After six Stillwater Area High School students designed and built a human-powered rover, they had to make sure it could handle the terrain found on rocky bodies in the solar system.
Where do you find a challenging exoplanetary-like landscape in Minnesota? One that mimics Mars? Or the moon?
Try the Lake Elmo Park Reserve.
That’s where the students went early one Saturday morning last month to test their creation for NASA’s 27th annual Human Exploration Rover Challenge. The winners were announced during a virtual awards ceremony April 16, and the team from Stillwater placed second in the high school division.
“We had a lot of people stop by and ask us what it was,” Vincent Ramirez, a junior, said of the early-morning test drive.
“They either gave us a weird look or walked over and said, ‘What the heck is this?’” said Jocelyn McBride, a sophomore from West Lakeland Township.
It turns out Lake Elmo Park Reserve has most of the terrain one needs to test a two-person, four-wheeled rover on a simulated field of asteroid debris that NASA specified should have “boulders from 5 to 15 inches across; an ancient stream bed with pebbles approximately 6 inches deep, and erosion ruts and crevasses of varying widths and depths.”
“We were looking for undulating terrain, hills and rocks, sand and pea gravel and stuff like that,” said Vincent, a competitive mountain biker who lives in Afton. “We just looked around for different places that had those different aspects. Some happened to be in Lake Elmo, and some were in my yard.”
Teams were required to think like NASA mission planners, developing strategies for efficiency and speed, to score the maximum number of points within the eight-minute time limit.
Why eight minutes?
That was representative of a “virtual oxygen supply,” according to NASA, and it showed “the importance of planning a mission to accomplish as many objectives as possible while balancing available time and resources.”
Among the “mission” tasks the students had to accomplish while driving and navigating the rover: a core-sample retrieval, a solid-soil sample retrieval, and “spectrographic analysis,” which involved taking photos using various colored filters.
RULES OF THE GAME
The Human Exploration Rover Challenge is usually held at the U.S. Space & Rocket Center near NASA’s Marshall Space Flight Center in Huntsville, Ala. Because of COVID, the competition was held virtually this year.
Eighty-six teams — representing 22 U.S. states, the District of Columbia, Puerto Rico and seven other countries — competed in the event. In addition to placing second in the high school division, the Stillwater team won the challenge’s Ingenuity Award.
The competition required two students, one female and one male, to traverse a challenging half-mile course. The students had to show that the rover had a turning radius of 15 feet and could go up 5-foot-tall hills and a 30-degree incline. The rover also had to be able to be disassembled so that it would be small enough to “fit into a lander equipment bay, a maximum 5 feet long by 5 feet tall by 5 feet in volume,” according to NASA.
The team, which also included Ben Abbott, Addie Foote, James Daum and Ethan Foote, spent more than eight months on the project, which started as a way to keep the students engaged during distance learning.
Tina Walski said she and her son, Vincent, started looking last summer at different learning opportunities for him. “He’s an avid biker who also loves the sciences and building, and this kind of fit all of those areas,” she said.
This is the first year a team from Stillwater has competed in the challenge; the six team members knew each other from participating in the Stillwater Area School District’s DaVinci Fest and other STEM activities.
“The last couple of months … it was literally every single evening and all day on weekends,” said Walski, who served as the team’s parent mentor. “They learned an immense amount about so many things.”
Among the laundry list of skills learned:
- budgeting
- materials sourcing
- technical writing and presentations
- computer-aided design
- prototyping
- testing
- materials research
- cutting
- welding
- taping
- carbon fiber
- molds
- assembly and reworking
WORKING WHEELS
Freshman James Daum said the biggest challenge the team faced was designing and fabricating the rover’s four wheels. Guidelines specified they could not be purchased and could not contain or operate by air or gas.
“We wanted something light,” Jocelyn said. “We ended up using carbon fiber because it’s known to be strong and light — that was actually pretty fun to figure out.”
Ben Abbott, the senior on the team, said the wheels ended up being about 4 inches wide. Urethane rubber was used to make the wheel’s tread. “We poured it into a mold and mixed it together, and then they set up and dried, and we glued them onto the rim of the carbon fiber.”
While testing the rover, team members had to wear seatbelts, bike helmets, safety goggles, pants, long-sleeved shirts “and have our shoelaces tucked in or taped down,” James said.
The rover never tipped over while team members were testing it, “but it did break a few times,” he said.
“We had a little pin that broke several times, so we went through several iterations before we found something that worked,” said Ben, who hopes to one day work “for Boeing or SpaceX or some other private space-flight company or even NASA.”
LESSONS LEARNED
The team raised about $13,000 for the project; most teams raise between $20,000 and $24,000, Ben said.
“Because we were a rookie team, we had a lot of challenges in the beginning getting access to money, which prevented us from getting access to parts and materials,” said Ben, who will be attending the College of Science and Engineering at the University of Minnesota this fall.
A key lesson learned: “There are a lot of interconnected parts, so when you change one thing, you have to go back over and make sure that everything checked out,” Ben said. “You have to verify everything. That’s really something important when you are sending something to a manufacturer, and that’s something that we messed up a couple of times.”
The team found parts online, at local bike shops and at hardware stores, Vincent said.
Vincent, who had previously designed and built a two-person bike, said his mountain-biking skills came in handy when it came to handling the rover. “We knew what to implement into our design,” he said.
There was much celebration when the team realized their rover was Mars-ready, said Addie Foote.
“We thought we had it completely finished about five times, and we kept having to go back and make little changes,” she said. “It was super-cool when we actually got it working, and we were able to drive this thing that we had been working on for months.”
