What are the RAD Rockets?
The Rocket Assisted Descent (RAD) motors are essential for a safe landing on Mars. The parachute only reduces the speed of the lander from about 400 m/s (1000 mph) down to about 85 m/s (nearly 200 mph). Thus, without the RAD rocket motors, the Mars Exploration Rover would hit the ground roughly as fast as an Indy 500 racecar. While the airbags are quite strong, there is no way that they could protect something with the mass of a small automobile moving at that speed. The brief firing of the solid rocket motors at an altitude of 80-100 meters (262-328 ft) essentially brings the downward movement of the lander to a halt some 10-15 meters or 33-40 feet above the surface. Engineers working on the RAD rockets benefitted from Pathfinder RAD designs, but had to invent a special way to prevent the backshell from tilting given winds and wind shear that are possible during entry, descent, and landing. Learn more about these RAD innovations in the technology section. Where are the RAD Rockets and
