The countdown is on to rebuild communications with a spacecraft before it drifts past this summer. The craft has functional instruments, but NASA has no budget to reactivate the program. It's up to private donors and dedicated volunteers to recapture the abandoned spacecraft.
Launched in the 1970s, repurposed & renamed in 1980s, the ICE/ISEE space explorer still had 12 of 13 functional instruments in the 1990s. Now it's flying past the Earth, beeping out its willingness to chat, but we ripped out the Deep Space Network antenna array in 1999, and no longer have the ability to respond. An international team of engineers is working on a private solution, but needs funds to rebuild the past and send new commands to slide the spacecraft into a new orbit.
In 1978, a triplet of spacecraft were launched as the International Sun-Earth Explorers (ISEE 1, 2, and 3). Their purpose was to investigate Sun-Earth interactions at the very edge of the Earth's magnetic field, examine the solar wind and shock wave at the interface, investigate how the plasma sheets impacted motion and mechanical function, and to continue investigation of cosmic rays and solar flares.
In 1982, one of the spacecraft (ISEE 3) split off to see how solar winds impacted cometary tails. In 1985, it intercepted Comet Giacobini-Zinne, and earned a new name, the International Cometary Explorer (ICE). In 1986, the brave little explorer maneuvered between the sun and Comet Halley, adding to observations made by its satellite-kin Giotto, Planet-A, MS-T5, and VEGA. Finally, it was rerouted to a heliocentric orbit with an an aphelion of 1.03 AU, a perihelion of 0.93 AU and an inclination of 0.1 degree: ever-so-slowly creeping up on the Earth.
By 1987, the ISEE 1 and 2 satellites re-entered the Earth's atmosphere, ending their missions, but ICE/ISEE 3 kept on its stable orbit, ever-so-slowly finding its way home. When ICE/ISEE 3 was going strong in 1991, NASA redirected it yet again, sending it to stare at the sun to record coronal mass ejections, keep observing cosmic rays, and occasionally peek at the Ulysses spacecraft. In 1995, the spacecraft was resigned to a low-duty cycle, sharing costs with Ulysses. In 1997, operations were officially terminated. We stopped talking, but the little spacecraft kept on going.
In 2008, we realized that when we said goodbye, we forgot to tell it we weren't calling back. ICE/ISEE 3 had been faithfully awaiting our next conversation. Shocked and impressed, NASA engineers looked into what it would take to reclaim the satellite and send it off on whole new adventures. By Valentine's Day this year, they reluctantly conceded that since the Deep Space Network transmitters were torn out in 1999, we could listen, understand, but not talk to ICE/ISEE 3. Regretfully, they concluded that on August 10, 2014, the little explorer that lasted far longer than we anticipated, would pass the Earth and continue on its orbit alone with no new instructions.
Imagine the heartbroken wailing and the cries of denial. Insert the demands to find out just how much it would cost to rebuild the antennas in time, and the blank stares when told even $1 was outside of NASA's limited budget. Soon, the inevitable idea emerged: crowdfund our way back into communication with the little spacecraft.
The idea isn't as crazy as it sounds. While the Deep Space Network ripped out the necessary antenna, Morehead State University has an antenna that is successfully picking up ICE/ISEE 3 transmissions. If they can track down the old commands, and built a software emulator for the old hardware, that same dish can theoretically be used to send new commands.
But it's a short timeline: they only have until late May or early June to send ICE/ISEE 3 on a new orbit. If they succeed, the spacecraft will skim past the moon at less than 50 kilometers altitude, and the flyby will boost it along a new, twisting trajectory that will make the most of its limited fuel to continue its mission of collecting all the data it can with its mostly-functional instrument load.
NASA is conceptually supporting the project, happy to watch it succeed as long as ICE/ISEE 3 doesn't ask for money. The volunteers are already archive-diving for the scrapped project notes, calculating a viable trajectory, and scrambling to find private donors to fund the adventure. The funding deadline reflects the short timeline: this happens by May 18th, or it doesn't happen at all. They only need a tiny amount of money to try this longshot chance of recovering our abandoned spacecraft; donate if you can, spread the story if you can't.
It's a big risk, and it may not work, but I, for one, am impressed by the spacecraft that kept on going. Here's to you, ICE/ISEE 3: you lasted far longer than we thought you would, and learned far more than we expected. I dearly hope that we will learn to talk to you again, little explorer.
Image credits: NASA, excepting the projected trajectory, credit ISEE-3 Reboot. Of course xkcd has an alternate plan for the spacecraft. Some of our space explorers from the 1960s were a wee bit less sturdy.