A View from Brittany Sauser
New Heat Shield for Mars Rover
The thermal protection system for Curiosity is bigger and better than anything before it.
NASA’s next Mars rover’s massive heat shield is finally ready for the robot. It is the largest heat shield ever built for a spacecraft destined for the red planet–not surprising since the rover is about the size of a small car and could endure temperatures up to 3,800 degrees Fahrenheit when it enters the Martian atmosphere.
The heat shield is made from a novel material first used on Stardust, a comet-sample-return mission launched in 1999. The material’s properties make it ideal for high-peak-heating conditions such as those the rover, recently named Curiosity, will experience as it journeys to Mars.
Without an adequate thermal protection system or heat shield, the rover could burn up. This was proved tragically in 2003, when the space shuttle Columbia’s heat-resistant shield was damaged during launch. The damage went undetected, and the shuttle, left with a comprised system, lost structural integrity and broke apart during reentry to the Earth’s atmosphere.
However, the shuttle’s thermal protection system is a combination of reinforced carbon-carbon on the wing leading edge, thermal blankets on the fuselage, and thermal protective tiles covering the underside of the vehicle and the nose cap. It is meant to shield against heat loads since the shuttle undergoes multiple reentries. Curiosity’s heat shield is a large aero shell that covers the rover and is made of a material called phenolic impregnated carbon ablator, developed at NASA Ames Research Center. The material is low density so it can withstand searing temperatures, making it ideal for lunar and Mars missions.
The heat shield was manufactured by Lockheed Martin and is the largest ever built for flight–it’s 4.5 meters wide including the back shell, larger than the heat shields for the Apollo spacecraft (under 4 meters) and for the current Mars rovers, Spirit and Opportunity (2.6 meters). Uniquely, once Curiosity enters the Martian atmosphere, parachutes will deploy to slow its descent, and it will jettison its heat shield, using thrusters and a crane to reach the surface of Mars. (Watch a video of how the rover will land.)