Nanorover bound for asteroid
June 28, 1999
By Robin Lloyd
(CNN) - NASA's next rover can leap small buildings in a single bound but weighs just a little more than Superman's cape.
Unlike its Mars-touring cousin Sojourner, the latest rover, called a nanorover because it is so small, is being designed to hop around an asteroid measuring a kilometer, or about a half-mile, in diameter. The red planet is about 6,774 kilometers, or 4,200 miles across.
Engineers at NASA's Jet Propulsion Laboratory are refining the advanced rover in preparation for a mission called MUSES, overseen by the Japanese space agency and set for launch in January 2002. The trick is learning how to drive on an asteroid.
"You've got the same problem as a car on Earth on a sheet of ice," said Don Yeomans, NASA's project scientist for the mission. "There is very little friction between the wheels and the surface."
"So you can creep along at 1 millimeter per second or you can take these enormous leaps, and that's the preferred mode of operation," he said.
A more sophisticated rover
The MUSES rover, about the size of a fat paperback novel, hops by squeezing its struts together like scissors. The asteroid's small gravitational field would allow it to hop up to tens of meters, or yards, high and land in a new spot, Yeomans said.
If the rover lands on its back, it is designed to right itself. "The trick is to not be too enthusiastic, to start off with a little jump," he said. "We don't want to put this thing in orbit."
The MUSES rover is 10 times smaller than the Mars Pathfinder mission's Sojourner, has a more sophisticated on-board computer and has a color camera, not black and white, Yeomans said.
And where Sojourner had to settle for detecting the basic elements found in surface rocks, the MUSES rover will have an infrared spectrometer that can detect more complex minerals at the asteroid's surface.
The MUSES rover also will have a grid of wires on its solar panels that can be charged up to reject dust and keep it from mucking up the machinery.
Asteroids to get lots of traffic
Many people became more aware of asteroids in 1998 with a false alarm for an asteroid-Earth collision and the release of asteroid movies "Deep Impact" and "Armageddon."
NASA is sponsoring other missions involving asteroids, including Deep Space 1 which is set to pass by asteroid 1992KD next month and the Near Earth Asteroid Rendezvous mission which is set to enter the orbit of the asteroid Eros on Valentine's Day, 2000. The European Space Agency also plans to send up a spacecraft to land on a comet and fly-by two asteroids.
Yeomans says MUSES is uniquely challenging.
"We hope to bring back surface samples for study in Earth-based laboratories," he said. "And we intend to drop the little nanorover on the surface and have it run around and make TV images and detect what the thing is made of in terms of minerals and the elemental components of the rocks -- iron, calcium, magnesium and oxygen in a particular rock."
MUSES is set to visit an asteroid called Nereus which orbits near Earth. At the time of the craft's arrival to the object, it will be about 245 million miles from Earth.
Up to three asteroid samples will be collected by the lander. After a two-month stay on the asteroid, the plan is for a capsule with the samples to separate from the lander and eventually parachute to Earth's surface in 2006.
The NASA portion of the mission costs about $30 million. A team of six U.S. scientists was named this week to work on the rover part of the mission, including Peter Smith of the University of Arizona, who oversaw the camera on Sojourner.
Space Day 1999: Glenn announces school children will help drive next Mars rover
JPL Picture Archive: MUSES-CN - Spacecraft
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