Juno Jupiter Probe's Final Engine Burn Delayed by Glitch

NASA's Juno Jupiter probe won't be settling into its final orbit around the giant planet this week after all. Juno was scheduled to fire its main engine for the final time during the probe's close Jupiter flyby on Wednesday (Oct. 19), in a maneuver that would reduce the time it takes the spacecraft to circle the gas giant from 53 Earth days down to 14 days. "Telemetry indicates that two helium check valves that play an important role in the firing of the spacecraft's main engine did not operate