Juno arrives at Jupiter: ‘It’s the end of the voyage, but it’s the beginning of the science’

The Juno team celebrates at NASA's Jet Propulsion Laboratory.

After completing its nearly five-year journey through the solar system and positioning itself into orbit around Jupiter, NASA’s Juno spacecraft is set to boot up its scientific instruments Wednesday night and begin its close-up study of the giant and mysterious planet.

Engineers had turned off Juno’s instruments in preparation for the spacecraft’s final approach Monday night to keep the tricky maneuver as simple as possible. But with that challenge behind them, members of the mission team quickly shifted their focus to the future.

“What I’m really looking forward to is getting up close and personal with Jupiter,” said Steven Levin, Juno’s project scientist at the Jet Propulsion Laboratory.

Juno completed its more than 1.7-billion-mile journey on Monday night and slipped into Jupiter’s orbit at 8:53 p.m. PDT, a mere 1-second deviation from its intended schedule.


Upon receiving the tone that signaled Juno’s entry into orbit, the mission control room at the Jet Propulsion Laboratory erupted into cheers, wild applause, high-fives and hugs.

“Juno, welcome to Jupiter,” came the announcement over the intercom.

Rick Nybakken, Juno’s project manager, celebrated the success by tearing up a copy of the space agency’s contingency communications procedure — the plan for if the mission failed. They don’t need that.

“Tonight, through tones, Juno sang to us, and it was a song of perfection,” Nybakken said at a briefing Monday night.

The Juno mission seeks to answer profound questions about Jupiter that eluded the grasp of earlier missions. By studying its atmosphere, magnetic field, composition and internal structure, the scientists hope to learn what lies deep beneath the surface layers of this many-banded, red-eyed gas giant.

The answers to some of its most pressing mysteries — including whether Jupiter has a rocky core, and how much water lies within it — could help scientists understand how our solar system, including Earth, came to be.

“It’s the end of the voyage, but it’s the beginning of the science,” said Michael Watkins, who took over as director of JPL on Friday.

As Juno made its final approach, engineers at the lab in La Cañada Flintridge waited quietly for the tones that signaled the spacecraft’s progress.

One of those tones confirmed that Juno began a 35-minute main engine burn at 8:18 p.m. This crucial braking maneuver allowed Jupiter to yank the craft out of its orbit around the sun and pull it into its own embrace.

When it was over, the craft reoriented itself so that its three solar panels were facing the sun.

Jupiter is so far away that it takes 48 minutes for messages to travel between Earth and Juno. That meant the craft had to do it alone, relying on preprogrammed instructions.

As it closed in on Jupiter, the craft’s JunoCam took a series of pictures of the planet and its four largest moons over 17 days. By weaving them together into a time-lapse movie, scientists got their first direct view of planetary motion in action.

“In all of history we’ve never really been able to see the motion of any heavenly body against another,” said Scott Bolton, the principal investigator for the Juno mission who is based at the Southwest Research Institute. He called the circular dance of the moons around the planet an example of “true harmony in nature.”

Juno is now in a highly elliptical 53-day orbit around Jupiter, which means it won’t make a close pass over the planet’s surface for several weeks.

And even though the instruments are coming back online Wednesday night, they won’t get a close-up view until Aug. 27, Levin said in an interview Tuesday.

“The science instruments will start collecting data, but we’re moving away from Jupiter,” he said.

Follow @aminawrite on Twitter for more science news and “like” Los Angeles Times Science & Health on Facebook.


NASA’s dangerous Juno mission: Unravel Jupiter’s secrets and solve the mysteries of life

On Jupiter, never-ending auroras seem to be ‘throwing a fireworks party’ for approaching NASA craft

These remarkable frigate birds can fly without landing for months at a time


5:47 p.m.: The story was updated with new information about plans to restart Juno’s scientific instruments.

The story was originally published at 1:36 a.m.