NASA’s daring Juno spacecraft must fly into the heart of Jupiter’s deadly radiation belts to complete its mission. So far, so good. On Saturday morning, the spacecraft made its first close approach to Jupiter, flying to within 4,200 km of the solar system giant. That is less than the distance from New York to Los Angeles.
The spacecraft sped past Jupiter at 208,000 km/h relative to the planet, and mission managers declared Juno to be in good health. “Early post-flyby telemetry indicates that everything worked as planned and that Juno is firing on all cylinders,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. Saturday’s flyby at 9:44 a.m. ET marked the first time Juno had activated its full complement of nine science instruments and pointed it at Jupiter.
Mission managers said the early return of the data was promising, but warned it would take several more days to download all the information collected by the spacecraft and begin assessing what it means. While photography isn’t the main objective of the mission, NASA plans to release photos taken during the flyby over the next week. The images are expected to include the highest resolution ever of Jupiter’s atmosphere, and the first good images of both poles of the gas giant.
NASA hopes to get 36 orbits around Juno in the next 20 months before radiation slowly breaks down its electronics and propulsion system. While a 1cm-thick titanium wall provides some protection for the spacecraft’s electronics, some of the nine instruments may begin to fail after as little as eight or 10 revolutions.
During its lifetime, Juno will probe Jupiter’s interior using two magnetometers, which will help scientists map the planet’s magnetic field. They hope to understand exactly how that intense magnetic field is generated, which may be related to how hydrogen behaves at the very high pressure in the planet’s center. Other instruments on board will measure Jupiter’s gravitational field, cloud structure and the amount of water in Jupiter’s atmosphere.