Juno is Back! Jupiter Probe Exits ‘Safe Mode,’ Prepares for Next Flyby

NASA's Juno spacecraft has finally bounced back after experiencing a glitch last week. Juno went into "safe mode" on Oct. 19 as it made its second close flyby of Jupiter after experiencing technical troubles. But mission controllers have successfully commanded the spacecraft to exit safe mode on Oct. 24 and the probe now appears to be working well.

"Juno exited safe mode as expected, is healthy and is responding to all our commands," Rick Nybakken, Juno project manager from NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement. "We anticipate we will be turning on the instruments in early November to get ready for our December flyby."

The Jupiter probe went into safe mode after a software performance monitor caused the spacecraft's onboard computer to reboot. The mission team is still investigating the cause of the reboot and is assessing two main engine check valves, NASA said.

The spacecraft also experienced an engine trouble earlier while orbiting Jupiter, which was detected during a routine engine check. NASA officials found that two helium check valves, which were crucial to the spacecraft's main engine, did not operate as expected, delaying the engine burn.

In preparation for the December flyby, Juno performed an orbital trim maneuver on Tuesday, firing its smaller thrusters for over 30 minutes to change its orbital velocity by about 5.8 mph. The flyby is scheduled on Dec. 1, with the time of closest approach to the giant planet happening at 12:03 pm EDT.

"We are all excited and eagerly anticipating this next pass close to Jupiter," Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio, said in the same statement. "The science collected so far has been truly amazing."

Juno launched in August 2011 from Cape Canaveral, Florida, and arrived at the gas giant on July 4, 2016. The solar-powered probe is equipped with nine science instruments that are used to study Jupiter's origins, structure, atmosphere, and magnetosphere. Data are gathered during the spacecraft's close flyby's, where it soars low over the planet's cloud tops, about 4,100 kilometers (2,600 miles) close.