The Juno spacecraft is about to make a close pass at Jupiter (19 Oct) and there was scheduled a engine burn in order to change the spacecraft’s orbit. The burn is not going to happen as scheduled. There is an issue involving the engine being investigated and more time is needed for evaluation. The “burn” was going to change the orbital time from 53 to 14 days and of course it will remain at 53 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 as expected during a command sequence that was initiated yesterday,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. “The valves should have opened in a few seconds, but it took several minutes. We need to better understand this issue before moving forward with a burn of the main engine.”
The good part of the story is now the mission team is going to have ALL the Juno instruments active for the fly-by.
The complete press release is below.