Even though they might not be able to capture the spacecraft, Mr. Cowing said they were devising an alternative in which ISEE-3 would collect scientific data and send it back to Earth. "There's a Plan B," he said. "We're going to listen to the spacecraft as long as it talks."
On Wednesday, members of the ISEE-3 Reboot Project spent two hours attempting to diagnose and repair the problem by "jiggling" fuel valves on and off and instructing the 36-year-old craft to fire several of its 12 thrusters. When these attempts failed to work, engineers concluded that the satellite's fuel system had lost critical pressure. "We have exhaustively tested the propulsion system with no good results," Dennis Wingo, chief executive of Skycorp Inc., and leader of the privately run project, said on his Twitter account.
The ISEE-3 Reboot Project efforts were funded with $160,000 raised on the crowd-funding website RocketHub.com. Another fundraising drive likely would have been required for the citizen science campaign Cowing and Wingo were planning. "We did stuff that was widely seen as impossible, improbable, and impractical," said Cowing. "You need to focus on the absurd things that are possible."