NASA To Test New Solar Sail Design

 From Popular Science (h/t Instapundit): "NASA will unfurl a 860-square-foot solar sail from within a microwave-sized cube." The experiment was launched into orbit a couple days ago. 

    The real story here is not the solar sail, but the solar sail boom that holds the sail and provides rigidity: "Engineers have already demonstrated the principles [of solar sails] before, but NASA’s new project will specifically showcase a promising boom design constructed of flexible composite polymer materials reinforced with carbon fiber." 

    Although delivered in a toaster-sized package, ACS3 will take less than 30 minutes to unfurl into an 860-square-foot sheet of ultrathin plastic anchored by its four accompanying 23-foot-long booms. These poles, once deployed, function as sailboat booms, and will keep the sheet taut enough to capture solar energy.

    But what makes the ACS3 booms so special is how they are stored. Any solar sail’s boom system will need to remain stiff enough through harsh temperature fluctuations, as well as durable enough to last through lengthy mission durations. Scaled-up solar sails, however, will be pretty massive—NASA is currently planning future designs as large as 5,400-square-feet, or roughly the size of a basketball court. These sails will need extremely long boom systems that won’t necessarily fit in a rocket’s cargo hold.

    To solve for this, NASA rolled up its new composite material booms into a package roughly the size of an envelope. When ready, engineers will utilize an extraction system similar to a tape spool to uncoil the booms meant to minimize potential jamming. Once in place, they’ll anchor the microscopically thin solar sail as onboard cameras record the entire process.

There's more about the mission, so be sure to read the whole thing.