NASA's Juno spacecraft enters Jupiter's orbit

As America celebrated its Independence Day, mission controllers at NASA's Jet Propulsion Laboratory (JPL) erupted in cheers when the USD 1.1 billion Juno spacecraft sent home the news of successfully executing a 35-minute engine burn that put the probe into the planned orbit around Jupiter.

With its suite of nine science instruments, Juno will study 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 auroras on our solar system's largest planet.

The mission also will let us take a big step forward in our understanding of how giant planets form and the role these titans played in putting together the rest of the solar system, NASA said.

As our primary example of a giant planet, Jupiter also can provide critical knowledge for understanding the planetary systems being discovered around other stars.

The Juno spacecraft launched on August 5, 2011 from Cape Canaveral Air Force Station in Florida.

"With Juno, we will investigate the unknowns of Jupiter's massive radiation belts to delve deep into not only the planet's interior, but into how Jupiter was born and how our entire solar system evolved," said NASA administrator Charlie Bolden.

Confirmation of a successful orbit insertion was received from Juno tracking data monitored at the navigation facility at JPL in California, as well as at the Lockheed Martin Juno operations centre in Colorado.

The telemetry and tracking data were received by NASA's Deep Space Network antennas in the US and Australia.

Preplanned events leading up to the orbital insertion engine burn included changing the spacecraft's attitude to point the main engine in the desired direction and then increasing the spacecraft's rotation rate from 2 to 5 revolutions per minute (RPM) to help stabilise it.

The burn of Juno's main engine began at 8:48 am IST, decreasing the spacecraft's velocity by 542 meters per second and allowing Juno to be captured in orbit around Jupiter.