When the Error Message Comes From 50 Million Miles Away

…spacecraft engineers have to get creative.

The Galileo spacecraft was already far from Earth when problems cropped up with its antenna. (NASA)

Deep Space 1


In 1995, NASA kicked off the New Millennium Program, an initiative to test technology in space to benefit future space science research. The first platform was Deep Space 1, which launched in October 1998 with innovative systems like autonomous navigation, miniaturized cameras, and an ion propulsion engine that needed to prove its usefulness for long-duration missions.

The primary 11-month technology demonstration went well, according to NASA project manager Marc Rayman. Then the mission team sent Deep Space 1 off on a two-year mission to fly by the comet Borrelly (pictured) in September 2001. But just two months into the trip, the spacecraft’s star tracker, a critical space navigation tool, failed. The initial reaction from NASA officials was that the incident was fatal to Deep Space 1. “But when you have a team of passionate and ambitious explorers,” Rayman says, “you don’t give up easily.”

Indeed, the team saw the situation as an entirely new test for their suite of equipment, and dreamed up ways to jury-rig the systems to replace the star tracker. After seven months, engineers had developed new command software that would make use of the miniature camera and the autonomous navigation system—transmitting the software update to the spacecraft, now a couple of hundred million miles away, at a painfully slow rate. At one point, the data link to the spacecraft was interrupted, causing everything that had been uploaded up to that time to be lost. That was the lowest point for Rayman and his team, he says. Still, they started again.

On September 21, 2001, Deep Space 1 flew into the icy dust cloud of Borrelly and took the first images of the nucleus of a comet.

Freelance writer Zoe Krasney lives in New Mexico, surrounded by the history and future of aviation and space exploration.

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