CAPE CANAVERAL, Florida - After launching from Cape Canaveral Air Force Station in Florida nearly five years ago, NASA's Juno spacecraft finally reached Jupiter on the Fourth of July, 2016.
While Americans were busy celebrating Independence Day with fireworks, the Juno probe fired its main engine to place it into a polar orbit around the gas giant. The 35-minute burn of the spacecraft's 645-Newton Leros-1b main engine began on time at 11:18 p.m. Eastern Daylight Time, decreasing the spacecraft’s velocity by 1,212 miles per hour (542 meters per second) and allowing Juno to be captured in orbit around Jupiter. Confirmation that the burn had completed was received on Earth at 11:53 p.m. EDT.
“Independence Day always is something to celebrate, but today we can add to America’s birthday another reason to cheer -- Juno is at Jupiter,” said NASA administrator Charlie Bolden. “And 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.”
Soon after the burn was completed, Juno turned so that the sun’s rays could once again reach the spacecraft's 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,” said 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.”
As the largest planet orbiting the sun, Jupiter has had a profound influence on the solar system. But its origin remains a profound mystery. To learn how Jupiter formed and how it has evolved, 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 explore the swirling clouds that form Jupiter’s colorful, trademark atmosphere.
The mission also help scientists understand how gas giant planets form and the role these titans played in putting together the rest of the solar system.
Photo and video: Artist animation Credit: NASA/JPL/SwRI