An inflatable heat shield for spacecraft headed to Mars may, one day, help humans settle on the Red Planet. Such a device is being designed at NASA's Langley Research Center in Hampton, Virginia.
The atmosphere on Mars is much thinner than that of the Earth, and NASA engineers are studying ways to land massive payloads on the Martian surface. Rockets, like parachutes, cannot currently be used to slow large vehicles enough for a safe landing on Mars.
One idea currently under consideration involves the construction of an inflatable heat shield, resembling the stacking doughnut toy used by infants. Each segment of the shield, covered in a thermal blanket, would be inflated with nitrogen during entry into the Martian atmosphere. This revolutionary heat shield is designed to sit on top of the lander, resembling a giant mushroom.
"We try to not use propulsion if we don't have to. We make use of that atmosphere as much as we can, because it means we don't have to carry all that fuel with us," Neil Cheatwood, senior engineer at Langley for advanced entry, descent and landing systems, said.
An Antares rocket, designed by Orbital Science Corporation, exploded seconds after takeoff on October 28, 2014. A second-generation inflatable rocket was scheduled to be placed aboard that flight for testing, but delays caused the experiment to be bumped from the doomed mission. The next flight of Antares is scheduled for 2016, carrying the craft, designed to test inflatable technologies.
Astronauts traveling to Mars will journey aboard the Orion spacecraft, which recently successfully passed its first flight test. The heat shield on that vehicle is constructed of a titanium skeleton, underlying a carbon fiber skin. Inside the shield, a fiberglass-phenolic honeycomb structure, containing more than 330,000 individual cells, fill out the structure. This insulation is similar to the material used during the Apollo project, with great success.
Inflatable heat shields could be used to land spacecraft on worlds other than Mars, including Venus and Titan, as well as lower vehicles into the dense atmosphere of Jupiter.
In July 2012, NASA successfully tested an inflatable heat shield, driving the device at velocities of nearly 7,600 miles per hour.
"We are pushing the boundaries with this flight. We look forward to future test launches of even bigger inflatable aeroshells," Lesa Roe, director of NASA's Langley Research Center, said.
Engineers at NASA will need to design a wide range of new technologies to meet their announced goal of setting humans on Mars by the 2030's. Long-term living quarters will need to be constructed, as well as new propulsion systems, next-generation spacesuits, and communication equipment.