“A year from now, New Horizons will join four other unmanned spacecraft speeding out of our solar system: Pioneer 10, Pioneer 11, Voyager 1 and Voyager 2.
“The Pioneers (are) now dead,” said Randii Wessen, a spokesman for NASA and an astronautical engineer who works on future mission concepts at NASA’s Jet Propulsion Laboratory at the California Institute of Technology. The Pioneer 10 and Pioneer 11 explored Jupiter and Saturn in the 1970s and stopped sending information back to NASA in 2003 and 1995, respectively.
Voyagers 1 and 2, which also were launched in the 1970s, are still transmitting data back to NASA. According to Wessen, NASA gets 16 hours of information a day from the Voyagers, but they’re losing fuel and power.
“We’re slowly turning off things to reduce the electrical demand so the power we do have is used for the critical systems,” Wessen said. “But what are you going to run out of first? We’re saying 2020-2025 is when we’re going to lose them.””
Read more at: phys.org.