3rd LD Writethru: NASA's Juno spacecraft enters Jupiter's orbit

After a journey of almost five years, the Juno spacecraft entered Jupiter's orbit at about 8:53 p.m. PDT (0353 GMT) on Monday evening, the United States National Aeronautics and Space Administration (NASA) confirmed.

"Engine burn complete and orbit obtained. I'm ready to unlock all your secrets, Jupiter," Juno mission posted on Twitter.

The probe fired its main engine at around 8:18 p.m. PDT (0318 GMT) for Jupiter orbit insertion, or "JOI" as they refer to it in the halls and offices of the Juno team.

After the 35-minute burn of a 645-Newton Leros-1b main engine to slow down the spacecraft, Juno was captured by Jupiter's gravity and slipped into the desired orbit.

Soon after the burn was completed, the probe started to spin down from 5 to 2 Revolutions Per Minute (RPM) and turn back toward the sun so that the sun's rays could once again reach the 18,698 individual solar cells that give Juno energy.

"All rays on me. My solar panels now face the sun. I'm the farthest solar-powered spacecraft from Earth," Juno mission reported via its Twitter feed at about 9:44 p.m. PDT (0444 GMT).

"The spacecraft worked perfectly, which is always nice when you're driving a vehicle with 1.7 billion miles (about 2.74 billion km) on the odometer," Rick Nybakken, Juno project manager from Jet Propulsion Laboratory said.

Orbiting near Jupiter is hazardous. The planet is surrounded by powerful radiation that can fry any spacecraft that comes too near. "It's spinning around so fast. Its gravity is like a giant sling shot, slinging rocks, dust, electrons, whole comets. Anything that gets close to it becomes its weapon," NASA said in a video.

According to NASA, during its mission of exploration, Juno will circle the largest planet in our solar system for 37 times, flying low over the planet's cloud tops, as close as about 4,100 km.

During its stay, the probe will investigate the existence of a solid planetary core, map Jupiter's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere, and observe the planet's auroras.

"Our official science collection phase begins in October, but we've figured out a way to collect data a lot earlier than that," NASA Administrator Charlie Bolden said in a statement.

Juno's name comes from Roman mythology. The mythical god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.

The spacecraft was launched on Aug. 5, 2011, from Cape Canaveral Air Force Station in Florida. Without doubt, the 1.1-billion-dollar mission will provide answers to a lot of questions about Jupiter, and help reveal some secrets about other planets in our solar system, including Earth. Endi