MIT: Nano Satellites and Ground Sensors: Working Together for Disaster Relief and Agriculture
A swarm of small satellites could give critical infrastructure an Internet connection that never goes down.
WHY IT MATTERS
Being able to collect data in emergency situations where conventional networks are cut off could be widely useful.
Anthony Previte, CEO of the space company Terran Orbital, was set on the path to his company’s latest project by a nurse he encountered amid the chaos of 9/11, one block north of Ground Zero.
She was running frantically down the street because the nearby hospital had run out of fuel oil. With most cell-phone batteries depleted and landlines knocked out, the only way to call for more was on foot. Previte got to thinking that important equipment like generators should have ways to communicate anytime, even after a disaster. Today he’s working to make that possible by launching multiple constellations of “nano satellites” designed to provide small, battery-powered sensors with a cheap data connection that never goes down.
Previte says his system will have many civilian and commercial applications and save lives in the wake of natural disasters or terrorist attacks. “If every generator has a sensor on it that reports back to a satellite, then whoever is in charge—FEMA, the government, the military—can move fuel around, with intelligent decisions,” he says.
More and more commercial and industrial equipment is becoming connected to data networks so they can be managed more efficiently, forming what’s known as the Internet of things. Terran’s always-on connections might make that approach more dependable.
Satellite Internet connections available today are mostly targeted at people, not machines, and they’re expensive. They use large satellites parked in geostationary orbits roughly 36,000 kilometers over the equator, meaning that significant energy is required to reach them with a signal from the ground.
Terran is launching small satellites that orbit at only 600 kilometers. That lower altitude makes it practical for low-powered, even disposable, sensors to use a satellite data link, says Previte.
The connection is designed to be more reliable than it is fast. The U.S. army is to use Terran sensors to track vehicles and troops that transmit at tens of kilobytes per second. But Terran expects lower-powered sensors to send up data at about a tenth that speed.
In addition to aiding in disaster relief and tracking shipping containers, planes, and boats, Previte envisions the sensors being used for environmental monitoring. For example, they could be dropped out of a helicopter or drone into a growing oil spill, or onto an active volcano to track lava flows. Terran anticipates significant interest from farmers, who could place sensors in fields or even around the necks of cows.
Previte estimates that Terran can build the disposable, low-powered sensors in bulk for roughly $80 each. Customers will pay a subscription on top of that for their connections. Terran will also sell complete satellites to customers who want the exclusive use of one. “It used to be $400 million for a satellite,” says Previte. Terran will be able to offer them for figures in the low millions of dollars, he says.
In addition to its deal with the U.S. Army, the company says it already has commercial clients, but none that are prepared to disclose their relationship publicly. Deploying a constellation of nano satellites requires 18 to 36 months of lead time, and these companies want to surprise the competition, says Previte.
Terran, which serves as a consultant to integrate satellite payloads and helps with mission control operations, will say that it supported the launch of nine satellites in 2014 and 10 so far this year. The company has also built six small satellites from scratch in 2015.
Jordi Puig-Suari, Terran’s chief science officer, is one of two inventors of the CubeSat, a generic blueprint for miniaturized satellites that are typically a cubic liter in size. Different payloads can be installed in a CubeSat using off-the-shelf electronic components (satellites traditionally have custom-built electronics). Further cost savings come from the way the small satellites can be fitted into unused space inside rockets launching larger satellites or space vehicles.
Kerri Cahoy, an assistant professor of aeronautics and astronautics at MIT, said Terran’s model makes it distinct from most satellite companies.
The development of smaller, cheaper satellite technologies in recent years has led many companies to explore new ways of using low Earth orbit (LEO) satellites.
Many focus on remote imaging—for example, to gather regular photos or infrared imagery. But Cahoy says LEO satellites should make a good low-cost communications network. “It sure beats trying to figure out how to connect a large number of distributed ground sensors to a cable or wire-based ground network,” she says. And satellites can more easily cover large swaths of territory than cellular or Wi-Fi networks, which need many base stations.
By A. Rosenblum