On Friday, NASA announced that it Juno spacecraft would remain in its current 53-day orbit of Jupiter for the duration of its mission. The decision is a new setback for the spacecraft, which was scheduled to shift to a shorter, 14 day orbital schedule.
This isn’s the first time that Juno has run into issues orbiting Jupiter. In October, NASA delayed an orbit around the planet due to a pair of helium check valves not working properly. While the spacecraft has since completed two additional orbits — the latest was on February 2nd — the mission’s planners were concerned that “another main engine burn could result in a less-than-desirable orbit,” explained Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory.
Juno’s 53-day orbit is highly elliptical, taking the spacecraft within 2,600 miles of the atmosphere to five million miles away, which helps the spacecraft minimize its exposure to the planet’s radiation belts. In a shorter orbit, the spacecraft would have completed 33 orbits. The decision to keep Juno in its present orbit will help reduce the chances of something going wrong, but it also means that Juno will be able to conduct fewer orbits. The next flyby is scheduled to take place on March 27th.
Despite the change, NASA noted that it will be able to do some additional work that wasn’t originally planned, such as exploring the planet’s magnetosphere. The decision to keep Juno in its current orbit will also limit its exposure to Jupiter’s radiation. “This is significant,” Scott Bolton, Juno principal investigator from Southwest Research Institute in San Antonio explained, “because radiation has been the main life-limiting factor for Juno.”
Currently, Juno is scheduled to fly through July 2018 for 12 additional orbits, and mission planners will evaluate extending its life. Once the mission is over, the spacecraft will be de-orbited and will burn up in Jupiter’s atmosphere to avoid any potential contamination of the Jovian moons.