To the Moon and Mars--Efficiently
Managing supplies for manned space missions.
A man in a space suit makes his way across the barren reddish terrain, testing the suit’s information display systems. A cluster of tents and an automated greenhouse are the only other signs of life. Suddenly an all-terrain vehicle growls in the distance. This is Devon Island in the Canadian Arctic, the place on Earth that is most like Mars. Every summer, when the weather is relatively mild, researchers come to the international Haughton-Mars Project (HMP) base to create and test equipment for future manned missions to the fourth planet.
Last summer, a team of MIT researchers used the base for the first time. Led by Olivier de Weck, assistant professor of aeronautics and astronautics and engineering systems, and civil- and environmental-engineering and engineering systems professor David Simchi-Levi, the group has a $3.8 million, two-year grant from NASA to research efficient ways to supply future manned missions to the Moon and Mars.
The first phase of the MIT project dealt with onboard inventory, which can suck up astronauts’ valuable time. According to de Weck, astronauts on the International Space Station spend several hours a day keeping track of items, such as food and scientific equipment. “What they’re really supposed to be doing is productive science,” he says.
Today, space station astronauts keep track of their supplies by giving each item two bar codes that must be manually scanned – one that identifies the item and another that specifies its location. “One of the hypotheses we’re trying to test…is whether a more hands-free operation would be beneficial,” says de Weck.
On Devon Island, the group tested this hypothesis by taking an inventory of every item on the HMP base – from dried fruit to all-terrain vehicles – and giving each a radio frequency identification (RFID) tag. Unlike bar codes, which must be scanned by hand, RFID tags use radio signals to communicate with nearby readers, which may be handheld or mounted on, for example, ceilings, walls, gates, or vehicles.
De Weck and Simchi-Levi’s group used RFID readers mounted on gates to track the base’s all-terrain vehicles and improve scheduling procedures. On the Moon or Mars, a portable RFID reader could be used to determine which supplies are in an exploration vehicle before astronauts take it for a day trip. The reader could “go through the Humvee, find out what’s in the truck, compare it with a standard equipment list, and give a green or red light to the mission,” says Mike Li, the project’s software architect.
Though the MIT researchers are still analyzing the data, they believe that RFID tags are more efficient than bar codes but less precise. For instance, they have found that sometimes the RFID reader doesn’t pick up a signal. To overcome this, spaceships may need multiple readers that can pick up RFID signals coming from many different angles.
Simchi-Levi says the researchers are working to determine how many readers might be needed in a space shuttle. “Clearly, it will not be a low number,” he says. The answer to this question will influence NASA’s designs for future space vehicles. “We need to make NASA and their suppliers aware of this now…so that in five or ten years, [RFID] will be a useful technology,” says de Weck.
The group is now studying the most efficient ways to supply manned space missions, since future space supply chains will likely be very different from those of the Apollo Program, whose manned missions ran from 1969 to 1972. Apollo astronauts went to the Moon with everything they needed and came back with almost nothing.
In the future, NASA may establish “warehouses” of supplies in space, whether on the Moon, on Mars, or at the stable gravitational point about 85 percent of the way to the Moon. The MIT team is researching whether or not this strategy is worth pursuing. RFID technology could also be used to assess the quality of supplies stored in warehouses in such harsh environments, where extreme and rapid temperature changes are common.