The team remained hopeful. They waited for a solar eclipse in 2007, when IMAGE would be in Earth’s shadow. The spacecraft was designed to reset its computers when its solar-powered battery drained, and perhaps some time in darkness would help. But it didn’t work. “It took me a while to be able to say, ‘Okay, I’m going to close the door on that and work on the next thing,’” Spann says.

Read: What a solar eclipse looks like (when you’re seeing it from Mars)

The team took some comfort in the knowledge that IMAGE had exceeded expectations. The spacecraft had performed so well after its first two years in orbit that NASA decided to extend the mission. “You’re sitting on maybe, hopefully, years of data that needs work, so that’s what you’re going to do, is just go focus on the data,” says Thom Moore, a scientist at NASA’s Goddard Space Flight Center, who worked on the mission.

Julie Webster knew exactly when her spacecraft would die, seven whole years in advance. Like all spacecraft, Cassini launched to Saturn with a finite amount of fuel. In 2010, Webster, the operations manager, and her colleagues mapped out its final years around the ringed planet. Webster was responsible for flying Cassini and, when the time came, crashing it into Saturn’s atmosphere. The loss didn’t sink in until then.

“I never know exactly how I’m going to feel about something until I get there,” Webster says. “When it was over, the whole team went around in a funk for about six months. It was just like, Oh my God, oh my God, it’s over.”

Webster has bid farewell to other spacecraft in her career, and her reaction has depended on the circumstances of their demise. She wasn’t too torn up about the Magellan spacecraft, a mission launched in 1989 to map the surface of Venus. Magellan was scraped together using spare parts from several other NASA missions, and Webster said team members wore the spacecraft out trying to get as much data as they could. “We were always trying to keep it going, so by the time it was ready to go, it was really ready to go,” Webster says.

The loss of Mars Observer, on the other hand, was traumatic. Engineers lost contact with the spacecraft just three days before it was scheduled to arrive on Mars in 1993. Investigators believe that an explosion in the hardware spun the probe out of control, but no one knows for sure what happened. Webster says it still hurts to talk about Mars Observer.

When a mission ends, scientists and engineers part with more than their spacecraft. They move on to new jobs, on new missions, and their camaraderie, sharpened over years of late nights and stressful moments, dissipates. The mission, vivid and urgent in their mind for so long, fades into a fuzzy memory. And sometimes, even then, it’s still not over.

Last year, IMAGE came back.

An amateur astronomer scanning the skies for radio transmissions detected something broadcasting at the same frequency that IMAGE once used. The former members of the mission, now scattered across different programs, confirmed the signal. After 13 years, IMAGE was awake and calling home.