A San Francisco–based company called Planet Labs announced plans yesterday to launch 28 mini-satellites in a ring around Earth as early as December of this year. The company aims to provide frequent snapshots of the planet, allowing users to track changes—from traffic jams to deforestation—in close to real time.
Some existing commercial satellites focus on taking high-resolution images of particular regions for their customers, using technology that can discern details smaller than a meter across, but the demand for these services means it can take days or weeks to get a desired image. And government science satellites that image the entire planet do so at relatively low resolution, showing details tens or hundreds of meters across.
Planet Labs’ satellites will use moderate resolution, making out objects three to five meters wide. But thanks to the sheer number of satellites, the fleet should be able to take more frequent snapshots of the globe. The exact frequency has yet to be decided, but “it is going to be something the industry doesn’t have today,” says company cofounder Robbie Schingler, a former chief of staff for NASA’s Office of the Chief Technologist.
With that quick turnaround time, online maps could be updated more frequently, and environmental organizations could gain unprecedented monitoring capability. “We can track deforestation or the ice caps melting,” says Will Marshall, another company founder and a former NASA scientist. “What we’re trying to do is monitor the planet on a really regular basis so people can help take care of it in a sustainable way.”
Planning such a large fleet is possible because the satellites are small and relatively inexpensive. Their design uses 10-centimeter-wide boxes called CubeSats, standardized modules that for the last 10 years have been fitted with instruments and launched into space either singly or joined together like Legos. CubeSats began as university teaching tools, but advances in consumer electronics, such as smartphones that fit ever more power into ever smaller packages, have made them increasingly viable as the basis for more ambitious business plans.
The company hasn’t said exactly how many CubeSats will go into each satellite in the fleet, but the first two test satellites it launched in April, called Dove 1 and Dove 2, were each made up of three. Two more, at least one of which is also a “3U”—or three-unit—satellite, are set to launch in November.
The company plans to launch all 28 satellites in its new constellation together on an Antares rocket, a new launcher built by the Virginia-based Orbital Sciences Corporation. After the launch, which could take place as early as December, the satellites will form a tilted ring around Earth, “like a string of pearls,” says Marshall. There they will orbit at an altitude of 400 kilometers, powered by solar panels.
The satellites will send their images to at least three ground stations—two in the U.S. and one in the U.K. The data will be processed and uploaded for use by customers almost immediately. “If an event happens, like a fire, we have fresh imagery … to understand what’s happening,” says Schingler.
The satellites, which have no propulsion systems, should stay in orbit for two to five years before losing speed to atmospheric drag so that they fall toward Earth and burn up, the company says.
Kerri Cahoy, an assistant professor of aeronautics and astronautics at MIT, is skeptical of some of the company’s claims. Downloading and processing the data from 28 satellites will be very difficult to do in real time, she says, though she is glad that someone is attacking the problem. And she says the atmosphere is thick enough at 400 kilometers to pull the satellites out of orbit relatively quickly if they lack propulsion systems to boost themselves higher. “I’d be very surprised if they were up more than a year,” she says.
But it might not matter so much if they do die prematurely, since each modest module will cost far less than a typical imaging satellite used today, which carries a price tag in the hundreds of millions of dollars.
Planet Labs is not the only startup trying to get into the Earth-observation game. A Silicon Valley firm called Skybox Imaging aims to launch at least 24 satellites that will be able to take high-definition video of any spot on Earth and capture details just one meter across. Each of its satellites should cost about a 10th as much as a traditional one (see “Cheaper Satellite Pictures”).
But Planet Labs’ satellites should be even cheaper, an advantage that helped generate the first deposit into the company’s $13.1 million pot of seed money. Steve Jurvetson, managing director of the venture capital firm Draper Fisher Jurvetson, says he’s “seen at least a couple of different companies” that hope to improve the price performance of satellites by a factor of two to 10. But, he says, “when we saw Planet Labs, we saw something that was quite dramatically better.”