Citizen Scientists Revive ISEE-3, But Pressurant Shortfall Halts Major Return
In 2014 a crowd-funded, private team used software-defined radio and global observatories to re-activate NASA’s ISEE-3 probe, firing its spin thrusters and re-establishing two-way communication after decades of dormancy; however, a planned large burn to retarget the craft failed because the nitrogen pressurant had likely depleted, leaving the mothballed probe in heliocentric orbit and preserving data from its revived operations rather than achieving the intended Earth–Sun observation path.