After an almost five-year journey to the
solar system’s largest planet, NASA's Juno spacecraft successfully entered
Jupiter’s orbit during a 35-minute engine burn. Confirmation that the burn
had completed was received on Earth at 8:53 p.m. PDT (11:53 p.m. EDT) Monday,
July 4.
“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.”
Confirmation of a successful orbit
insertion was received from Juno tracking data monitored at the navigation
facility at NASA's Jet Propulsion Laboratory (JPL) 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.
“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.”
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 the spacecraft’s
rotation rate from 2 to 5 revolutions per minute (RPM) to help stabilize it..
The burn of Juno’s 645-Newton Leros-1b main
engine began on time at 8:18 p.m. PDT (11:18 p.m. EDT), 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. 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.”
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.
“Our official science collection phase
begins in October, but we’ve figured out a way to collect data a lot earlier
than that,” said Bolton. “Which when you’re talking about the single biggest
planetary body in the solar system is a really good thing. There is a lot to
see and do here.”
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 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 also can provide
critical knowledge for understanding the planetary systems being discovered
around other stars.
The Juno spacecraft launched on Aug. 5,
2011 from Cape Canaveral Air Force Station in Florida. JPL manages the Juno
mission for NASA. Juno is part of NASA's New Frontiers Program, managed at
NASA's Marshall Space Flight Center in Huntsville, Alabama, for the agency’s
Science Mission Directorate. Lockheed Martin Space Systems in Denver built
the spacecraft. The California Institute of Technology in Pasadena manages
JPL for NASA.
More information on the Juno mission is
available at:
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