NASA’s Juno Spacecraft Enters Jupiter’s Orbit After 5-Year Journey

NASA's Juno Spacecraft

NASA’s robotic Juno probe began circling the solar system’s largest planet late Monday, ending a nearly five-year journey through deep space and becoming the first spacecraft to enter Jupiter orbit since NASA’s Galileo mission did so in 1995.

The milestone came late Monday, as Juno fired its main engine in a crucial 35-minute burn that slowed the probe down enough to be captured by Jupiter’s powerful gravity. That burn started at 11:18 p.m. EDT and ended on schedule at 11:53 p.m.

In the hours leading up to the engine burn, that same gravity had accelerated Juno to an estimated 165,000 mph relative to Earth — faster than any human-made object has ever traveled, mission team members have said.

Tonight’s orbit-insertion burn, which Juno performed on autopilot, was a make-or-break maneuver: If anything had gone seriously wrong, Juno would have gone sailing right past Jupiter, and the science goals of the $1.1 billion mission — which including mapping the planet’s gravitational and magnetic fields and characterizing its composition and interior structure — would have gone unaccomplished.

So the jubilation that erupted at Juno mission control here at NASA’s Jet Propulsion Laboratory (JPL) — shouts of joy, high-fiving and hugging among team members — made a lot of sense.

“Welcome to Jupiter!” a mission commentator announced just after the burn ended, eliciting a second round of cheers and then, a few moments later, a standing ovation.