STEVE INSKEEP, HOST:
Scientists may be nearing the end of a passionate quest to reconnect with a vintage NASA spacecraft. For decades, that satellite has followed a long, looping orbit around the sun. The scientists wanted to recover control of it, but it's not been easy to rekindle an old flame. NPR's Nell Greenfieldboyce reports.
NELL GREENFIELDBOYCE, BYLINE: When a spacecraft called ISEE-3 blasted off in 1978, Jimmy Carter was president and this was the top Billboard hit.
(SOUNDBITE OF SONG, "THREE TIMES A LADY")
LIONEL RICHIE: (Singing) You're once, twice, three times a lady.
GREENFIELDBOYCE: The original plan was for ISEE-3 to hang out between the Earth and the sun to study space weather. But in the 1980s, a NASA mission designer, named Bob Farquhar, figured out a creative way to send it off on a bold, new adventure. It became the first probe to ever visit a commet. Farquhar says some scientists were not amused.
BOB FARQUHAR: They thought - oh, it was in the newspapers, even that we stole their spacecraft. We didn't steal it. We just borrowed it for a while. That's what I tried to tell them.
GREENFIELDBOYCE: It's new flight path would return it to Earth in the far-off year of 2014 and Farquhar has been waiting for the chance to reconnect and put it back to work.
FARQUHAR: It's my baby, yeah.
GREENFIELDBOYCE: But as the date of the rendezvous approached, NASA officials didn't seem that interested. Talking to this agent machine would be a major effort. That's because space communication has changed radically in the last 25 years. So a volunteer group of intrepid space geeks said, let us try. Keith Cowing is one of the group's leaders. He says they had experienced. They'd previously worked with old data tapes to recover moon images taken by orbiters in the 1960s.
KEITH COWING: We'd already done a crazy project with hardware that's not supposed to work with people who were supposed to be dead. And so our common sense had already pretty much disappeared.
GREENFIELDBOYCE: To revive ISEE-3, they solicited donations online and got about $150,000. They unearthed forgotten hardware manuals and found a way to use computer software to speak ISEE-3's obsolete language.
COWING: Our spacecraft does not have a computer. I mean, it's truly accurate to say your toaster is smarter.
GREENFIELDBOYCE: When they finally said hello, the faithful spacecraft answered. And last week, things got even more exciting. They successfully fired its thrusters for the first time since 1986. It really seemed like they're be able to take control of its flight path and send it off to a spot where it could do some useful science. Cowing says this week they sent commands to fire its engines again and again.
COWING: In our first series of burns, we thought went OK. And when we went to the second set, but pretty much nothing happened. And we tried it again and nothing happened.
GREENFIELDBOYCE: The team now thinks that nitrogen tanks needed to pressurize the fuel either aren't working or are empty.
COWING: So in essence, we can't really find engines anymore.
GREENFIELDBOYCE: They may keep trying, but it looks like it's game over. Even Bob Farquhar sees that.
FARQUHAR: I don't know what's the matter but it sounds like it's pretty serious.
GREENFIELDBOYCE: He says without the thrusters there's no way to keep it around. Once it's far enough away that we can't really communicate with it...
FARQUHAR: They should probably turn off all the transmitters this time and not have anything left on like they did before. I think, we should let it have a good death.
GREENFIELDBOYCE: He's always felt his own fate was connected to the spacecraft. Now he says he hopes they're not that connected.
FARQUHAR: But I am getting pretty old also. If you measure the spacecraft's life, it's probably about the same age I am.
GREENFIELDBOYCE: He says his friend should pass close to Earth on August 10. That's when he plans to wave goodbye. Nell Greenfieldboyce, NPR news.
INSKEEP: This is NPR News.
NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.