NASA's Juno mission managers have postponed the burn of the main rocket, which was initially scheduled for Oct. 19. The burn, dubbed period reduction maneuver, is aimed at reducing Juno's orbital period from 53.4 days to only 14.
The team designing the mission has decided to delay the period reduction maneuver in order to analyze the performance of a set of valves that are part of Juno's fuel pressurization system. They also limited the use of science instruments for Juno's burn. However, since the period reduction maneuver is delayed, the entire suite of instruments will gather as much information as possible in the upcoming flyby.
Approximately two months ago, the spacecraft settled into Jupiter's orbit, after three years of wandering in space. As its primary Leros 1b engine having issues and malfunctions, the helium check valves showing problems will have to be carefully inspected and fixed within the shortest time possible.
"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. The valves should have opened in a few seconds, but it took several minutes," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, California.
The PRM will be delayed at least one orbit, which makes Dec. 11 the upcoming chance for the mission to be completed. The reason why it's efficient to schedule a PRM during that time is that the spacecraft is closest to the planet as possible.
The decision will have an impact on the entire upcoming calendar related to this mission. Aside from fixing the current issues, the team will have to delay other events on the analysis of the data gathered by the probe, as well.
While coming up with a quick fix is not something easy to do for the team working on the project, all Juno should do is manage to go through the PRM successfully. From there on, it will be possible for the probe to use the smaller thrusters for fine-grain movement, replacing the problematic engine. The close-up images of the gas giant would, eventually, give enough data to support future systematic research and provide an in-depth understanding of Jupiter.
Juno's launch took place on Aug. 5, 2011 in Cape Canaveral, Florida, arriving at Jupiter during the U.S. Independence day 2016. One of the most interesting features of the probe is its camera. JunoCam snapped closeups of Jupiter during its time on the orbit, accompanied by high resolution images of the gas giant's atmosphere. Other images that grabbed attention were the planet's northern and southern poles.
In August, Steve Levin, a Juno project scientist, anticipated that issues could appear because of the probe's position so close to the planet, but for the team, ensuring the quality of data gathered justifies the additional time devoted to the project.