Development and Construction of a Prototype Mars Tumbleweed Rover

The Mars Tumbleweed is a prototype wind propelled sc out rover in development for the exploration of Mars. The Tumbleweed harnesses the power of the wind as the only form of propulsion, allowing the rover to traverse much larger distances more quickly than conventional rovers do. The Tumbleweed Earth Demon strator (TED) is the product of North Carolina State University’s senior design project in Aerospace Engineering. The purpose of the TED is to emulate the capabilities of the Mars Tumbleweed in Earth conditions. The senior design class of 2002 -2003 built the first Tumbleweed and the 2004 2005 class built the second iteration of the Mars Tumbleweed, appropriately named the Tumbleweed Earth Demonstrator 2 (TED2). This rover is 3 meters in diameter, while the Mars rover would be 6 meters in diameter. The l arge size of the Mars rover is necessary due to the low atmospheric density on Mars (as compared to Earth) that mandates that the sail area be large in order to generate enough drag for propulsion. The TED2 includes internal sails, full instrumentation, a nd solar panels as well as new design features, such as the double gimbal and Modular Instrument System (MIS). Rolling tests were conducted on campus and two problem areas were identified: the hubs and structural strength. Using these results, a team of five students worked during the summer of 2005 to correct problems, reconstruct the TED, and further the testing. From this research, the TED3 was born, and in total three rovers were built during the summer. The TED3 features new structural materials an d extra structural supports in the form of two side rings and a redesigned hub, but TED3 retained most of the TED2 characteristics. The three new rovers were taken to South Nags Head beach, North Carolina and Lake Toxaway in the mountains of North Carolin a to investigate the overall behavior of the rovers along with the drag and rolling dynamics. Some results of the TED2 were the confirmation that the double gimbal and MIS function properly. The TED3 tests yielded data on the high level of interference i n group situations and the impressive durability of the rover. This paper describes the detailed research and results obtained by the two teams of students.