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Juno spacecraft nears July 4 rendezvous with Jupiter

Artist's depiction of NASA's Juno spacecraft approaching Jupiter. Image Credit: JPL / NASA posted on SpaceFlight Insider

Artist’s depiction of NASA’s Juno spacecraft approaching Jupiter. (Click to enlarge) Image Credit: JPL / NASA

NASA’s Juno spacecraft is poised to arrive and enter into orbit around Jupiter on July 4, 2016, completing a nearly six-year-long voyage. Juno is scheduled to orbit the largest planet in the Solar System for 20 months as it studies Jupiter’s atmosphere, interior, and magnetic fields.  

The Juno mission is managed by NASA’s Jet Propulsion Laboratory located in Pasadena, California, and is part of the space agency’s New Frontiers Program, which also includes the New Horizons spacecraft and the upcoming OSIRIS-REx mission.

Lockheed Martin built Juno for NASA, and several of the company’s engineers partner with JPL and the various science instrument teams to operate the robotic spacecraft.

Mission operations for the Juno spacecraft are controlled from Lockheed Martin’s Mission Support Area (MSA) located near Denver, Colorado. In addition to Juno, mission operations engineers at MSA are flying three spacecraft orbiting Mars – Mars Odyssey, Mars Reconnaissance Orbiter, and MAVEN – as well as the Spitzer Space Telescope which is in a heliocentric orbit near Earth.

Since 1989, Lockheed Martin has worked on NASA teams to operate 13 planetary spacecraft, including missions like Magellan and Mars Global Surveyor.

“The science that comes back from these missions is the reason I do this,” said MSA manager Kenny Starnes. “These missions have rewritten so many science books from their discoveries, and it’s so exciting knowing your team played a part in getting those results.”

From left to right: Kenny Starnes, Kristen Francis, Alexandra Hilbert, Bryce Strauss and Will Santiago. Image Credit: NASA/JPL-Caltech

From left to right: Kenny Starnes, Kristen Francis, Alexandra Hilbert, Bryce Strauss, and Will Santiago. Image Credit: NASA / JPL-Caltech

Juno is the first solar-powered spacecraft to be sent to Jupiter, and it holds the record for the farthest spacecraft from the Sun to operate on solar power. When it reaches Jupiter, the spacecraft will get only about four percent of the sunlight it received near Earth.

The spacecraft has three 30-foot long solar arrays that always face the Sun, except during the Jupiter Orbit Insertion on July 4, which will slow the spacecraft and capture it in orbit around the planet.

The many components and scientific instruments on Juno have specific temperature preferences to function optimally. The spacecraft has electric heaters to warm components and vents which can be opened to cool them.

“The spacecraft itself has software control much like your thermostat at home,” said thermal engineer Will Santiago. “There’s a wide range of required temperatures on the spacecraft – avionics want to be running around room temperature, but there are science instruments that are sensitive to heat and need to remain quite cold.”

On May 6, 2016, Juno was approximately 450 million miles (745 million kilometers) from Earth. The one-way radio signal time between Juno and Earth is approximately 40 minutes. The spacecraft is in excellent health and is operating nominally.

Juno launched from Cape Canaveral Air Station’s Space Launch Complex 41 in Florida on August 5, 2011, atop a United Launch Alliance (ULA) Atlas V 551 variant booster.

Juno‘s trajectory used a 2013 flyby of Earth to gain a gravity-assisted speed boost. Once the orbital insertion burn is made, the spacecraft will settle into a 14-day polar orbit above Jupiter. The Juno mission is set to conclude in February of 2018, after completing 37 orbits. The spacecraft will be de-orbited and will then burn up in Jupiter’s upper atmosphere, in order to avoid any possibility of impact and contamination on one of the Jovian moons.

NASA issued a statement on May 27, 2016, noting how the spacecraft had crossed the Sun/Jupiter gravitational boundary.

“Today the gravitational influence of Jupiter is neck and neck with that of the Sun,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. “As of tomorrow, and for the rest of the mission, we project Jupiter’s gravity will dominate as the trajectory-perturbing effects by other celestial bodies are reduced to insignificant roles.”

Video courtesy of NASA/JPL-Caltech



Jim Sharkey is a lab assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of Skylab and Shuttle astronaut Owen K. Garriott. As a young Star Trek fan he participated in the letter-writing campaign which resulted in the space shuttle prototype being named Enterprise. While his academic studies have ranged from psychology and archaeology to biology, he has never lost his passion for space exploration. Jim began blogging about science, science fiction and futurism in 2004. Jim resides in the San Francisco Bay area and has attended NASA Socials for the Mars Science Laboratory Curiosity rover landing and the NASA LADEE lunar orbiter launch.

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