Defying 30 mph
gusts1 and temperatures down to minus 22 F, NASA's new polar rover recently demonstrated in Greenland that it could operate completely
autonomously3(独立自主地) in one of Earth's harshest environments. The robot known as GROVER, which stands for both Greenland Rover and Goddard Remotely Operated Vehicle for Exploration and Research, was designed by teams of students attending engineering boot camps at Goddard in the summers of 2010 and 2011. Built to carry a ground-penetrating
radar4 to
analyze5 layers of snow and ice, the rover was later transferred to Boise State University for fine-tuning with NASA funding.
Although researchers had tested GROVER at a beach in Maryland and in the snow in Idaho, the May 6 to June 8 testing at Summit Camp, the highest spot in Greenland, was the rover's first polar experience. One of the main goals was proving that the robot could execute commands sent from afar over an Iridium satellite connection -- an objective GROVER
accomplished6.
"When we saw it moving and travelling to the locations our professor had keyed in from Boise, we knew all of our hard work had paid off," said Gabriel Trisca, a graduate student from Boise State University who has been involved in the GROVER project from its start. "GROVER has grown to be a fully-
autonomous2, GPS-guided and satellite-linked platform for scientific research." Trisca accompanied the robot to Greenland.
GROVER collected and stored radar data over 18 miles during the five weeks it spent on the ice. During the testing, the rover was also able to transmit information in real time on how its onboard systems were performing. The robot's solar-charged batteries allowed it to operate for up to 12 hours before having to recharge.
"When you work at the poles, on the ice, it's cold, it's tiring, it's expensive and there's a limit to how much ground you can cover on snowmobiles," said Lora Koenig, a glaciologist at NASA's Goddard Space Flight Center in Greenbelt, Md. "It would be great if autonomous robotic platforms could do part of this work -- especially the part where high winds and blowing snow try to freeze your skin."
Though researchers had
initially7 expected the 800-pound robot to work around the clock and cover more ground, the extreme polar conditions took a
toll8 on GROVER's electronics, battery consumption and
mobility9.
"This is very common the first time you take an instrument into an environment like Greenland," said Hans-Peter Marshall, a geoscientist at Boise State University and science
adviser10 on the project. "It's always more challenging than you thought it was going to be: Batteries don't recharge as fast and they don't last as long, and it takes computers and instrumentation longer to boot."