Engineers at Nasa’s Ames Research Center - and amateurs around the world - are ready for their latest smartphone-powered satellite project to reach the International Space Station in late March. Astronauts on the ISS will release the satellite into orbit in the spring.
The PhoneSat project is part of Ames’ “area of ingenuity” in low-cost missions. The center’s engineers look at ways adapting off-the-shelf consumer technology benefits spacecraft design:
- Mass-production lowers the cost dramatically compared to small-volume space hardware.
- The smartphone’s manufacturer has already integrated the many subsystems - processor, memory, sensors - eliminating much of a satellite project’s design and test work.
- The standard Android operating system and its programming tools simplify the space project’s software development work.
Nasa’s first three PhoneSats reached orbit in early 2013. Two PhoneSat 1.0 satellites used an HTC-made Nexus One smartphone to take pictures of Earth. PhoneSat 2.0 used a more powerful Samsung-made Nexus S to test a stabilization system based on the smartphone’s positioning sensors. These early tests showed that smartphone technology could survive launch and conditions in space as well as lowering the cost of satellite designs. The cubesatshop lists a Pumpkin CubeSat Kit for €7,500 (over $10,000). Thanks to the economics of consumer technology, each PhoneSat’s hardware cost less than $3500.
But Nasa won’t be stocking up on satellite components at Wal-Mart any time soon. The November 2013 PhoneSat 2.4 mission suffered from a series of solar flares that caused the smartphone to repeatedly restart. The satellite still broadcasts a signal from orbit because its space-qualified communications and power systems continue to work. PhoneSat 2.5 adapts the lessons learned from the previous missions. Rather than place the entire smartphone, Nasa’s engineers only used the components needed for the satellite’s mission. Part of the mission’s objectives is to see if the new design will survive longer in the radiation environment of low-Earth orbit.
What does the PhoneSat project mean for amateurs? The mission team at Ames depended on amateur radio operators to get the PhoneSats’ data. The low-bandwidth signal from each PhoneSat kept the satellite from transmitting a full image file from the smartphone’s camera while above any particular point on Earth. Ham radio operators around the world each received a small number of data packets and submitted the data to Nasa’s phonesat.org website. The Ames engineers used the amateur-collected data to reconstruct the pictures of Earth.
The PhoneSat project is also validation for the amateur near space explorers who for years have used smartphones to control their high-altitude balloon systems. You can see video and slides from Nasa’s presentation to the 2011 Summer CubeSat Developers Workshop that describes their near-space testing of the PhoneSat. Learning from Nasa’s work will help make amateur near space flights more reliable.