For nearly a decade, the large probe has been braving the harsh Jovian environment to provide us with mesmerizing up-close views of Jupiter and its moons. But sometimes the gas giant gets the better of it. Recently, the Juno mission unexpectedly went into safe mode during a planned flyby of Jupiter, temporarily shutting down its science instruments.
As NASA recently reported, Juno was making its 71st approach to Jupiter when it switched to safety mode twice on April 4, flying past the gas giant. It is not known what exactly caused Juno to switch to safe mode, but the space agency believes that this could have happened when the spacecraft flew through Jupiter’s radiation belts.
Mission operators resumed data transmission with Juno, and the data showed that the spacecraft first entered safe mode at 5:17 a.m. EDT, which was about an hour earlier than the planned flyby of Jupiter. Juno re-entered safe mode about 45 minutes after perihelion, or close approach, of Jupiter. During safe mode, secondary functions are suspended on the spacecraft. “Yunona turned off scientific instruments but left the communication and power management systems on. The spacecraft restarted its computer and directed its antennas to Earth for communication.
Safe mode is activated when the spacecraft detects an anomaly. Although the team is still waiting to analyze the data to find out exactly what went wrong, preliminary data indicate that Juno was flying through Jupiter’s radiation belts when the safe mode was activated.
Jupiter’s magnetic field is 20,000 times stronger than the Earth’s and is the strongest of all the planets in the solar system. According to the European Space Agency, the planet’s magnetosphere traps charged particles and then accelerates them like a particle accelerator. The largest flows of energetic particles are observed in the donut-shaped belts around Jupiter’s equator, its radiation belts.
Juno boasts a titanium radiation shield that blocks high-energy particles from spacecraft impacts, but sometimes this is not enough. Since arriving at Jupiter in 2016, the spacecraft has entered safe mode four times.
After reconnecting with Juno, the team is working on transferring data collected before and after the safe mode as the spacecraft diagnoses the onboard software, NASA reports.
Juno’s flyby of Jupiter is scheduled for May 7, during which it is expected to make a close approach to Jupiter’s moon Io at a distance of about 55,300 miles (89,000 kilometers). Hopefully, this time the spacecraft will be able to turn on its scientific instruments.
