Last year we learned that Android smartphones would be used to power small and relatively inexpensive PhoneSats for NASA. There are many reasons for doing so, one of the most obvious being the total cost of producing such a device.
In late February, we featured a story on the first PhoneSat that was launched into orbit. Awesomely enough, it was powered by a Nexus One. We heard all about the satellite itself, and how the phone would be used to operate it, but we never learned how NASA went about developing the thing.
According to NASA, there are strict standards that any device must pass before it is sent into space. After all, NASA needs to be sure that the device in question is tough enough to last, in the wide open field of space where no one can hear you scream.
A new report by Ars Technica details the entire process of getting these smartphones ready for space travel. In the report, emphasis was placed on the SPHERES or smartSPHERES satellites which use a Nexus S smartphone as the brain. SPHERE stands for 'Synchronized Position Hold, Engage, Reorient, Experimental satellites'. Phew what a mouthful!
These aren't your everyday satellites though, the SPHEREs are being used inside the International Space Station to investigate various electronic components and to measure radiation levels, among other things.
NASA engineers explicitly say they chose the Nexus S because of how easy it is to dismantle. According to Mark Micire, project lead of the Intelligent Robotics Group, Samsung designed the Nexus S in a way that made it incredibly easy to take apart, and that includes the internals. Luckily the individual circuit boards in the Nexus S are separate and easy to dismantle, like the rest of the device.
"You basically pop it open. It's literally six screws on the outside and it comes apart."
Micire says that other devices were not ideal for use by the project.
"We knew of other projects that were using the Nexus One, and HTC had done some interesting things in that phone that didn't make it ideal for us.
Micire mentioned that the other devices were a problem specifically because they needed them to run on AA batteries. This wasn't possible with some devices, like HTC's smartphones.
"It has to do with [HTC's] battery technologyâ€”it has to be a proprietary battery or it won't boot up."
Essentially, there was a lot of reverse engineering going on. The biggest thing the engineers had to do with the smartphone was remove the chipset dedicated to managing a proper cell phone signal. They needed the device to remain in a permanent airplane mode, but they couldn't rely on just a software toggle. Instead, they had to take the device apart and remove the chipset which powered such functionality.
Then they had to restructure the power system of the device entirely, in order to make use of two alkaline AA batteries instead of the standard lithium-ion battery pack. Furthermore, they had to play around with device drivers, software and internal sensors to make them work with the necessary peripherals on the ISS. This is where the Nexus S came in handy.
"With the Nexus line of phones, you get the full Android open source release source code baseâ€”you don't get that with a lot of the other Android platforms out there."
Micire said that the open source approach to the design of the Nexus S allowed his team the appropriate resources to get the phone working with the necessary components in both the SPHERE satellite module and the ISS.
Of course, there is a lot of other advanced hardware and software tweaks that need to be done to a smartphone in order to make it truly space ready. I would suggest taking a look at the source below for more information, it's certainly an entertaining read.
Source: Ars Technica