July 20, 2009 was a monumental day for the University of Maine’s Electrical & Computer Engineering Department. First, it was the 40th anniversary of the first moon landing. And, appropriately enough, it was the day that two tractor trailers from NASA rolled unexpectedly onto campus while bearing an exciting cargo that has become a draw for school groups of students fascinated with engineering and outer space.
Dr. Ali Abedi, research director at the ECE’s Wireless Sensor Network Lab, had lobbied NASA hard to get that cargo. He recalled scrambling to find somewhere to store it until a new building could be erected. Now, UMaine is the proud steward of a one-of-a-kind inflatable lunar habitat, the first stage of a design that will ultimately house humans on the Moon, Mars, or elsewhere.
“It’s a prototype,” said Abedi. “It’s just an idea to kind of keep us thinking of what needs to be done.”
UMaine’s part of the project is to design and test a revolutionary sensor array designed to monitor the habitat’s shell for inflation pressure, external impacts, and air leaks. The last one is key, as micrometeorite punctures might go unnoticed by humans.
Lunar habitat. Sensor array. It all sounds like science fiction, but it’s reality. The project began years ago when Abedi worked with NASA to develop a wireless, battery-less sensor; he later won a grant for the development program, which ultimately brought the habitat to UMaine.
The final lunar habitat will have thermal, radiation, and microimpact protective layers, but for now, the team only needs this inflatable prototype. Inside are 124 sensors, adhered to the outermost wall; powered by electromagnetic radiation in the air, they run without batteries and detect air leaks by monitoring ultrasonic waves. The team members test for simulated leaks by using ultrasound, enabling them to test any number of possible leak scenarios without poking holes all through the habitat. The sensors broadcast radio-frequency data, just like RFID tags used to track retail merchandise.
The off-the-shelf sensors cost pennies, but are useless without the right software to interpret their data. That’s what Abedi and his students have been doing. Special equipment running their software polls the tiny bits of data from the sensor array, interprets it into usable information, and even creates a three-dimensional representation of the habitat.
To those who feel money spent on space research is wasteful, Abedi disagrees. “All these technologies we develop for space often can be employed here in Maine: agriculture, businesses, bridge monitoring, or for emergency management,” he said.
The sensors could detect tremors in a bridge or swaying in a building. At the Jackson Lab, they check humidity changes in cages to detect mouse births. In UMaine’s ECE department, the sensors are monitoring classroom and lab temperatures to build a data model of power usage. Similar sensors were used to monitor H1N1 flu vaccines during shipment to ensure consistent temperature, which is key to their viability.
Abedi said that the project is very exciting for the students and gives them invaluable experience that looks great on resumes. Last year, he and several students visited the Mojave Desert to participate in a rocket launch. On board was a UMaine-designed wireless-powered sensor for some real-world testing; it outperformed the battery-operated sensors without signal interruption and up to a mile away instead of just 300 feet.
“It was a pretty cool experience, and to be a part of that was great,” said Joel Castro, one of the students at the launch.
This summer, Castro and grad student Frederick Schwaner will intern at NASA while working on wireless-sensor research from May through July. Castro says it won’t feel much like work.
“It’ll be a … cool experience that not a lot of people get to say they do,” he said.
Castro hadn’t planned to do graduate studies, but the arrival of the lunar habitat changed that. Like many people, as a child he’d wanted to be an astronaut; in high school, he considered aerospace and aeronautical engineering. He settled on electrical and computer engineering at UMaine, but found himself working on a NASA project. “Long way around, I got back to NASA anyway,” he said.
The lunar habitat is frequently open for school-group tours, and Abedi said he’s happy to work with educators who request tours.
“We bring lots of middle-school and high-school kids also to just walk inside, touch the sensors, and take pictures, and kind of excite them in science and technology,” he said. “You can’t imagine how excited they are… they just can’t stop talking.”
Abedi said he’s hoping to secure funding for some sort of summer program — perhaps a camp where kids can learn about the habitat, sleep in it for a night, and do some experiments in the morning.
Teachers interested in tours for their science students should contact Abedi at firstname.lastname@example.org to learn more.