Monday, May 15, 2000 A Publication of The Ohio State University School of Journalism	Current Issue: 05/15/00
Mars rover has OSU connection
Hsiu-wei Hsieh Lantern staff writer
Ohio State researchers will be helping the National Aeronautics and Space Administration to investigate the surface of Mars in the future missions.With support from Jet Propulsion Laboratory in California and OSU's Department of Civil and Environmental Engineering and Geodetic Science, NASA's Mars Surveyor 2001 Orbiter is scheduled for launch next year and will include a lander and a rover.Starting as a subcontractor with NASA since 1998, Rongxing Li, an associate professor of civil and environmental engineering, has been trying to improve the accuracy of the Mars rover localization with a development of a mapping system, which will be used on NASA's Mars missions planned for 2001, 2003 and 2005."We developed a software system here at Ohio State and JPL converts our software to the system they have on board of the rover for the real-time processing," Li said.According to Li, NASA wants to have a more powerful rover that would go up to one kilometer or more further from the lander, take samples from the surface and gather other geological features from Mars in the upcoming mission."The problem is you need to know where the rover is and what its distance from the lander is. If a rover takes a sample from a certain position, goes back to the lander and deposits the sample, then it has to go back to the same point," Li said. "You need to know exactly where the rover is right now, where it was before and where it wants to go. This is a problem of navigation."All of NASA's investigations will depend on the lander and the rover in Mars Surveyor 2001 mission. The rover relies on solar energy, Li said."Such a huge mission has too many components. The problem we worry about in the future mission is that if the rover is turned upside down or it slips, then the rover won’t ever work anymore since its power depends on the solar panel on the top," he said.Li said his team wants to get decent images in future missions which will be taken by a camera mounted on the rover."During the descent, the rover will create a terrain map database of the landing site, and the camera on the rover will take pictures all the time," Li said.  "We can use these pictures to build a map of the area, so the rover will be able to see where to go, and the rover itself will take pictures as well, while going around."Li and JPL finished two simulation tests in April 1999 and in April 2000 in California's Mojave Desert. They used a helicopter to simulate the lander operation and a rover to take pictures when it moved along the landing center."We had decent pictures and rover pictures in those experiments and used the software system to calculate the rover position," Li said.  "The simulation results we have proven will satisfy NASA's requirement by using our methods."