Sunjammer is set to launch in November, 2014, and if it sounds like the name of a type of sailboat, there is a good reason for that - the craft will have the largest solar sail ever deployed in space. The Sunjammer will launch from Cape Canaveral aboard a Falcon 9 rocket, built by Space X.
This vehicle will test he idea of "propellentless propulsion," or riding the solar wind in a manner similar to a sailboat riding winds over the water. The solar wind is a steady stream of charged particles emitted by the Sun which pour out from our star at one million miles per hour. The craft will ride these particles, mostly electrons and protons, using a solar sail measuring 124 feet on each side.
After separating from the lift vehicle, the Sunjammer will deploy its solar sail, one-third of an acre in size, and attempt to catch the charged particles. It's first destination lies 1.8 million miles from our home world.
"We're excited about seeing Sunjammer unfurl and successfully sail next year, providing the propellant for its own mission, as well as whole new space mission concepts of the future," Michael Gazarik, NASA associate administrator for space technology, said.
Also aboard the rocket with the Sunjammer will be the Deep Space Climate Observatory (DSCOVR), designed and managed by the National Oceanic and Atmospheric Administration (NOAA). That craft will orbit the Sun 900,000 miles from the Earth.
The sail is made from Kapton, a material used for the outer covering of space suits. When packed into the rocket for launch, the sail will be folded into a space about the same size as a dishwasher. When deployed, it will stretch 13,000 square feet in area. The sail is built by solar sail developer L'Garde Inc., located in Tustin, CA.
"A number of test objectives are to be checked off within the first couple months of flight. These include deployment of the sail, demonstration of vector control using sail-tipped vanes, navigation with accuracy and, finally, maintenance of the spacecraft's position at a gravitationally stable location called Earth-Sun Lagrange Point 1," Nathan Barnes, L'Garde's chief operating officer and Sunjammer project manager, said.
A solar sail the size of Texas could theoretically propel a spaceship to a nearby star system in a few decades, pushed along by a powerful laser on the Earth. One possible use for solar sails in the shorter term could be attaching them to defunct or broken satellites, to pull them out of orbit and safely away from the Earth.
Windjammer was named after a solar sail-powered ship in a 1963 Arthur C. Clarke short story.
The Ikaros probe, built in Japan, was the first craft to be propelled with a solar sail, that one just 46 feet across, when it launched in June 2010.
