Why NASA's Juno entering Jupiter's orbit is momentous

"What is more American than a NASA mission going boldly where no spacecraft has gone before?" exclaimed NASA administrator Charlie Bolden after successful injection of spacecraft Juno into the orbit of Jupiter on the night of July 4, when America was celebrating its independence day.

The primary goal of the orbiter is to help understand Jupiter's formation and evolution. It will investigate the planet's origins, interior structure, deep atmosphere and magnetosphere.

All this knowledge is supposed to tell us more about how Jupiter was formed and eventually how the solar system evolved. Juno was launched in August 2011, taking nearly five years to reach Jupiter which is the largest planet in the solar system. Juno's mission is scientific, but the space agency has clearly made a larger statement.

"Independence Day always is something to celebrate, but today we can add to America's birthday another reason to cheer -- Juno is at Jupiter," Bolden added.

Though it is unclear if the final orbit injection maneuvers of the spacecraft were timed to coincide with July 4 celebrations. 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 its rotation rate to help stabilize it.

The orbital injection was most challenging part of the mission.

It is the second time NASA has reached out to Jupiter. Its first mission, Galileo, was launched in 1989 and reached an orbit around Jupiter in 1995. It provided valuable data about Jupiter and its moons.

However, Juno has more powerful payloads and will orbit over poles of Jupiter, unlike Galileo. The spacecraft will see below Jupiter's dense cover of clouds. This is why the mission has been named after the Roman goddess who was Jupiter's wife and who could also see through clouds.

Incidentally, Juno has carried three figurines - that of astronomer Galileo, Roman god Jupiter and goddess Juno - supplied by toy company Lego, to attract children to space science.

Over the next few months, scientists will perform final testing on the spacecraft's subsystems, final calibration of instruments and data collection could start in October. Scientific instruments are designed to collect data on the planet's solid planetary core, its intense magnetic field, and also measure amount of water and ammonia in its deep atmosphere.

The American space agency used the Jupiter mission to engage with public in unique ways via social media. It created an app called "Eyes on the Solar System" which used simulated data from the Juno flight team to let people experience a ride onboard the spacecraft. In this interactive visualization, people could ride along with the Juno spacecraft in real-time at any time during the entire mission. Thus people could learn about science of the mission.

Juno's Twitter handle was used to provide live updates as well as to answer questions about different aspects of the mission.

Of late, Indian Space Research Organization (ISRO) has begun engaging people via social media about its missions, but this engagement needs to be deepened and widened.

The distances and speeds involved in the mission are mind boggling. The distance between the earth and Jupiter distance at time of launch was 716 million kilometers, and it took 39 minutes 50 seconds for light to cover this distance.

In all, the spacecraft has traveled 2.8 billion kilometres during its long, looping journey.

If Juno was to fly at the speed of a commercial plan, it would have taken 342 years to complete the journey.