Having trod a career path from Shanghai to Columbus by way of Germany, Hawaii and Canada, Ron Li now wants to navigate Mars. Not that Li has aspirations to kick up the red dust himself. Instead, as a professor of geodetic science at Ohio State University, he’s working to develop the navigational tools to guide robotic rovers across that alien world in 2003 and beyond. Li has proposed that rover maps be made from a series of camera images of the landing area snapped from the spacecraft as it descends. Another option is mapmaking from photographs taken by satellites orbiting Mars.