Notes from a panel at Capricon 44, Chicago, Feb. 2, 2024. Any mistakes are mine. The panelists are not responsible for any errors here.

Bill Higgins, Randall Roman, Henry Spencer

Our panelists discuss the flyby probes of the 1970s: the Pioneers, Voyagers, Mariners, etc. Where are they now and are we still getting anything useful from them?

• Spacecraft generally either fail early in the mission, or last for a long time.
• RTGs are the limiting on-board factor. Not so much because of the Plutonium-238 fuel, which has a half-life of 87.7 years, but because the semiconductors deteriorate due to radiation damage.
• There is a cost to keeping the ground stations open when a spacecraft greatly exceeds its designed life. NASA liked ending the Cassini mission with a crash into Saturn so this would not become an issue.
• The life of a spacecraft can be extended by powering down instruments that are no longer needed. This was done with the Voyagers after their last planetary encounters. They are now the “Voyage Interstellar Mission.”