It's more than 10 times faster than the Space Shuttle's on-orbit speed of 5 miles per second. Johnson says transportation is quite possibly the toughest challenge with interstellar missions because they have to go so far, so fast. The difficulty is that rockets need so much fuel that they can't push their own weight into interstellar space. Rays of light from the Sun would provide tremendous momentum to the gigantic structure. Nothing this big has ever been deployed in space.
Researchers are optimistic about recent breakthroughs with strong, lightweight composite materials.
In space the material would unfurl like a fan when it's deployed from an expendable rocket. The Marshall Center is leading NASA's transportation research for interstellar probes. Engineers at Marshall are conducting laboratory experiments to evaluate and characterize materials for space sails. Materials will be exposed to harsh conditions in a simulated space environment to test their performance and durability in extremely hot and cold temperatures. The emphasis of the current research effort is on the interstellar precursor missions designed to set the stage for missions to other star systems later this century.