NASA’s Juno Spacecraft Makes Jupiter Orbit After Five Years Traveling Across the Solar System

Juno team still celebrating confirmation of successful insertion into Jupiter orbit

This computer-generated image depicts NASA’s Juno spacecraft firing its Leros-1b main engine. Credits: NASA/JPL

Space news (Space missions to Jupiter: NASA; Juno makes orbit around mighty Jupiter) – 370 million miles (596 million kilometers) from Earth, traveling at around 11 miles per second (17 kilometers per second) relative to the Sol, or 29 miles/second (46 kilometers/s) relative to Earth – 

This artist's rendering shows NASA's Juno spacecraft above the north pole of Jupiter. Credits: NASA/JPL
This artist’s rendering shows NASA’s Juno spacecraft above the north pole of Jupiter. Credits: NASA/JPL

It’s a bold, confident step forward into the solar system for NASA and the human journey to the beginning of space and time. After traveling nearly 1.36 billion miles (2.2 billion kilometers) during a journey lasting almost five years, NASA scientists and engineers prepared the Juno spacecraft for a planned 45-minute main engine burn to slow the spacecraft by around 1,200 mph (540 meters per second). At this lesser speed, the spacecraft falls quietly into mighty Jupiter’s gravity well, by entering Jupiter orbital insertion at a more controlled velocity. During this pre-insertion phase mission, specialists in NASA’s Jet Propulsion Laboratory in Pasadena, California altered Juno’s altitude to point its main engine in the right direction for the maneuver. They also increased the spacecraft’s rate of rotation from 2 to 5 revolutions per minute (RPM) to help stabilize it. 

Portrait, Charles F. Bolden, Jr., Administrator, National Aeronautics and Space Administration (NASA). Washington, DC, July 29, 2009. Photo Credit: (NASA/Bill Ingalls)
Portrait, Charles F. Bolden, Jr., Administrator, National Aeronautics, and Space Administration (NASA). Washington, DC, July 29, 2009. Photo Credit: (NASA/Bill Ingalls)

“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.” 

This infographic illustrates the radiation environments Juno has traveled through on its journey near Earth and in interplanetary space. Credits: NASA/JPL

At 8:18 p.m. PDT (11:18 p.m. EDT) on Monday, June 4, 2016, NASA’s Juno spacecraft started its 645-Newton Leros-1b main engine to decrease velocity to allow for a safe Jupiter orbital insertion. 35 minutes later, at 8:53 p.m. PDT (11:53 p.m. EDT), NASA’s Juno team received data from the spacecraft confirming a successful insertion into orbit around mighty Jupiter. A little earlier than expected, but better early, than never at all.  

Description: Scott Bolton, Div. 15, Portrait, man, 1 image Date photographed: 12/7/04 Charge number: 68OH Publication: New Hire/Professional Announcement Contact name: Brenda Decker Photographed by: Larry Walther Department name: Division: (68)
Scott Bolton, principle investigator of Juno from Southwest Research Institute in San Antonio. Credits: NASA/JPL 

“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.” 

This is the final view taken by the JunoCam instrument on NASA’s Juno spacecraft before Juno’s instruments were powered down in preparation for orbit insertion on July 4. Credits: NASA/JPL

After the successful Jupiter orbital insertion, the team turned Juno so its three huge solar arrays, shaped like a windmill, could capture the sun’s rays on 18,698 individual solar cells that give Juno its energy. At an average distance of around 484 million miles (778 million kilometers) from Sol, Jupiter is generally five times further from the sun than Earth, which means the amount of solar energy collected by Juno’s solar array’s about 25 times weaker. At this distance, despite recent advances in solar cell technology, Juno’s solar collectors only provide about 450 watts of power, enough to power four household light bulbs. 

“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 members the mission they are looking for.” 

Next, the team will prepare Juno to conduct the science data collection phase of the mission. They need to do final testing of all spacecraft subsystems, calibrate science instruments, and collect some data to enable the next phase of Juno’s mission to Jupiter.  

This illustration depicts NASA's Juno spacecraft approaching Jupiter. Credits: NASA/JPL
This illustration depicts NASA’s Juno spacecraft approaching Jupiter. Credits: NASA/JPL

“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.” 

The Juno mission’s primary science objective is to uncover clues to the origin and evolution of mighty Jupiter, the biggest planet in our solar system. Now, Juno will turn its suite of nine science instruments to the task of exploring the possible existence of a solid planetary core and mapping the gas giant’s extreme magnetic field. It will also measure the amount of water and ammonia in the deep atmosphere of Jupiter and observe its amazing, stunning auroras. If the mission goes as scripted, human knowledge and understanding of the birth and formation of giant planets will take a huge step forward, and the part Jupiter played in the origin and evolution of the solar system and life on Earth could be partly revealed. The knowledge we gain through our journey to Jupiter can even offer us useful, critical clues to the processes creating some of the bizarre creatures in the Planetary Zoo of Exoplanets.  

This trio of Junocam views of Earth was taken during Juno’s close flyby on October 9, 2013. The leftmost view shows the southern two-thirds of South America. As the spacecraft moved eastward during its flyby, the Chilean coast and the snowy line of the Andes Mountains recedes toward the limb at left on the planet. The third image includes a view of the Argentinean coastline with reflections, or specular highlights, off the Rio Negro north of Golfo San Matias, as well as cloud formations over Antarctica. Credits: NASA/JPL-Caltech/MSSS

Watch JunoCam

Join the conversation and help determine future targets for JunoCam, a visible light camera on board Juno. Right now, people around the world are talking about and voting on the images the spacecraft will take of Jupiter during its mission. They’re uploading personal images and data NASA mission specialists can use to help plan the days ahead for the Juno mission. We suggest you read the submission guidelines before submitting images or data to the official Juno website.  

Here people can read the latest news concerning Juno, watch a series of videos with announcer Bill Nye (The Science Guy) explaining the dangers and interesting things you need to know about Jupiter and its moon system and meet the team behind our journey to the biggest planet in the solar system. You can follow the story of the Juno mission from start to finish and find out about future plans for our visit. 

Watch this movie of Juno’s approach to Jupiter and moons between June 12 – 29. It starts with the spacecraft about 10 million miles from Jupiter and ends 3 million miles away from the gas giant.  

For millennium Jupiter was but a wandering star until Galileo observed transiting bodies change position with respect to the suspect star over the course of a few nights. Through these observations, he realized these bodies were moons orbiting a distant planet. He came to the revelation the Earth isn’t the center of the universe and forever changed the way we view our place in the cosmos.  

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