NASA Solar Sail Vanishes in Space

NASA's solar-powered sail craft NanoSail-D is missing, and scientists don't know whether it's adrift in space or was never ejected in the first place.

The nanosatellite, roughly the size of a loaf of bread, was supposed to be ejected from its 400-pound mother satellite last Monday—and all signs indicated it did. But it was also supposed to check in 3 days later, when the 8-pound canister would blossom into a solar sail 10 square meters and thinner than a human hair. When the appointed time came and NASA scientists got no signal, they knew something had gone wrong, NASA announced on Friday.

NASA operates ground instruments to pick up those kinds of signals all over the world, according to Marshall Space Flight Center media officer Kim Newton. The silence suggests the tiny satellite may never have left home at all. But Newton says there are no firm hypotheses.

Bill Nye, executive director of the Planetary Society in Pasadena, California, thinks three things could have gone wrong. One, the battery may have been too small and ill-equipped to deal with the cold of space. Two, NanoSail-D could have not ejected at all, as NASA speculates. Or three, the sail could have failed to unfurl.

"The key is to make it go out slowly, even in the inertial zero-gravity situation of space," says Nye. "It wouldn't be surprising, based on the rudimentary nature of the design, that it went out fast and tangled."

NanoSail-D blasted into orbit in November as part of NASA's Fast, Affordable, Science and Technology Satellite (FASTSAT), which is also carrying five other experiments. It marked NASA's second attempt at launching a solar sail. The first one never made it to orbit due to a failure at launch.

Before its untimely disappearance, scientists hoped NanoSail-D would help them test a low-cost way of pulling old satellites back to Earth. Because it needs only photons from the sun to propel it forward, it saves money on fuel. Cramming the fragile sail into a small canister protects it from being ripped to shreds by Earth's atmosphere.

NASA isn't the only organization to experience these kinds of headaches with solar sailing. The Planetary Society made a similar effort in 2005 with Cosmos 1 that was lost in a rocket mishap. Now they're working on their own second shot, Lightsail-1. Meanwhile, Japan's solar sail IKAROS, launched last May, became the first successful attempt at solar sailing to date, deploying its sail, confirming photon propulsion and performing attitude control tests. A review committee is likely to declare the mission a complete success later this month.

Although Nye is optimistic about the future of solar sailing in general, he's more reserved about this particular NASA mission. "Maybe they will recover it. But I've got a feeling it's lost."

*This article has been corrected. It originally identified IKAROS as the Japanese probe that missed Venus earlier this week, which was actually Akatsuki.

Posted in Space