Off The Shelf
A version of this article appears in the August 4 edition of Aviation Week & Space Technology.
Terrestrial smartphone technology, based in part on government space research, is finding its way back into space as low-cost, rapidly evolving processors, cameras, GPS receivers and other gear used in bulk by the burgeoning smallsat movement.
In California’s Silicon Valley, where the lifetime of a state-of-the-art smartphone is about one year, engineers at’s have literally been plugging smartphones into spacecraft to get the most capable hardware into space quickly.
That approach has migrated into the commercial sector, where groups of Ames alumni are applying it to constellations of low-orbit smallsats that they are evolving toward the day when they can provide daily remote-sensing updates over the entire Earth.
“We don’t actually use any phones anymore, but we do use consumer electronics, and all the chips that are in phones,” says Will Marshall, one of the founders of Planet Labs Inc. and a veteran of’s PhoneSat project at Ames. “We go right to the core and design all our own circuit boards, it’s all our own technology. But we leverage all the transistors and the radio components and the amps and the resistors, we leverage all the developments that are happening. We take the latest CPUs [central processing units], the latest flash drives, the latest sensor systems and stuff [them] into our little box.”
That approach has attracted the attention of the venture capitalists and angel investors on Menlo Park’s Sand Hill Road, the Wall Street of Silicon Valley. So far, Planet Labs has raised $65 million and launched 71 of its tiny “Dove” satellites. Competitor Skybox Imaging had raised more money, but launched fewer of its larger satellites, when it was acquired by Google in June for $500 million (AW&ST June 16, p. 34).
has been an incubator for the technology turnaround, pulling technology originally developed for traditional “big” space back into the small-space arena after it was adopted and mass produced by the private sector. Smartphones are the nexus of the shift, and it started at Ames.
Marshall, who is CEO of Planet Labs, remembers one of his NASA bosses at Ames waving his cellphone around during meetings about spacecraft design and asking “Why are you guys making it so complicated? You have everything you need for a satellite in this smartphone.”
“Eventually we took him seriously,” says Marshall of the PhoneSat project.
The first PhoneSat was literally just that—an off-the-shelf smartphone launched into space inside a 1U cubesat.
“They picked a phone that uses open-source software [a Nexus One running Android], which they felt has the potential for allowing multiple sources of application software,” says Andy Petro, program executive for NASA’s Small Satellite Technology program in the Space Technology Mission Directorate.
The Phonesat 1.0 configuration ran on battery power, and used the phone’s camera to photograph Earth for the week that it lasted in space after its April 21, 2013, launch on the firstAntares launch vehicle to fly (which also carried the first Dove for Planet Labs). The spacecraft famously used a length of yellow tape measure as its UHF radio antenna.
“For the 2.0 version they took the electronics out of the mobile phone box and build it up a little bit more like a series of circuit boards inside the cube,” Petro says. “We immediately had contact with it after launch.”
That spacecraft was among 28 cubesats launched in November 2013 as secondary payloads on an Orbital Sciences Corp. Minotaur vehicle. Equipped with solar cells to recharge its batteries, the spacecraft worked well at first, but lost functionality later in its mission. Petro says radiation effects are the suspected cause, but the issue is still under study.
The same types of problems cropped up on PhoneSat 2.5, which was launched on a Falcon 9 from Cape Canaveral in April. That spacecraft includes a rough pointing capability provided by reaction wheels driven by small electric motors the project acquired from a dental-drill supplier.
Smartphones have supported other space applications recently. They include robotics experimentation inside the International Space Station using the Synchronized Position, Hold, Engage, Reorient, Experimental Satellites (Spheres) testbeds. Crewmembers on board the station have used the “Smart Spheres” to evaluate robotic systems that could one day drive free-flying “helpers” to take over routine maintenance chores from humans.
Basically a set of basketball-sized spacecraft powered by compressed gas, Smart Spheres are used to test various guidance, navigation and control software packages uploaded from the ground for testing. But the processors in the Spheres units are too old to handle advanced robotics software efficiently.
“The processing power on Spheres as a core system is something that has been around quite a long time now, probably 10 or 15 years, not nearly powerful enough to run the kinds of robotics software algorithms we take for granted on every other robot platform in the world today,” says Terry Fong, who runs the Intelligent Robotics Group at NASA Ames. “So our approach for addressing these limitations of Spheres as a legacy system was to add a smartphone to it. Just over three years ago we upmassed the Google Nexus S, an Android-based smartphone. It gives us a lot of computational horsepower in a small package.”
The phone was literally kluged onto the side of one of the Spheres units (see photo), bringing along its 1-GHz Cortex A8 processor, 512 MB of RAM, a 16-GB flash memory, 3-axis gyros and accelerometers, and two color cameras. Fong and his team used that capability to study the use of Wi-Fi signal strength inside the station as a way for a robot to navigate autonomously through the modules.
The project already has outgrown that capability. Now the group is planning to use a Google “Project Tango” prototype with a structured lighting sensor drawn from X-Box Connect technology to improve the robot’s ability to find its way around.
“If any of you remember the Nexus S, it was state of the art about four years ago, and then it was not state of the art about three years ago, which is sort of a lifetime in the smartphone world,” Fong told an ISS utilization conference in June.
At Planet Labs, the philosophy is to launch early and launch often, building in upgrades with each “flock” of the Dove spacecraft it sends to orbit and testing them there. The 28 Doves launched on an Antares July 13 for deployment from the “porch” of Japan’s Kibo module (see page 19) were “Build 8” in the Planet Labs design sequence, while the 11 launched on a Russian Dnepr repurposed intercontinental ballistic missile June 19 were the “Build 9” variant. With the ultimate objective of a nanosat constellation able to update overhead imagery of every point on Earth every day (see photos), the company has moved on to Builds 10 and 11 since those launches, Marshall says.
“We think there are strong humanitarian uses for this data and strong commercial uses,” says Marshall. “Imaging having the data soon after flooding or fire, or earthquake, or the plane crash in the Ukraine. If we can have that data, we can help those relief operations faster. And we also have the data from the day before. One of the things we saw in Haiti and the tsunami in Japan is that people scrambled to get imagery in the immediate aftermath of the disasters, but no one had the image from the day before, and it turned out Haiti had changed a lot since the last image taken of that area [was several years ago]. We would be able to have an apples-to-apples comparison.”
One issue Planet Labs, Skybox and others will have in controlling the data flow from space may be helped by the next phase of the PhoneSat effort at NASA. Known as the Edison Demonstration of Smallsat Networks (EDSN), the idea is to launch eight 1.5U cubesats designed to handle communication with the ground autonomously.
“You’ve got a bunch of small satellites, each taking science measurements,” says NASA’s Petro. “Rather than having to have a ground system that’s talking to each of these satellites, which as you can imagine as you get beyond eight to dozens or a hundred, it’s really not so practical to do that. You lose the benefit of the low-cost mission if you need a huge expensive ground infrastructure to deal with them. So the idea is they each talk to each other, they share the data among themselves, and then one of them serves as the relay to the ground.”
The EDSN constellation, set to fly from Hawaii Nov. 14 on a rail-launched Super Strypi rocket, will measure radiation across space as a simple test of the inter-satellite link in scientific data-collecting. All of the spacecraft can collect and send data to the ground, and the cross-link architecture will allow an operational system to degrade gracefully, continuing to collect and send data until only one is left.
Marshall says he and other Planet Labs engineers were involved in early planning for the EDSN project, and are monitoring it for possible application in their own constellation. In the meantime, the company is upgrading its ground-station network as it evolves toward its daily update goal.
Planet Labs is located in San Francisco, where it can maintain close contact with technology and business developments in the Bay Area. Petro, who is based at NASA headquarters in Washington, says that sort of technological churn between terrestrial and space applications in the private sector illustrates how spending on government research and development can find its way into the broader economy.
“It was government investment over decades in the past that created this electronics technology we have now that makes possible all of these wonderful consumer products we all use,” he says. “We can now go back and take advantage of that huge investment made in the past—coupled with the efficiency of the mass production for the consumer products—to get those very high-tech items at extremely low cost compared to typical prices today.”