It's hard not to get freakishly excited when science fiction becomes scientific fact -- especially when the origins of that science are rooted in Star Wars.
Think back, young Jedis, to the scene where a fresh-off-Tatooine Luke Skywalker is honing his light saber skills under the tutelage of Obi-Wan Kenobi. A round, floating robot called a remote helps Luke practice his Force-finding mojo. Now, NASA is running experiments with miniature satellites, or nanosatellites, that were inspired by that fictional robot.
Roughly the size of a soccer ball, these robots that fly freely in space are called Spheres (which is short for Synchronized Position Hold Engage Reorient Experimental Satellites). Star Wars connection aside, there's another remarkable detail about Spheres: they're powered by smartphones, specifically a Google Nexus S.
David Korsmeyer, director of Engineering at NASA Ames Research Center, said that using a smartphone covered all the bases. "You've got the accelerometer, you've got a high-end computer, you've got a magnetometer, you've got a camera... location, all the comm, all the memory. We thought why not just take that and see how much of this can be turned into an actual satellite," he said.
By using off-the-shelf technology, NASA reaps key benefits. It saves researchers the time and effort of building the same technology from scratch and whenever a new smartphone model is released, NASA can easily upgrade with a simple phone swap. The greatest advantage, though, is the cost savings.
Mark Micire, the engineering manager for the Spheres lab at NASA Ames, estimates that to build and fly a single Spheres unit runs hundreds of thousands of dollars, whereas doing the same for a traditional satellite would be a multimillion-dollar endeavor.
During a recent visit, CNET got a first-hand look at how Spheres move. We've all seen robots that are remotely controlled and can sense their location, but accomplishing that same task in zero gravity is much more complex. Micire explained how carbon dioxide tanks, thrusters, and a digital signal processor enable Spheres to "do the hard math to figure out what combination of thrusters it should fire." To track its whereabouts, Spheres has an onboard beaconing system of sorts that includes infrared sensors.
"It's almost like GPS, but it uses sound. And so with those sensors, it's able to triangulate and lets it know not only where it needs to go, but where it is right now," Micire said.
NASA is experimenting with Spheres on the International Space Station to establish telepresence between mission control and the station. NASA can commandeer Spheres from Earth to inspect parts of the station. That's a particularly handy capability when flight crew are sleeping, for example. Micire described another project that researches how fluids work in microgravity. "So they have two Spheres that are connected to this large vessel. It's filled with water and it has cameras on it. And we're using the Sphere to move that vessel around, and so in that case the Sphere is kind of the tugboat."
Another NASA nanosatellite also takes advantage of smartphones: PhoneSat. The device is only the size of a tissue box but has modular capabilities. Says Korsmeyer, "You can't do as much with a small cube satellite like this on a big spacecraft, but if you got tens of thousands of them you can do a phenomenal amount."
The PhoneSat is gearing up for its space debut. Three PhoneSats are scheduled to launch in late April, but these nanosatellites could be launched individually, or in larger groups. Thanks to its modular nature, a group, or satellite swarm, working cooperatively could be reconfigured on the fly. And if one malfunctioned, another could take its place. These devices could be used to test technologies for space flight and even for moon exploration.
And if you're concerned that it's becoming a bit crowded up there in space, Korsmeyer offers an assurance. "There's no debris that gets to the ground at all," he said. "It's all light metal and aluminum. And if you've ever dropped your phone, just imagine it burning up in the atmosphere."