ARCHIVE / 2013 SLINGSHOT TOWARD JUPITER

Today NASA's Juno spacecraft will use Earth's gravity to slingshot toward Jupiter

GUEST BLOG—By NASA.org--Juno is a NASA New Frontiers mission to the planet Jupiter. Juno was launched from Cape Canaveral Air Force Station on August 5, 2011. The spacecraft is to be placed in a polar orbit to study the planet's composition, gravity field, magnetic field, and polar magnetosphere. Juno will also search for clues about how Jupiter formed, including whether the planet has a rocky core, the amount of water present within the deep atmosphere, and how the planet's mass is distributed. It will also study Jupiter's deep winds, which can reach speeds of 618 kilometers per hour (384 mph).

The spacecraft's name comes from Greco-Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, but his wife, the goddess Juno, was able to peer through the clouds and see Jupiter's true nature. Juno requires a five-year cruise to Jupiter, arriving around July 4, 2016. The spacecraft will travel over a total distance of roughly 1.74 billion miles). The spacecraft will orbit Jupiter 33 times during one Earth year.

Juno's trajectory will use a gravity assist speed boost from Earth, accomplished through an Earth flyby two years (October 9, 2013) after its August 5, 2011 launch.

Today’s Earth flyby will boost Juno’s velocity by 16,330 mph placing the spacecraft on its final path for Jupiter.  Today marks the closest approach to Earth by Juno when Juno is at an altitude of about 348 miles.

In August of 2016, the spacecraft will perform an orbit insertion burn to slow the spacecraft enough to allow capture into an 11-day polar orbit. Once Juno enters into its orbit, infrared and microwave instruments will begin to measure the thermal radiation emanating from deep within Jupiter's atmosphere. These observations will complement previous studies of the planet's composition by assessing the abundance and distribution of water, and therefore oxygen.

While filling missing pieces of the puzzle of Jupiter's composition, these data will also provide insight into the planet's origins. Juno will also investigate the convection that drives general circulation patterns in Jupiter's atmosphere. Meanwhile, other instruments aboard Juno will gather data about the planet's gravitational field and polar magnetosphere.

The Juno mission is set to conclude in October 2017, after completing 33 orbits around Jupiter, when the probe will be de-orbited to crash into Jupiter so as to avoid any possibility of it impacting its moons.

Scott Bolton of the Southwest Research Institute in San Antonio, Texas is the principal investigator and is responsible for all aspects of the mission. The Jet Propulsion Laboratory in California manages the mission and Lockheed Martin Corporation is responsible for the spacecraft development and construction. The mission is being carried out with the participation of several institutional partners. Co-investigators include Toby Owen of the University of Hawaii, Andy Ingersol of California Institute of Technology, Fran Bagenal of the University of Colorado at Boulder, and Candy Hansen of the Planetary Science Institute. Jack Connerney of the Goddard Space Flight Center served as instrument lead.