The Samsung Nexus S Android smartphone served as the brain for three sphere-shaped floating robots as part of a previous NASA project.The Human Exploration and Telerobotics Project (HET) placed Samsung Nexus S smartphones into small free-flying satellites. The volleyball-sized Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) aren't actually traditional satellites.

New techniques of sensing and modeling the ISS are tested by HET with the help of the Nexus S Android smartphones. Since the SPHERES are equipped with the Nexus S phones, they can move around by themselves. Researchers control them from Earth using high-level commands.

"By connecting a smartphone, we can immediately make SPHERES more intelligent. With the smartphone, the SPHERES will have a built-in camera to take pictures and video, sensors to help conduct inspections, a powerful computing unit to make calculations, and a Wi-Fi connection that we will use to transfer data in real-time to the space station and mission control," said DW Wheeler, lead engineer in the Intelligent Robotics Group at Ames.

Thanks to the Nexus S Android phones, hardware upgrades for SPHERES are made easier. Prior to that, researchers had to have new equipment flown to the ISS.

"Android is a very important feature for our team. The availability of the Android source code allows us to customize the smartphone to be used as a compact, low-cost, low-power computer, rather than just as a phone," said Mark Micire, a software engineer in the Intelligent Robotics Group.

To prepare the two Nexus S devices that are currently being used on the ISS in space, some adjustments had to be made including hacking their hardware. The research team chose the Nexus S devices citing that it would be easier to take apart.

They then forced the smartphone into permanent airplane mode so that it wouldn't interfere with the electrical systems on the ISS. As ARS Technica reported, instructions on how to disassmble the phones were used to help the team find the internal chip that needed to be removed to disable the device's cellular capabilities. "The phone is none the wiser. It just thinks it doesn't have cell phone service," said Micire.

To get lithium-ion batteries approved for use on the ISS would have taken two years. Researchers didn't want to wait that long and Alkaline batteries were already certified for space travel. The team made a custom battery pack for the Nexus S phones using six AA batteries. The packs were then wrapped in a felt-like material to absorb any electrolyte leaks that may occur. Velcro patches were used to affix the battery packs to the SPHERES.

There are currently two Nexus S smartphones on the ISS and robots will someday become an integral part of the operations of the space station with the help of Android.