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GCN : May 2013
34 GCN MAY 2013 • GCN.COM EXPLORING SPACE IS an expensive proposition, but perhaps it doesn t have to be that way. That s the think- ing behind NASA s PhoneSat program, which successfully launched three cell phones into space April 21, with the goal of using them as inex- pensive satellites. Earth s newest satellites cost no more than $7,000 each, and can go as low as $3,500 depending on how they are configured. For this mission, the satellites com- prise modified Google-HTC Nexus One smart phones running the Android operat- ing system. They have been equipped with protective cages, high-capacity batter- ies and a new transmitting antenna. This all fits within a four-inch cube. Additionally, the phone s ability to receive and transmit calls and text messages has been disabled. "Smart phones o er a wealth of potential capabili- ties for flying small, low-cost, powerful satellites for at- mospheric or Earth science, communications or other space-born applications," said Michael Gazarik, NASA s associate administrator for space technology in Washing- ton, D.C. The launch is being used as a technology demonstration program, to see if standard o -the-shelf smart phones can be modified to work in space. As such, the phones on this mission have been programmed to transmit a variety of data types to see what works and what needs more work. The phones are even trying to use their standard on-board cameras to take pictures of the Earth in sections, which will be stitched together into a one large image. NASA is asking for help from amateur radio operators around the world, who are needed to intercept the sig- nals the phones are sending. The phones are operating under the call sign KJ6KRW on a frequency of 437.425 MHz with a modulation of AX-25 AFSK and a data rate at 1200 bps. Signals include audio files, picture files and data bursts. Anyone who receives a signal can send it into NASA, and the file, user name and location of the radio will be posted online. The two PhoneSat 1.0 satellites, named Graham and Bell, transmit every 28 and 30 seconds. The slightly more advanced PhoneSat 2.0 beta satellite, named Al- exander, transmits every 25 seconds. A map shows where they are above the Earth and which stations have already received data packets. NASA o cials said that they expect the satellites to remain active for about two weeks, before their orbits decay and they burn up in the atmosphere. This isn t the first time NASA has experimented with nanosatellites. It has used the Nexus S smart phones to operate prototype robots on the International Space Sta- tion. DARPA, meanwhile has an e ort underway to build clusters of smaller satellites that could function as one. So far, the PhoneSat program seems to be going well. NASA says that amateur radio operators have already intercepted and recorded over 200 signals from the cell phone satellites. If they continue to perform well, NASA says PhoneSat models could be used for climate research and other projects that require an orbiting satel- lite, but which in the past required expensive equip- ment that could delay impor- tant information gathering and which might have been deemed cost prohibitive. • NASA'S SMART-PHONE SATELLITES LAUNCH NEW ERA IN SPACE COMMUNICATIONS BY JOHN BREEDEN II EMERGING TECH NASA's prototype PhoneSat 1.0, built around HTC's Nexus One smart phone and running Google's Android OS, during a high-altitude balloon test. NASA AMES RESEARCH CENTER