Canadian and American scientists plan to put an unmanned aircraft through a series of test maneuvers over an Arctic impact crater in hopes of learning more about how to fly missions through Martian skies. “A Mars airplane project will look very different from this one,” said Emily Lakdawalla, project coordinator with the Planetary Society, of Pasadena, Calif., which is sponsoring the test flights along with NASA’s Ames Research Center and aircraft manufacturer MicroPilot, a division of Loewen Aviation of Canada. “However, both projects involve making choices about observational targets that are interesting from a scientific standpoint and safe from an engineering standpoint — a choice that must be made with every remote sensing mission,” Lakdawalla said in an interview with United Press International.