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NASA Readies for Juno Spacecraft’s Jupiter Approach

NASA’s solar-powered Juno is expected to begin orbiting the planet Jupiter on July 4, 2016, nearly five years after the spacecraft’s launch. (NASA courtesy photo)

On a day when America commemorates its independence with July 4 fireworks displays, the U.S. space agency anticipates a celestial event that could prove hugely illuminating about the planet Jupiter and the beginnings of our solar system.

NASA’s solar-powered Juno spacecraft, hurtling through space for five years and nearly 2 billion miles, has been programed for what the agency hopes is
"a suspenseful orbit insertion maneuver" beginning at 11:18 p.m. Monday EDT (3:18 a.m. Tuesday GMT). If all goes according to plan, a 35-minute "engine burn" will slow the spacecraft just enough for it to be pulled into Jupiter’s orbit.

From there, Juno is expected to circle the planet 37 times over 20 months, sometimes as close as 4,800 kilometers (3,000 miles) from the planet’s surface,

Orbiting over Jupiter’s poles could yield revelations "about the planet’s core, composition and magnetic fields," NASA said on its website.

Complicated task

"It is not easy for NASA to get the answers that humanity seeks," Scott Bolton, the mission’s lead scientist, said at a news conference Monday at NASA’s Jet Propulsion Lab at the California Institute of Technology in Pasadena. "… Juno’s searching for hints about our beginnings – how did the solar system get started?"

Jupiter is composed of helium and hydrogen gases, unlike the rocky planet Earth. Delving into its composition may offer lessons about its development and that of the solar system.

But first, the spacecraft must navigate a magnetic field, extreme radiation belts and a ring of debris around the planet, Bolton and several other mission scientists said at the briefing.

"If any dust is in our way, it will knock a hole right through the coating," Bolton said.

It’s "the scariest part of the scariest place," said Heidi Becker, a space physicist at the lab. With both spacecraft and debris moving at high velocity, one errant particle will "fry your brain if you don’t do anything about it."

'Built like a tank'

The brain of the propeller-shaped spacecraft, which was crafted by the Lockheed Martin aeronautics firm, is its computer. It's encased in titanium walls nearly a half-inch thick, Becker said.

"We are built like an armored tank," Bolton said earlier.

A space physicist with the Southwest Research Institute in San Antonio, Texas, Bolton said his favorite holiday is July 4, Independence Day, and this one is most special because of the momentous event.

NASA is tracking Juno’s Jupiter rendezvous with a countdown and live video streaming at and

The mission carries an estimated $1.1 billion price tag. It’s expected to end with the spacecraft making a kamikaze dive into Jupiter’s atmosphere, where it will burn up instead of adding debris to space.

The solar-powered Juno spacecraft, built by Lockheed Martin, was designed for harsh environments.
The solar-powered Juno spacecraft, built by Lockheed Martin, was designed for harsh environments.