NASA’s Data Plan

Posted on July 23, 2013


BellPhoneSatOn April 22, 2013 NASA launched three nano-satellites into a near-earth orbit. The three satellites dubbed Alexander, Graham, and Bell were powered by commercial smartphone technology.

The mission, according to the Phonesat website, was a  demonstration designed to show how commercial technology could be incorporated into spacecraft.

“The project is based around Commercial Off-The-Shelf (COTS) electronics to provide functionality for as many parts as possible while still creating a reliable satellite,” the site says.

The satellites incorporated Google-HTC Nexus One smartphone’s running the Android operating system – with talk and text deactivated. According to NASA’s website, smartphones have an abundance of technology that can be used as the main flight avionics on a functional satellite.

“NASA’s off-the-shelf PhoneSats already have many of the systems needed for a satellite, including fast processors, versatile operating systems, multiple miniature sensors, high-resolution cameras, GPS receivers and several radios,” the site says. “The smartphone acts as the satellite’s onboard computer. Its sensors are used for attitude determination and its camera for Earth observation.”

An external battery pack, and a radio for transmitting data back to earth, were added to the phone. All the electronics were packaged in the 10 cm x 10 cm x 10 cm footprint of the cubesat platform. Using commercial technology kept the cost of each satellite between $3,500 and $7,000.

During their week-long flight the satellites radioed their “health status” back to the NASA ground crew. They also used the smartphone’s cameras to take pictures of the earth from the vantage point of their low earth orbit. The data was transmitted back to earth in AFSK (1200 bps) modulation, AX.25 packet coding format.

Amateur radio operators were asked to track the satellite, receive the packets of data and upload them to the phonesat website. The resulting composite images, with varying amounts of detail, show the images the satellite were able to capture before deorbiting and burning up in the atmosphere one week after being launched.

Composite images from the Graham and Bell satellites can be seen on the phonesat website.

Posted in: Transmission Art