmen, there are a few seniors, and one graduate student, he said. Most of the members are aerospace engineering majors, and most are from Tennessee.
"We do have a few members from the electrical engineering department," Jordan said. "They are extremely essential."
Altogether there are 36 students involved, though due to classes and other commitments they aren't usually all at every meeting, Jordan said.
Four sub-teams, each working on a different aspect of the project, meet individually, but the whole team meets every Tuesday and Thursday evening in a cluttered, concrete-walled room on a lower level of the Dougherty Engineering Building.
At Tuesday night's meeting the crowd in the room varied - 20, 15, 18 - as people came and went.
Students in assorted old chairs huddled over laptops, while a few others built part of the device for testing on a table strewn with wires. Nearby, next to carefully organized shelves of tools and parts, stood a plywood crate holding a freezer - the frame for mounting and testing the whole machine.
Hatcher was part of last year's project and spent about a month working on it "day in and day out" as other team members had to leave campus for jobs and internships, he said. A few of last year's team members graduated, but Hatcher was among the many who returned. Now he's one of the project leaders, helping coordinate sub-teams, doing some computer-aided design and lots of the hands-on assembly, he said.
Some parts can be bought off the shelf, but many are made right in the engineering building, 3-D printed or water-jet cut, Hatcher said.
Goals and methods
It's NASA's goal to send people to Mars in the 2030s, several at a time. To prepare for that the space agency is sending multiple robot probes. The Mars 2020 Rover, the next one scheduled, will have a drill to test soil and instruments to spot subsurface water, but not to create liquid water specifically. "Follow the water" is a guiding principle of Mars exploration, essential in preparing for a human visit, so future landers are sure to test the feasibility of digging for frozen water.
"Due to strong hydrogen signatures, Mars appears to be rich in water frozen under the Martian surface, making the Red Planet a viable destination for us," Melvin Ferebee, director of the Systems Analysis and Concepts Division at NASA Langley, said in a news release. "Water is there, but it is buried. It is absolutely crucial that we figure out a way to effectively and efficiently access that water. And the Mars Ice Challenge provides us with a variety of potential options to start solving that problem."
In 2017 almost every team relied on drills and narrow pipes, Hatcher said. This year UT's team is starting with a digger that removes dirt from a wider area, then drills into the ice, he said.
Experience is helping a lot in designing this year's machine, Jordan said.
"Last year we had a problem with our digging device, but our ice melter was excellent," he said. The test bed used in 2017 was muddier than Mars is believed to be, which gunked up the digger, Jordan said; this year's test bed is supposed to be drier, but the team isn't taking chances - a different kind of digger is on this year's plan. Both the ice melter and the digger are better on the new machine, but the digger is greatly improved, he said.
The rotating scoops used last year have been replaced with an augur, Beckman said.
"We've done a little bit of testing so far, and it seems to work really well," she said.
The finished device has to fit in a 1-meter-by-1-meter-by-2-meter space, can't weigh more than 60 kilograms, and is limited to 1,200 watts of power, Hatcher said.
It has to dig through a half-meter of dirt to reach a half-meter chunk of ice, liquefy and filter it, and draw it into a storage container. The process is complicated by Mars' surface conditions: Water changes directly from a solid to a gas at the planet's normal temperature and atmospheric pressure, Jordan said.
There are awards for the lightest machine, the one that produces the cleanest water, and a few other achievements, he said, but the overall winner is determined by who extracts the most liquid water.
"One of the things we found out last year was that water pumps do not like debris," Hatcher said. "They tend to explode."
After researching many types of pumps, the team settled this time on a peristaltic pump, which can handle thick or abrasive liquids.
Jordan said the next milestone is a mid-project review at the end of March, when the team will submit a finished plan.
"That is when we want to have a working prototype," he said.