Tiny Satellites, Big Universe

Small spacecraft, shaped by the forces that shrunk your cellphone, are changing the way we observe space and understand our home.


After a summer of wildfires, hurricanes, and nuclear threats, it isn’t hard to see the value in being able to surveil the Earth with daily—or even more frequent—updates. But traditional satellites, which cost hundreds of millions of dollars, have orbits that mean they may not see the same target for a week or more. So an Earth-imaging company called , in San Francisco, is doing something different. In the past year, it has sent nearly 150 satellites into space, including a record 88 at once from India on Valentine’s Day. That should be unthinkable, but Planet is using CubeSats, an emerging type of small satellite made possible by the miniaturization of electronics and sensors, like those in smartphones, that are creating new possibilities to use space technology for social and economic purposes.

Universities are able to develop, build, and launch 1U CubeSats for less than $100,000.

CubeSats are based on a one-unit (1U) standard cube the size of a grapefruit—10 centimeters in all dimensions, and weighing up to 1.33 kilograms. (Planet’s Dove satellites are called 3U CubeSats because they have one longer side of 30 cm.) They can fly as extra payload on an existing mission, taking up the space left over on a rocket after, say, SpaceX’s resupply for the International Space Station has been loaded up. And organizations with less funding than SpaceX can use them: Universities are able to develop, build, and launch 1U CubeSats for less than $100,000.

Planet’s Dove satellites are ejected from the ISS’s spring-loaded CubeSat deployer, which shoots satellites into orbit.

Much like smartphones have collectively changed the way we communicate and interact, CubeSats have demonstrated that constellations of small satellites provide services not easily achieved with traditional spacecraft. As Mike Safyan, senior director of launch and ground station networks at Planet, says, “Once those large networks of small sensors are deployed, the scope of coverage and timeliness of data collected can be greater than any single, large satellite mission.” CubeSats are also relatively disposable, so it’s possible to learn from flight experience and quickly make design changes. Planet’s 88-CubeSat flock was its 13th generation, and allowed it to achieve its goal of daily imaging of most of Earth. CubeSats also serve as proving grounds for new technologies: In 2018 the Planetary Society, a nonprofit founded by Carl Sagan and led by Bill Nye, will launch the LightSail 2 mission to validate novel propulsion, using a solar sail to alter a CubeSat’s orbit. Upcoming NASA CubeSat missions will qualify a variety of electronics for use in commercial missions—and deep space.

Soon CubeSats will venture beyond Earth’s orbit. , launching in 2019, will circle the moon and peer into its shadowed craters. Traveling millions of kilometers alongside NASA’s InSight mission to Mars in 2018 will be a pair of experimental CubeSats called MarCO. They’ll separate from the lander prior to touchdown to augment the lander’s data. Going forward, it’s likely we’ll see CubeSats fly alongside other interplanetary missions, hitching rides to try inventive new technologies, often on missions of opportunity. Though small and modest, in their way CubeSats are the perfect expression of the ingenuity and adaptability that drive our ventures further and further from home.

is an engineer who helped land the Curiosity rover. Opinions are his own and not endorsed by his employer, NASA’s Jet Propulsion Laboratory. This story appears in the December 2017 issue.

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