A model of the Juno spacecraft is seen at a news briefing, held before Juno enters orbit around Jupiter, on Thursday, June 30: NASA

By Glynn Wilson –

Scientists have confirmed that Juno, a craft the size of a football field launched to explore some key secrets of space, successfully entered the volatile atmosphere in an orbit around Jupiter Monday night about the time most Fourth of July fireworks shows in the United States were climaxing.

After a five-year journey to the solar system’s largest planet, NASA recieved confirmation that a 35-minute burn had completed and the orbit began at 11:53 p.m. Eastern Standard Time. Cheers broke out at the mission’s control centers in California and Colorado.

“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 said in the announcement. “And what is more American than a NASA mission going boldly where no spacecraft has gone before?”

Confirmation of a successful orbit insertion was received from Juno tracking data monitored at the navigation facility at NASA’s Jet Propulsion Laboratory in Pasadena, California, as well as at the Lockheed Martin Juno operations center in Littleton, Colorado. The telemetry and tracking data were received by NASA’s Deep Space Network antennas in Goldstone, California, and Canberra, Australia.

“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,” Bolden said.

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 Fourth 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.”

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. “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.”

Juno’s principal goal is to understand the origin and evolution of Jupiter. 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 take a giant step forward in scientists understanding of how giant planets form and the role they play in putting together the rest of the solar system. As a primary example of a giant planet, Jupiter also can provide critical knowledge for understanding the planetary systems being discovered around other stars.

“Our official science collection phase begins in October, but we’ve figured out a way to collect data a lot earlier than that,” Bolton said. “When you’re talking about the single biggest planetary body in the solar system (that’s) a really good thing. There is a lot to see and do here.”

The Juno spacecraft, part of NASA’s New Frontiers Program managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, launched on Aug. 5, 2011 from Cape Canaveral Air Force Station in Florida. Lockheed Martin Space Systems in Denver built the craft. The California Institute of Technology in Pasadena manages the program for NASA.

More information on the Juno mission is available at this link.