With One Year to Jupiter, NASA's Juno Team Prepares
With just one year remaining in a five-year trek to Jupiter, the team of NASA's Juno mission is hard at work preparing for the spacecraft's expedition to the solar system's largest planet. The mission aims to reveal the story of Jupiter's formation and details of its interior structure. Data from Juno will provide insights about our solar system's beginnings, and what we learn from the mission will also enrich scientists' understanding of giant planets around other stars.
Juno is scheduled to arrive at Jupiter on July 4, 2016 (Pacific Daylight Time). Once it settles into orbit, the spacecraft will brave the hazards of Jupiter's intense radiation when it repeatedly approaches within a few thousand miles, or kilometers, of the cloud tops to collect its data.
Juno is the first mission dedicated to the study of a giant planet's interior, which it will do by mapping the planet's magnetic and gravity fields. The mission will also map the abundance of water vapor in the planet's atmosphere, providing the key to understanding which of several theories about the planet's formation is likely the correct one. In addition, Juno will travel through the previously unexplored region above the planet's poles, collecting the first images from there, along with data about electromagnetic forces and high-energy particles in the environment.
Although other spacecraft have previously visited Jupiter, the space around the planet is full of unknowns, especially the regions above the poles. With these challenges in mind, the Juno team has been busy fine-tuning their flight plan.
"We're already more than 90 percent of the way to Jupiter, in terms of total distance traveled," said Scott Bolton, Juno principal investigator at Southwest Research Institute, San Antonio. "With a year to go, we're looking carefully at our plans to make sure we're ready to make the most of our time once we arrive."
Following a detailed analysis by the Juno team, NASA recently approved changes to the mission's flight plan at Jupiter. Instead of taking 11 days to orbit the planet, Juno will now complete one revolution every 14 days. The difference in orbit period will be accomplished by having Juno execute a slightly shorter engine burn than originally planned.
The revised cadence will allow Juno to build maps of the planet's magnetic and gravity fields in a way that will provide a global look at the planet earlier in the mission than the original plan. Over successive orbits, Juno will build a virtual web around Jupiter, making its gravity and magnetic field maps as it passes over different longitudes from north to south. The original plan would have required 15 orbits to map these forces globally, with 15 more orbits filling in gaps to make the map complete. In the revised plan, Juno will get very basic mapping coverage in just eight orbits. A new level of detail will be added with each successive doubling of the number, at 16 and 32 orbits.
The slightly longer orbit also will provide a few extra days between close approaches to the planet for the team to react to unexpected conditions the spacecraft might experience in the complex environment very close to Jupiter.
"We have models that tell us what to expect, but the fact is that Juno is going to be immersed in a strong and variable magnetic field and hazardous radiation, and it will get closer to the planet than any previous orbiting spacecraft," said Bolton. "Juno's experience could be different than what our models predict -- that's part of what makes space exploration so exciting."
The revised plan lengthens Juno's mission at Jupiter to 20 months instead of the original 15, and the spacecraft will now complete 32 orbits instead of 30. But the extra time doesn't represent bonus science for the mission -- rather, it's an effect of the longer orbital period and the change in the way Juno builds its web around Jupiter. Basically, it will take Juno a bit longer to collect the full data set the mission is after, but it will get a low-resolution version of its final products earlier in the mission than originally planned.
NASA also recently approved a change to the spacecraft's initial orbit after Jupiter arrival, called the capture orbit. The revised plan splits the originally planned, 107-day-long capture orbit into two. The new approach will provide the Juno team a sneak preview of their science activities, affording them an opportunity to test the spacecraft's science instruments during a close approach to Jupiter before beginning the actual science phase of the mission. The original scenario called for an engine burn to ease Juno into Jupiter orbit, followed by a second burn 107 days later, putting the spacecraft into an 11-day science orbit. In the updated mission design, the orbit-insertion burn is followed 53.5 days later by a practice run at Jupiter with science instruments turned on, followed by another 53.5-day orbit before the final engine burn that places Juno into its new, 14-day science orbit.
In addition to myriad preparations being made on the engineering side, Juno's science team is also busy preparing to collect valuable data about the giant planet's inner workings. One piece of this science groundwork is a collection of images and spectra being obtained by powerful ground-based telescopes and NASA's Hubble Space Telescope (spectra are like chemical fingerprints of gases in the atmosphere). These data are intended to provide big-picture context for Juno's up-close observations of Jupiter, which is important for interpreting what the spacecraft's instruments will see.
With the countdown clock ticking -- this time, not toward launch, but toward arrival at their destination -- the Juno team is acutely aware of how quickly they're sneaking up on the giant planet. And their excitement is building.
"It's been a busy cruise, but the journey has provided our team with valuable experience flying the spacecraft and enhanced our confidence in Juno's design," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory, Pasadena, California. "Now it's time to gear up for Jupiter."
Juno is the second mission chosen as part of NASA's New Frontiers program of frequent, medium-class spacecraft missions that address high-priority exploration initiatives in the solar system. NASA's New Horizons mission, which will soon encounter Pluto, is the first New Frontiers mission; OSIRIS-REx is next in the lineup, slated to launch in 2016.
NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The New Frontiers Program is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of the California Institute of Technology in Pasadena.
Where is Juno?
As of June 5, 2015, Juno is approximately 460 million miles (740 million kilometers) from Earth. The one-way radio signal travel time between Earth and Juno is currently about 41 minutes. Juno is traveling at a velocity of approximately 81,000 miles per hour (about 36 kilometers per second) relative to Earth, and 22,000 miles per hour (about 10 kilometers per second) relative to the sun. Juno has now travelled 1.59 billion miles (2.56 billion kilometers, or about 17.16 AU) since launch, and has another 165 million miles (265 million kilometers or 1.77 AU) before entering Jupiter’s orbit.
The Juno spacecraft remains in excellent health and is operating nominally.
To Jupiter with JunoCam!
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.
When NASA's Juno mission arrives at Jupiter on July 4, 2016, new views of the giant planet's swirling clouds will be sent back to Earth, courtesy of its color camera, called JunoCam. But unlike previous space missions, professional scientists will not be the ones producing the processed views, or even choosing which images to capture. Instead, the public will act as a virtual imaging team, participating in key steps of the process, from identifying features of interest to sharing the finished images online.
"This is really the public's camera. We are hoping students and whole classrooms will get involved and join our team," said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio.
The Juno team has kicked off the first stage of JunoCam activity with the launch of a new Web platform on the mission's website. Now and throughout the mission, amateur astronomers are invited to submit images of Jupiter from their own telescopes. These views will be the basis for online discussions about which of Jupiter's swirls, bands and spots JunoCam should image as it makes repeated, close passes over the planet. The ground-based views will be essential for identifying and tracking changes in the planet's cloud features as Juno approaches.
"In between our close Jupiter flybys, Juno goes far from the planet, and Jupiter will shrink in JunoCam's field of view to a size too small to be useful for choosing which features to capture. So we really are counting on having help from ground-based observers," said Candy Hansen, a member of the Juno science team who leads planning for the camera.
Juno will get closer to Jupiter than any previous orbiting spacecraft, giving JunoCam the best close-up views yet of the planet's colorful cloud bands. Every 14 days, the spinning, solar-powered spacecraft will dive past the planet in just a couple of hours, gathering huge amounts of science data, plus about a dozen JunoCam images. At closest approach, Juno will snap photos from only 3,100 miles (5,000 kilometers) above Jupiter's clouds.
"JunoCam will capture high-resolution color views of Jupiter's bands, but that's only part of the story," said Diane Brown, Juno program executive at NASA Headquarters in Washington. "We'll also be treated to the first-ever views of Jupiter's north and south poles, which have never been imaged before."
Unlike most spacecraft cameras, JunoCam was specially designed to work on a spinning spacecraft. Typically, spacecraft must point very precisely at their subjects while taking a picture to avoid smearing their images. Since Juno rotates twice per minute, the Juno team designed a camera that images several lines of pixels at a time, at the right speed to cancel out the rotation and avoid smear.
Previously, the best images of Jupiter were taken by NASA's two Voyager spacecraft, which flew past the planet in 1979. JunoCam's field of view is much wider than that of Voyager's narrow-angle camera. This means every JunoCam image is a kind of panorama, and its highest-resolution images will show wide swaths of clouds. The camera also benefits from decades of technology advancement, making it lighter, less power-hungry and lower in cost.
After JunoCam data arrive on Earth, members of the public will process the images to create color pictures. The Juno team successfully tested this approach when JunoCam acquired its first high-resolution views, showing our home planet during the spacecraft's Earth flyby in October 2013.
Since the mission's beginnings, JunoCam was intended almost entirely as a public outreach tool, in contrast to the spacecraft's other instruments that will address Juno's core science questions. Juno scientists will ensure JunoCam returns a few great shots of Jupiter's polar regions, but the overwhelming majority of the camera's image targets will be chosen by the public, with the data being processed by them as well.
"We want to give people an opportunity to participate with NASA, and public involvement is key to JunoCam's success," said Bolton. "This is citizen science at its best."
Information about JunoCam's new features for amateur astronomer engagement is available at:
The JunoCam Web platform will soon add a discussion section to begin identifying features of interest on the planet for JunoCam to image.
The Juno mission website, designed and developed by Radical Media since 2011, has been augmented and updated to include new features in addition to the site's interactive JunoCam section.
Launched in 2011, the Juno mission uses every known technique to probe beneath the obscuring cloud cover of Jupiter to learn more about the planet's origins, structure, atmosphere and magnetosphere.
NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of the California Institute of Technology, in Pasadena, which manages the laboratory for NASA.
NASA's Juno Spacecraft Breaks Solar Power Distance Record
Launching from Earth in 2011, the Juno spacecraft will arrive at Jupiter in 2016 to study the giant planet from an elliptical, polar orbit. Juno will repeatedly dive between the planet and its intense belts of charged particle radiation, coming only 5,000 kilometers (about 3,000 miles) from the cloud tops at closest approach.Image credit: NASA/JPL-Caltech
NASA's Juno mission to Jupiter has broken the record to become humanity's most distant solar-powered emissary. The milestone occurred at 11 a.m. PST (2 p.m. EST, 19:00 UTC) on Wednesday, Jan. 13, when Juno was about 493 million miles (793 million kilometers) from the sun.
The previous record-holder was the European Space Agency's Rosetta spacecraft, whose orbit peaked out at the 492-million-mile (792-million-kilometer) mark in October 2012, during its approach to comet 67P/Churyumov-Gerasimenko.
"Juno is all about pushing the edge of technology to help us learn about our origins," said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio. "We use every known technique to see through Jupiter's clouds and reveal the secrets Jupiter holds of our solar system's early history. It just seems right that the sun is helping us learn about the origin of Jupiter and the other planets that orbit it."
Launched in 2011, Juno is the first solar-powered spacecraft designed to operate at such a great distance from the sun. That's why the surface area of solar panels required to generate adequate power is quite large. The four-ton Juno spacecraft carries three 30-foot-long (9-meter) solar arrays festooned with 18,698 individual solar cells. At Earth distance from the sun, the cells have the potential to generate approximately 14 kilowatts of electricity. But transport those same rectangles of silicon and gallium arsenide to a fifth rock from the sun distance, and it's a powerfully different story.
"Jupiter is five times farther from the sun than Earth, and the sunlight that reaches that far out packs 25 times less punch," said Rick Nybakken, Juno's project manager from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "While our massive solar arrays will be generating only 500 watts when we are at Jupiter, Juno is very efficiently designed, and it will be more than enough to get the job done."
Prior to Juno, eight spacecraft have navigated the cold, harsh underlit realities of deep space as far out as Jupiter. All have used nuclear power sources to get their job done. Solar power is possible on Juno due to improved solar-cell performance, energy-efficient instruments and spacecraft, a mission design that can avoid Jupiter's shadow, and a polar orbit that minimizes the total radiation. Juno's maximum distance from the sun during its 16-month science mission will be about 517 million miles (832 million kilometers), an almost five percent increase in the record for solar-powered space vehicles.
"It is cool we got the record and that our dedicated team of engineers and scientists can chalk up another first in space exploration," said Bolton. "But the best is yet to come. We are achieving these records and venturing so far out for a reason -- to better understand the biggest world in our solar system and thereby better understand where we came from."
Juno will arrive at Jupiter on July 4 of this year. Over the next year the spacecraft will orbit the Jovian world 33 times, skimming to within 3,100 miles (5,000 kilometers) above the planet's cloud tops every 14 days. During the flybys, Juno will probe beneath the obscuring cloud cover of Jupiter and study Jupiter's aurorae to learn more about the planet's origins, structure, atmosphere and magnetosphere.
NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space Systems, Denver, built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.
Solar Power Explorers
The sun powers spacecraft to Earth orbit, Mars and beyond. Here’s how NASA’s Juno mission to Jupiter became the most distant solar-powered explorer and influenced the future of space exploration powered by the sun.
NASA’s Juno Spacecraft Burns for Jupiter
This graphic shows how NASA’s Juno mission to Jupiter became the most distant solar-powered explorer and influenced the future of space exploration powered by the sun.
NASA's solar-powered Juno spacecraft successfully executed a maneuver to adjust its flight path today, Feb. 3. The maneuver refined the spacecraft’s trajectory, helping set the stage for Juno's arrival at the solar system’s largest planetary inhabitant five months and a day from now.
"This is the first of two trajectory adjustments that fine tune Juno’s orbit around the sun, perfecting our rendezvous with Jupiter on July 4th at 8:18 p.m. PDT [11:18 p.m. EDT]," said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio.
The maneuver began at 10:38 a.m. PST (1:38 p.m. EST). The Juno spacecraft's thrusters fired for 35 minutes, consumed about 1.2 pounds (.56 kilograms) of fuel, and changed the spacecraft's speed by 1 foot (0.31 meters), per second. At the time of the maneuver, Juno was about 51 million miles (82 million kilometers) from Jupiter and approximately 425 million miles (684 million kilometers) from Earth. The next trajectory correction maneuver is scheduled for May 31.
Juno was launched on Aug. 5, 2011. The spacecraft will orbit the Jovian world 33 times, skimming to within 3,100 miles (5,000 kilometers) above the planet's cloud tops every 14 days. During the flybys, Juno will probe beneath the obscuring cloud cover of Jupiter and study its aurorae to learn more about the planet's origins, structure, atmosphere and magnetosphere.
Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife -- the goddess Juno -- was able to peer through the clouds and reveal Jupiter's true nature.
NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft. The California Institute of Technology in Pasadena manages JPL for NASA.
NASA’s Juno Mission on Course for July 4 Arrival at Jupiter, Media Accreditation Open
Media accreditation now is open for events around the arrival of NASA’s Juno spacecraft at Jupiter on July 4. The spacecraft, which will reveal the story of the formation and evolution of the planet Jupiter, will enter into orbit around the gas giant that evening, five years after leaving Earth.
The event and related news conferences will be carried live on NASA Television and the agency's website. Further details and updates will be announced as they become available.
To cover Juno arrival events at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, media can begin the process of applying for credentials by sending all of the following information to: email@example.com.
Your name (as spelled on your driver’s license with middle name), title, phone number and work email
Country of citizenship
If not a U.S. citizen, are you a green card holder?
Media outlet name, address, phone number, and website
Editor's name, phone number and work email
To allow time for processing and approval, foreign nationals and representatives of foreign media outlets must apply by May 11. U.S. citizens and green card holders representing U.S. media outlets must apply by June 2. For more information about media accreditation, contact Elena Mejia at 818-354-1712 or firstname.lastname@example.org.
Media should confirm they have been credentialed before making travel arrangements. Credentialed media will have access to interview, photo and b-roll opportunities, and media briefings before and after spacecraft orbital insertion. The JPL Juno newsroom will open on June 30.
Juno will make two 53-day elliptical laps around Jupiter, before beginning the mission's science phase. At that point, the spacecraft will begin orbiting the Jovian world every 14 days, from a distance as close as 3,100 miles (5,000 kilometers). It will peer beneath Jupiter's cloud tops to learn about the planet's origins, composition and magnetosphere. Jupiter lies in the harshest radiation environment in our solar system, so this particular spacecraft orbit insertion will mark a new achievement in planetary exploration.
JPL manages the Juno mission for NASA. The principal investigator for the mission is Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by 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. JPL is a division of the California Institute of Technology in Pasadena.
Witness Juno's Arrival at Jupiter Live from JPL
Social media users are welcome to apply for access to a two-day media event culminating in the arrival of NASA's Juno spacecraft in orbit around Jupiter. Up to 25 selected participants in the July 3-4 event will tour, explore and share their experiences from NASA's Jet Propulsion Laboratory in Pasadena, California.
Writers, vloggers, photographers, educators, students, artists and other curious minds who use social media to engage specific audiences are encouraged to apply.
The attendees who are selected will tour JPL, with an anticipated stop in the Spacecraft Assembly Facility, where test hardware from the Juno mission is on display. They will also meet mission scientists and engineers; and share in the arrival of the Juno spacecraft in orbit around Jupiter, live from the JPL media site. This moment of orbit insertion, during the evening of July 4, is the culmination of the mission's five-year cruise through space, and the beginning of its 18-month voyage of discovery at Jupiter.
Registration is open now and closes at 2 p.m. PDT (5 p.m. EDT) on Wednesday, May 11, 2016. To apply, visit:
Juno's goal is to understand the origin and evolution of Jupiter. The spacecraft launched Aug. 5, 2011, and will orbit the giant planet more than 30 times, skimming to within 3,100 miles (5,000 kilometers) above the planet's cloud tops every 14 days. During the flybys, Juno will probe beneath the obscuring cloud cover of Jupiter and study its auroras to learn more about the planet's formation, structure, atmosphere and magnetosphere.
Juno's name comes from Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife -- the goddess Juno -- was able to peer through the clouds and reveal Jupiter's true nature.
JPL manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft. Caltech in Pasadena manages JPL for NASA.