Smartphones answer Nasa's higher calling
Scientists are tinkering with modified versions of Nexus smartphones to build tiny satellites that will slash the cost of space-based research
The US space agency for Nasa is known for going big: big missions, big rockets, big budgets. But nestled in California's Silicon Valley is one Nasa unit headed in the opposite direction. Its latest mission is tiny but has led to big expectations for the Small Satellite Technology Programme.
In April, this Nasa team launched three little satellites - each about the size of a coffee mug - aboard a test rocket from Wallops Flight Facility in Virginia. The probes shared two remarkable traits: all were built primarily from smartphone parts, and each cost less than US$8,000.
The mission was simple. As with Sputnik - the world's first satellite, launched in 1957 - the goal was to survive long enough to relay signals back to earth. But instead of the "beep-beep-beep" sent by Sputnik, these so-called PhoneSats (for phone satellites) broadcast much more complex data, including pictures of earth.
For six days, the probes zipped around our planet at about 87,000km/h and transmitted information about temperature and battery strength, as well as about 200 photos. Then the tug of gravity became too much, and orbits that started about 250 kilometres overhead ended in flashes of fire as they re-entered the atmosphere on April 27.
"I would say it was a success," said Bruce Yost, head of the programme. Though his team had hoped the satellites would stay in orbit for a few more days, he said the six-day mission was more than enough to prove PhoneSats have a future - perhaps as low-cost weather satellites or earth-observation platforms.
Up next are two missions designed to push the envelope even further. A launch in the autumn will test the ability of a single PhoneSat to control its own spin in orbit. Then this winter, Yost and his team hope to send a "swarm" of eight PhoneSats to measure space radiation. All nine could stay in orbit for a year or more.
The goal is to slash the cost of satellites by using technology that's sophisticated but cheap - in this case, modified versions of Nexus smartphones.
Though no one at Ames Research Centre - home to the PhoneSat programme - could pinpoint the exact genesis of the idea, Yost recalled a question often asked by Pete Worden, the centre's director.
If a smartphone has "hundreds of times more processing speed and power than the computers used to land (the) Apollo (crew) on the moon," Yost said Worden would ask, "couldn't we find a way to use something like (a smartphone) on one of our missions?"
Yost said Nasa chose the Nexus phones because information on how they work is readily available, and their "open source" Android operating system is easily manipulated. The biggest change, he said, was replacing the phones' cell radios with versions that could communicate from space and adding a bigger battery.
The test runs are intended to test the limits of smartphone technology. The team is also working toward standardising this type of satellite to bring costs come down even more. "It does have that Silicon Valley start-up kind of feel to it," Yost said.
