Washington: Touted as a perfect gift as the US celebrated its Independence Day on July 4, cheers erupted at NASA’s California-based Jet Propulsion Laboratory as its solar-powered Juno spacecraft ended an almost five-year journey to enter the orbit around Jupiter.
“Independence Day always is something to celebrate but today, we can add to America’s birthday another reason to cheer — Juno is at Jupiter,” NASA administrator Charlie Bolden told a jubilant team of scientists.
At 8.48 am on Tuesday (India time), Juno fired its main engine to begin a 35-minute burn to get into orbit around Jupiter. The burn time was within one second of the predicted time, placing it in the orbit it needed.
“What is more American than a NASA mission going boldly where no spacecraft has gone before? 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,” he added.
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.
“This is the one time I don’t mind being stuck in a windowless room on the night of the 4th of July,” noted Scott Bolton, principal investigator of Juno from Southwest Research Institute in San Antonio.
“The mission team did great. The spacecraft did great. We are looking great. It’s a great day,” he added.
“Success! Engine burn complete. #Juno is now orbiting #Jupiter, poised to unlock the planet’s secrets,” NASA tweeted.
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.
“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.
Once in Jupiter’s orbit, the 1,600 kg spacecraft will circle the Jovian world 37 times during 20 months, skimming to within 5,000 km above the cloud tops.
“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,” Nybakken pointed out.
With its suite of nine science instruments, Juno 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.
The mission also will let us take a giant 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.
As our primary example of a giant planet, Jupiter can also provide critical knowledge for understanding the planetary systems being discovered around other stars.
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 reveal Jupiter’s true nature.
The four largest moons of Jupiter are named the Galilean moons because they were discovered by Galileo Galilei in 1609.