SMART Nav: Giving Spacecraft the Power to Guide Themselves

In person, SMART Nav doesn’t look like much. It’s in a metal square that’s laced into a web of soldered wires, resistors and diodes on a circuit board. In fact, technologically speaking, it’s a microprocessor that isn’t even state of the art. It has the same power as a PlayStation 1 from 21 years ago. Your smartphone has more power.

“If you use the latest and greatest electronics that pack millions and millions of transistors into them, it turns out the device becomes more susceptible to radiation,” explained David Carrelli, a guidance, navigation and control analyst at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, who served as the guidance and control lead for majority of the development of NASA’s Double Asteroid Redirection Test (DART) spacecraft. “It can’t fly in space without a lot of modifications.”

But what SMART Nav does is far from antiquated. It’s unlike anything used on a spacecraft before it.

Short for Small-body Maneuvering Autonomous Real Time Navigation, SMART Nav is a set of computational algorithms on DART, a mission that will test our ability to redirect one of these space rocks by striking it with a spacecraft. It’s a method that one day could protect Earth from catastrophe. And for the spacecraft’s last four hours of existence — a period called the terminal phase — SMART Nav, with the rest of DART’s guidance and navigation system, will independently find Dimorphos and guide the spacecraft into it.