Hello Jupiter! NASA's Juno spacecraft arrives at giant planet

NASA’s solar-powered Juno spacecraft successfully entered Jupiter’s orbit on Tuesday after a five-year journey from Earth, in a giant step to understand the origin and evolution of the king of planets and the solar system.

As America celebrated its Independence Day, mission controllers at NASA’s Jet Propulsion Laboratory erupted in cheers when the $1.1 billion (Rs 7,414 crore) 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.

Pre-planned 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 to help stabilise it.

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

Soon after the burn was completed, Juno turned so that the Sun’s rays could once again reach the 18,698 individual solar cells that give Juno its energy.

“The spacecraft worked perfectly, which is always nice when you’re driving a vehicle with 1.7 billion miles on the odometer,” said Rick Nybakken, Juno project manager from JPL.

“Jupiter orbit insertion was a big step and the most challenging remaining in our mission plan, but there are others that have to occur before we can give the science team the mission they are looking for,” said Nybakken.

Over the next few months, Juno’s mission and science teams will perform final testing on the spacecraft’s subsystems, final calibration of science instruments and some science collection.

Juno’s name comes from Greek and 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 unveil Jupiter’s true nature.

Mission in numbers

>> 2.8 billion kilometres

The total distance travelled from launch to arrival.

>> 5,000 kilometres

That’s how close Juno will fly to Jupiter’s cloud tops.

>> 48 minutes, 19 seconds

The time it takes for radio signals from Jupiter to reach Earth.

>> 20 months

The time the mission will last. Eventually, Juno will succumb to the intense radiation and will be commanded to plunge into Jupiter’ atmosphere to avoid any collision with the planet’s moons.

>> Nine

Juno carries a suite of nine instruments to explore Jupiter from its interior to its atmosphere. It will map Jupiter's gravity and magnetic fields and track how much water is in the atmosphere. Its colour camera dubbed JunoCam will snap close-ups of Jupiter’s swirling clouds, polar regions and shimmering southern and northern lights.