The robot aircraft, named Kitty Hawk after the town in North Carolina where Orville and Wilbur Wright made their famous flight in 1903, will spend three hours soaring over the spectacular gorges of the Valles Marineris, a canyon system as wide as North America and more than 25,000ft (7,600m) deep in places.
Daniel Goldin, Nasa's administrator, wants to launch the mission before the end of 2002 in order to rendezvous with Mars in time for the centenary of the Wright brothers' flight on 17 December 2003.
Space scientists believe a lightweight plane fitted with a propeller at the back and powered by a small engine could cover more than 1,000 miles in the course of three hours, taking unprecedented images of the deep canyons of Mars.
The aircraft will be bristling with instruments to measure gravity and magnetic fields as well as stereo cameras to provide high resolution images of the terrain below. One of its aims will be to search for a possible landing site for a mission to collect samples of Martian rock and bring them to Earth.
"One of the key aspects of Mars exploration involves the search for the best places from which to return samples, places where geology indicates the possible past presence of water or layered sediments," said Dr Michael Malin, one of the private consultants on the mission who has been working closely with scientists at Nasa's Ames Research Center in California. "Another involves the reconnaissance of features that are very large and widely separated, features hundreds to thousands of miles across," Dr Malin said.
"In both these cases, the resolutions needed are not attainable from orbit and covering thousands of miles of extremely rough terrain is not possible with surface rovers."
Kitty Hawk will weigh about 300lb (135kg) and its 32ft (10m) wingspan will unfold after being ejected from its mother spacecraft at an altitude of about 6,500ft (2,000m). Nasa will spend about about $9m on Kitty Hawk, making it a relatively low-cost project.
Scientists hope the data will help them to understand the geological forces, such as sedimentary deposition and erosion, that helped to shape our nearest planetary neighbour. They also hope Kitty Hawk will provide the reconnaissance needed to help them search for the most likely place to find rock samples that could contain evidence of Martian life.
Kitty Hawk will send data back to an orbiting spacecraft which will then relay the images and information back to mission control on Earth.