Juno Transmits 1st Orbital Imagery after Swooping Arrival Over Jovian Cloud Tops and Powering Up

This color view from NASA's Juno spacecraft is made from some of the first images taken by JunoCam after the spacecraft entered orbit around Jupiter on July 4, 2016. Credits: NASA/JPL-Caltech/SwRI/MSSS
This color view from NASA's Juno spacecraft is made from some of the first images taken by JunoCam after the spacecraft entered orbit around Jupiter on July 4, 2016.  Credits: NASA/JPL-Caltech/SwRI/MSSS
This color view from NASA’s Juno spacecraft is made from some of the first images taken by JunoCam after the spacecraft entered orbit around Jupiter on July 4, 2016. Credits: NASA/JPL-Caltech/SwRI/MSSS

NASA’s newly arrived Jovian orbiter Juno has transmitted its first imagery since reaching orbit last week on July 4 after swooping over Jupiter’s cloud tops and powering back up its package of state-of-the-art science instruments for unprecedented research into determining the origin of our solar systems biggest planet.

The breathtaking image clearly shows the well known banded cloud tops in Jupiter’s atmosphere as well as the famous Great Red Spot and three of the humongous planet’s four largest moons — Io, Europa and Ganymede.

The ‘Galilean’ moons are annotated from left to right in the lead image.

Juno’s visible-light camera named JunoCam was turned on six days after Juno fired its main engine to slow down and be captured into orbit around Jupiter – the ‘King of the Planets’ following a nearly five year long interplanetary voyage from Earth.

The image was taken when Juno was 2.7 million miles (4.3 million kilometers) distant from Jupiter on July 10, at 10:30 a.m. PDT (1:30 p.m. EDT, 5:30 UTC), and traveling on the outbound leg of its initial 53.5-day capture orbit.

Juno came within only about 3000 miles of the cloud tops and passed through Jupiter’s extremely intense and hazardous radiation belts during orbital arrival over the north pole.

Illustration of NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA's Jet Propulsion Laboratory.  Credit: NASA/Lockheed Martin
Illustration of NASA’s Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA’s Jet Propulsion Laboratory. Credit: NASA/Lockheed Martin

The newly released JunoCam image is visible proof that Juno survived the do-or-die orbital fireworks on America’s Independence Day that placed the baskeball-court sized probe into orbit around Jupiter – and is in excellent health to carry out its groundbreaking mission to elucidate Jupiter’s ‘Genesis.’

“This scene from JunoCam indicates it survived its first pass through Jupiter’s extreme radiation environment without any degradation and is ready to take on Jupiter,” said Scott Bolton, principal investigator from the Southwest Research Institute in San Antonio, in a statement.

“We can’t wait to see the first view of Jupiter’s poles.”

Within two days of the nerve wracking and fully automated 35-minute-long Jupiter Orbital Insertion (JOI) maneuver, the Juno engineering team begun powering up five of the probes science instruments on July 6.

Animation of Juno 14-day orbits starting in late 2016.  Credits: NASA/JPL-Caltech
Animation of Juno 14-day orbits starting in late 2016. Credits: NASA/JPL-Caltech

All nonessential instruments and systems had been powered down in the final days of Juno’s approach to Jupiter to ensure the maximum chances for success of the critical JOI engine firing.

“We had to turn all our beautiful instruments off to help ensure a successful Jupiter orbit insertion on July 4,” said Bolton.

“But next time around we will have our eyes and ears open. You can expect us to release some information about our findings around September 1.”

Juno resumed high data rate communications with Earth on July 5, the day after achieving orbit.

We can expect to see more JunoCam images taken during this first orbital path around the massive planet.

But the first high resolution images are still weeks away and will not be available until late August on the inbound leg when the spacecraft returns and swoops barely above the clouds.

“JunoCam will continue to take images as we go around in this first orbit,” said Candy Hansen, Juno co-investigator from the Planetary Science Institute, Tucson, Arizona, in a statement.

“The first high-resolution images of the planet will be taken on August 27 when Juno makes its next close pass to Jupiter.”

All of JunoCams images will be released to the public.

During a 20 month long science mission – entailing 37 orbits lasting 14 days each – the probe will plunge to within about 2,600 miles (4,100 kilometers) of the turbulent cloud tops.

It will collect unparalleled new data that will unveil the hidden inner secrets of Jupiter’s origin and evolution as it peers “beneath the obscuring cloud cover of Jupiter and study its auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.”

The solar powered Juno spacecraft approached Jupiter over its north pole, affording an unprecedented perspective on the Jovian system – “which looks like a mini solar system” – as it flew through the giant planets intense radiation belts in ‘autopilot’ mode.

Juno is the first solar powered probe to explore Jupiter or any outer planet.

In the final weeks of the approach JunoCam captured dramatic views of Jupiter and all four of the Galilean Moons moons — Io, Europa, Ganymede and Callisto.

At the post JOI briefing on July 5, these were combined into a spectacular JunoCam time-lapse movie released by Bolton and NASA.

Watch and be mesmerized -“for humanity, our first real glimpse of celestial harmonic motion” says Bolton.

Video caption: NASA’s Juno spacecraft captured a unique time-lapse movie of the Galilean satellites in motion about Jupiter. The movie begins on June 12th with Juno 10 million miles from Jupiter, and ends on June 29th, 3 million miles distant. The innermost moon is volcanic Io; next in line is the ice-crusted ocean world Europa, followed by massive Ganymede, and finally, heavily cratered Callisto. Galileo observed these moons to change position with respect to Jupiter over the course of a few nights. From this observation he realized that the moons were orbiting mighty Jupiter, a truth that forever changed humanity’s understanding of our place in the cosmos. Earth was not the center of the Universe. For the first time in history, we look upon these moons as they orbit Jupiter and share in Galileo’s revelation. This is the motion of nature’s harmony. Credits: NASA/JPL-Caltech/MSSS

The $1.1 Billion Juno was launched on Aug. 5, 2011 from Cape Canaveral, Florida atop the most powerful version of the Atlas V rocket augmented by 5 solid rocket boosters and built by United Launch Alliance (ULA). That same Atlas V 551 version just launched MUOS-5 for the US Navy on June 24.

The Juno spacecraft was built by prime contractor Lockheed Martin in Denver.

The mission will end in February 2018 with an intentional death dive into the atmosphere to prevent any possibility of a collision with Europa, one of Jupiter’s moons that is a potential abode for life.

The last NASA spacecraft to orbit Jupiter was Galileo in 1995. It explored the Jovian system until 2003.

From Earth’s perspective, Jupiter was in conjunction with Earth’s Moon shortly after JOI during the first week in July.

Personally its thrilling to realize that an emissary from Earth is once again orbiting Jupiter after a 13 year long hiatus as seen in the authors image below – coincidentally taken the same day as JunoCam’s first image from orbit.

Juno, Jupiter and the Moon as seen from I-95 over Dunn, NC on July 10, 2016. Credit: Ken Kremer/kenkremer.com
Juno, Jupiter and the Moon as seen from I-95 over Dunn, NC on July 10, 2016. Credit: Ken Kremer/kenkremer.com

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

………….

Learn more about Juno at Jupiter, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:

July 15-18: “SpaceX launches to ISS on CRS-9, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

NASA's Juno probe captured the image data for this composite picture during its Earth flyby on Oct. 9 over Argentina,  South America and the southern Atlantic Ocean. Raw imagery was reconstructed and aligned by Ken Kremer and Marco Di Lorenzo, and false-color blue has been added to the view taken by a near-infrared filter that is typically used to detect methane. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo
NASA’s Juno probe captured the image data for this composite picture during its Earth flyby on Oct. 9 over Argentina, South America and the southern Atlantic Ocean. Raw imagery was reconstructed and aligned by Ken Kremer and Marco Di Lorenzo, and false-color blue has been added to the view taken by a near-infrared filter that is typically used to detect methane. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo

Jovians Distressed At Strange, Tiny & Silent Creatures Aboard Spacecraft

The three Lego figures inside: Galileo, Juno and Jupiter. Source: NASA

Given its historic importance – being just the second spacecraft to conduct a long-term mission to Jupiter – NASA was sure to outfit the Juno probe with some high-end memorabilia. These include the Galileo commemorative plaque*, which shows Galileo’s face and the words he wrote when he first observed Jupiter’s four largest moons in 1610 (known today as the Galilean Moons).

In addition, three commemorative figures (each measuring 4 cm high) were created especially for the mission. Created by Lego, these figurines depict the Roman god Jupiter, his wife Juno, and the astronomer Galileo Galilei – each holding an identifying object. Constructed from aluminum so they could withstand the trip and the radiation of the gas giant, these figures arrived with the probe around Jupiter on Monday, July 4th.

Much like the Juno spacecraft that is ferrying them, these figurines have spent the past 5 years in space and traversing the 869 million kilometers that lie between Earth from Jupiter. As part of Lego’s “Build Your Future” campaign,  the trio are part of an educational outreach program to inspire kids around the world to learn about science and technology.

A key part of this effort is the Building Challenge launched by Lego to raise awareness about space exploration. For this challenge, participants are asked to build their vision of the future of space exploration using Lego bricks, take pictures of their creation, and then upload them to the Lego website’s “Mission to Space” gallery. The winning creations will be featured on LEGO.com and the Gallery homepage.

NASA's Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL
NASA’s Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL

In addition, Lego’s website has new content that encourages children to learn more about the Solar System. As they state on the webpage:

“Have you ever wondered what it would be like if you could visit other planets and travel through space? Well, here’s your chance to go on a mission to Space through a partnership between NASA and LEGO Group! Pack your space lunch, and get ready to fly the International Space Station, pass the Moon, to Mars and Jupiter! Learn fun facts about our solar system, play quizzes, and get a taste of life as an astronaut and space pioneer! Round off the trip by entering an out-of-this-world building challenge.”

True to their mythological roots, the figurine of Jupiter (the Roman equivalent of Zeus) is holding a lightning bolt. Juno, his wife, is holding a magnifying glass, which represents her ability to see through the clouds that Jupiter surrounded himself with. And Galileo, the famed astronomer who was the first to view Jupiter’s moons, holds his famed telescope and an orb representing Jupiter.

These three figurines are the closest thing the Juno spacecraft has to a crew. During the next two years, they will be with the probe as it orbits Jupiter a total of 37 times, conducting surveys of Jupiter’s atmosphere, interior, magnetosphere, and gravitational field. When the mission is over, they will deorbit with the probe, crashing into Jupiter’s atmosphere to prevent any contamination of Jupiter’s moons.

Three LEGO figurines representing the Roman god Jupiter, his wife Juno and Galileo Galilei are shown here aboard the Juno spacecraft. Credits: NASA/JPL-Caltech/KSC
Three LEGO figurines representing the Roman god Jupiter, his wife Juno and Galileo Galilei are shown here aboard the Juno spacecraft. Credits: NASA/JPL-Caltech/KSC

Over the course of the past three days, numerous memes have popped up across the internet, claiming that: “When Galileo first spotted Jupiter’s largest moons, he named them after Jove’s (Zeus’) mistresses. Now, a probe named after his wife will arrive in the system, thus fulfilling a joke astronomers have been setting up for the past 400 years!” – I’m paraphrasing, of course!

Nevertheless, the observation is an apt one. And to make this witty statement complete, all those figures who had a hand in lending Jupiter the cultural significant it has (be they historical or mythological) will be represented as Juno tries to unveil Jupiter’s mysteries. Sure, those likenesses are just 4 cm in height, and they are built out of aluminum instead of marble, but it’s the thought that counts!

*The Galileo commemorative plague contains script written in Italian by Galileo’s own hand. It reads:

“On the 11th it was in this formation, and the star closest to Jupiter was half the size than the other and very close to the other so that during the previous nights all of the three observed stars looked of the same dimension and among them equally afar; so that it is evident that around Jupiter there are three moving stars invisible till this time to everyone.”

And be sure to enjoy this video of NASA’s Juno team celebrating the probe’s arrival at Jupiter:

Further Reading: NASA June, Lego

The Moon Occults Jupiter This Weekend

The Moon occults Jupiter
The Moon occults Jupiter on July 15th, 2012. Image credit and copyright: Ziad el Zaatari.

So, are you catching sight of the waxing crescent Moon returning this week to the early PM sky? The start of lunation 1157 gives folks observing Ramadan here in Morocco a reason to celebrate, as it marks the end of dawn-to-dusk fasting. Follow that Moon, as it’s about to meet up with the king of the planets this weekend.

On July 9th, the 5-day old waxing crescent Moon will pass Jupiter. You can see ’em both Saturday night, high in the western sky at dusk. For a very few observers in the southern Indian Ocean and Antarctica, the Moon will actually occult (pass in front of) Jupiter, centered on 10:11 Universal Time (UT). The Moon will be 32% illuminated crescent during the pass, and Jupiter will present a disk 34” across, just over a month past quadrature on June 4th with a current elongation of 60 degrees east of the Sun. Jupiter just passed opposition for 2016 on March 8th, and is now headed towards solar conjunction on the far side of the Sun on September 26th.

The occultation footprint for the July 9th event. Image credit: Occult 4.2 software.
The occultation footprint for the July 9th event. Image credit: Occult 4.2 software.

2016 Planetary Occultations

This is the first of four occultations of Jupiter by the Moon in 2016; the next occur over subsequent lunations on August 6th, September 2nd and 30th before the relative motions of the Moon and Jupiter carry them apart, not to meet again until October 31st, 2019. And though most observers will miss this weekend’s occultation, we’ll all get a good view of the pairing worldwide. Unfortunately, the view gets successively worse (though more central) for the next few lunations, as the occultations of Jupiter by the Moon occur close to the Sun.

Looking west on the evening of July 9th. Image credit: Stellarium.
Looking west on the evening of July 9th. Image credit: Stellarium.

Here’s another reason to celebrate and show off Jupiter at this weekend’s star party: NASA’s Juno spacecraft has just entered orbit around the gas giant world. This is only the second time a mission has orbited Jupiter (the first was Galileo) though lots have performed brief flybys, using the enormous pull of the planet for a gravitational boost en route to elsewhere. Juno is currently the only spacecraft in operation around Jove, and will conduct 36 looping science orbits around the planet before meeting its fiery end in February 2018.

A montage of daytime planets. Image credit and copyright: Shahrin Ahmad (@shahgazer).
A montage of daytime planets (and one Moon and one star). Image credit and copyright: Shahrin Ahmad (@shahgazer).

Yay, humans. Here’s another feat of visual athletics you can attempt this weekend: can you spy Jupiter near the waxing crescent Moon… in the daytime? It’s not that tough, if you know exactly where to look. Deep blue skies for maxim contrast are key, and don’t be afraid to cheat a bit and use binoculars or a wide-field DSLR shot to tease bashful Jupiter out of the daytime sky. Your best bet might be to start hunting for Jupiter 30 minutes prior to local sunset. Hey, if the Sun is still above the local horizon, it still counts! We’ve actually managed to nab Jupiter and Venus before sundown at public star parties on occasion, kicking things off a bit early.

Hunting for Jupiter in the daytime on July 9th. Image credit: Starry Night
Hunting for Jupiter in the daytime on July 9th. Image credit: Starry Night

Now for the ‘wow’ factor. The Moon is 3,474 kilometers across, and on average, 400,000 kilometers or 1.25 light seconds distant. Jupiter, at 140,000 kilometers across, is currently 5.9 Astronomical Units (AU) or 880 million kilometers away, 2,200 times more distant at 49 light minutes away. You could fit Jupiter and all of the other planets in the solar system – excluding Saturn’s rings — between the Earth and the Moon… not that you’d want such mayhem, of course. Hey; then, for the very first time in the history of human astronomy, Jupiter could occult our puny Moon…

Occultations are abruptly swift affairs in a glacially slow universe. The leading edge of the Moon moves about 30” a minute, taking 17 seconds to cover the disk of Jove. Follow Jupiter this summer, as it’ll pass just 4′ from Venus in the dusk sky on August 27th.

More to come on that soon. Here’s a final thought: has anyone ever tried to observe a radio occultation of Jupiter by the Moon? It’s certainly possible, as Jupiter is a prominent amateur radio source, crackling in the sky. And hey, the daytime sky thing wouldn’t be an issue…

We’d be thrilled to hear that, against all odds, someone on a remote windswept island or on a ship in the distant Indian Ocean actually managed to catch this weekend’s occultation!

Welcome to Jupiter – NASA’s Juno Achieves Orbit around ‘King of the Planets’

Illustration of NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA's Jet Propulsion Laboratory. Credit: NASA/Lockheed Martin
Illustration of NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA's Jet Propulsion Laboratory.
Illustration of NASA’s Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA’s Jet Propulsion Laboratory. Credit: NASA/Lockheed Martin

Welcome to Jupiter! NASA’s Juno spacecraft is orbiting Jupiter at this moment!

“NASA did it again!” pronounced an elated Scott Bolton, investigator of Juno from Southwest Research Institute in San Antonio, to loud cheers and applause from the overflow crowd of mission scientists and media gathered at the post orbit media briefing at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

After a nearly five year journey covering 1.7-billion-miles (2.8-billion-kilometers) across our solar system, NASA’s basketball court-sized Juno orbiter achieved orbit around Jupiter, the ‘King of the Planets’ late Monday night, July 4, in a gift to all Americans on our 240th Independence Day and a gift to science to elucidate our origins.

“We are in orbit and now the fun begins, the science,” said Bolton at the briefing. “We just did the hardest thing NASA’s ever done! That’s my claim. I am so happy … and proud of this team.”

And the science is all about peering far beneath the well known banded cloud tops for the first time to investigate Jupiter’s deep interior with a suite of nine instruments, and discover the mysteries of its genesis and evolution and the implications for how we came to be.

“The deep interior of Jupiter is nearly unknown. That’s what we are trying to learn about. The origin of us.”

Solar powered Juno successfully entered a polar elliptical orbit around Jupiter after completing a must-do 35-minute-long firing of the main engine known as Jupiter Orbital Insertion or JOI.

The spacecraft approached Jupiter over its north pole, affording an unprecedented perspective on the Jovian system – “which looks like a mini solar system” – as it flew through the giant planets intense radiation belts in ‘autopilot’ mode.

“The mission team did great. The spacecraft did great. We are looking great. It’s a great day,” Bolton gushes.

Engineers tracking the telemetry received confirmation that the JOI burn was completed as planned at 8:53 p.m. PDT (11:53 p.m. EDT) Monday, July 4.

Juno is only the second probe from Earth to orbit Jupiter and the first solar powered probe to the outer planets. The gas giant is two and a half times more massive than all of the other planets combined.

“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 in a statement.

“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.”

Artists concept NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter on July 4, 2016 nearly five years after launch.   Credit: NASA
Artists concept NASA’s Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter on July 4, 2016 nearly five years after launch. Credit: NASA

The do-or-die burn of Juno’s 645-Newton Leros-1b main engine started at 8:18 p.m. PDT (11:18 p.m. EDT), which had the effect of 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. There were no second chances.

All of the science instruments were turned off on June 30 to keep the focus on the nail-biting insertion maneuver and preserve battery power, said Bolton.

“So tonight through tones Juno sang to us. And it was a song of perfection. After a 1.7 billion mile journey we hit tour burn targets within one second,” Rick Nybakken, Juno project manager from JPL, gleefully reported at the briefing.

“That’s how good our team is! And that’s how well our Juno spacecraft performed tonight.”

To accomplish the burn, the spacecraft first had to adjust it’s attitude to point the engine in the required direction to slow the spacecraft and then simultaneously also had the effect that the life giving solar panels were pointing away from the sun. It the only time during the entire mission at Jupiter that the solar panels were in darkness and not producing energy.

The spacecraft’s rotation rate was also spun up from 2 to 5 revolutions per minute (RPM) to help stabilize it during JOI. Juno is spin stabilized to maintain pointing.

After the burn was complete, Juno was spun down and adjusted to point to the sun before it ran out of battery power.

We have to get the blood flowing through Juno’s veins, Bolton emphasized.

It is equipped with 18,698 individual solar cells over 60 square meters of surface on the solar arrays to provide energy. Juno is spinning like a windmill through space with its 3 giant solar arrays. It is about 540 million miles (869 million kilometers) from Earth.

Juno mission briefing on  July 5, 2016 at JPL after the successful JOI orbit insertion on July 4.  Credit: Roland Keller/rkeusa.blogspot.com
Juno mission briefing on July 5, 2016 at JPL after the successful JOI orbit insertion on July 4. Credit: Roland Keller/rkeusa.blogspot.com

Signals traveling at the speed of light take 48 minutes to reach Earth, said Nybakken.

So the main engine burn, which was fully automated, was already over for some 13 minutes before the first indications of the outcome reach Earth via a series of Doppler signals and tones.

“Tonight, 540 million miles away, Juno performed a precisely choreographed dance at blazing speeds with the largest, most intense planet in our solar system,” said Guy Beutelschies, director of Interplanetary Missions at Lockheed Martin Space Systems.

“Since launch, Juno has operated exceptionally well, and the flawless orbit insertion is a testament to everyone working on Juno and their focus on getting this amazing spacecraft to its destination. NASA now has a science laboratory orbiting Jupiter.”

“The spacecraft is now pointed back at the sun and the antenna back at Earth. The spacecraft performed well and did everything it needed to do,” he reported at the briefing.

“We are looking forward to getting all that science data to Scott and the team.”

“Juno is also the farthest mission to rely on solar power. And although they provide only 1/25th the power at Earth, they still provide over 500 watts of power at Jupiter,” said Nybakken.

Initially the spacecraft enters a long, looping polar orbit lasting about 53 days. That highly elliptical orbit will be trimmed to 14 days for the regular science orbits.

The orbits are designed to minimize contact with Jupiter’s extremely intense radiation belts. The nine science instruments are shielded inside a ½ thick vault built of Titanium to protect them from the utterly deadly radiation of some 20,000,000 rads.

During a 20 month long science mission – entailing 37 orbits lasting 14 days each – the probe will plunge to within about 3000 miles of the turbulent cloud tops and collect unprecedented new data that will unveil the hidden inner secrets of Jupiter’s origin and evolution.

But the length and number of the science orbits has changed since the mission was launched almost 5 years ago in 2011.

Originally Juno was planned to last about one year with an orbital profile involving 33 orbits of 11 days each.

I asked the team to explain the details of how and why the change from 11 to 14 days orbits and increasing the total number of orbits to 37 from 33, especially in light of the extremely harsh radiation hazards?

“The original plan of 33 orbits of 11 days was an example but there were other periods that would work,” Bolton told Universe Today.

“What we really cared about was dropping down over the poles and capturing each longitude, and laying a map or net around Jupiter.”

“Also, during the Earth flyby we went into safe mode. And as we looked at that it was a hiccup by the spacecraft but it actually behaved as it should have.”

“So we said well if that happened at Jupiter we would like to be able to recover and not lose an orbit. So we started to look at the timeline of how long it took to recover, and did we want to add a couple of days to the orbit for conservatism – to ensure the science mission.”

“So it made sense to add 3 days. It didn’t change the science and it made the probability of success even greater. So that was the basis of the change.”

“We also evaluated the radiation. And it wasn’t much different. Juno is designed to take data at a very low risk. The radiation slowly accumulates at the start. As you get to the later part of the mission, it gets a faster and faster accumulation.”

“So we still retained that conservatism as well and the overall radiation dose was pretty much the same,” Bolton explained.

“The radiation we accumulate is not just the more time you spend the more radiation,” Steve Levin, Juno Project Scientist at JPL, told Universe Today.

“Each time we come in close to the planet we get a dose of radiation. Then the spacecraft is out far from Jupiter and is relatively free from that radiation until we come in close again.”

“So just changing from 11 to 14 day orbits does not mean we get more radiation because you are there longer.”

“It’s really the number of times we come in close to Jupiter that determines how much radiation we are getting.”

Juno is the fastest spacecraft ever to arrive at Jupiter and was moving at over 165,000 mph relative to Earth and 130,000 mph relative to Jupiter at the moment of JOI.

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,” according to a NASA description.

The $1.1 Billion Juno was launched on Aug. 5, 2011 from Cape Canaveral, Florida atop the most powerful version of the Atlas V rocket augmented by 5 solid rocket boosters and built by United Launch Alliance (ULA). That same Atlas V 551 version just launched MUOS-5 for the US Navy on June 24.

The Juno spacecraft was built by prime contractor Lockheed Martin in Denver.

United Launch Alliance Atlas V liftoff with NASA’s Juno to Jupiter orbiter on Aug. 5, 2011 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer/kenkremer.com
United Launch Alliance Atlas V liftoff with NASA’s Juno to Jupiter orbiter on Aug. 5, 2011 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer/kenkremer.com

The last NASA spacecraft to orbit Jupiter was Galileo in 1995. It explored the Jovian system until 2003.

Bolton also released new views of Jupiter taken by JunoCam – the on board public outreach camera that snapped a final gorgeous view of the Jovian system showing Jupiter and its four largest moons, dancing around the largest planet in our solar system.

The newly released color image was taken on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter – just before the probe went into autopilot mode.

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. Juno obtained this color view on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter.  See timelapse movie below.  Credits: NASA/JPL-Caltech/MSSS
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. Juno obtained this color view on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter. See timelapse movie below. Credits: NASA/JPL-Caltech/MSSS

It shows a dramatic view of the clouds bands of Jupiter, dominating a spectacular scene that includes the giant planet’s four largest moons — Io, Europa, Ganymede and Callisto.

Scott Bolton and NASA also released this spectacular new time-lapse JunoCam movie at today’s briefing showing Juno’s approach to Jupiter and the Galilean Moons.

Watch and be mesmerized -“for humanity, our first real glimpse of celestial harmonic motion” says Bolton.

Video caption: NASA’s Juno spacecraft captured a unique time-lapse movie of the Galilean satellites in motion about Jupiter. The movie begins on June 12th with Juno 10 million miles from Jupiter, and ends on June 29th, 3 million miles distant. The innermost moon is volcanic Io; next in line is the ice-crusted ocean world Europa, followed by massive Ganymede, and finally, heavily cratered Callisto. Galileo observed these moons change position with respect to Jupiter over the course of a few nights. From this observation he realized that the moons were orbiting mighty Jupiter, a truth that forever changed humanity’s understanding of our place in the cosmos. Earth was not the center of the Universe. For the first time in history, we look upon these moons as they orbit Jupiter and share in Galileo’s revelation. This is the motion of nature’s harmony. Credits: NASA/JPL-Caltech/MSSS

Along the 5 year journey to Jupiter, Juno made a return trip to Earth on Oct. 9, 2013 for a flyby gravity assist speed boost that enabled the trek to the Jovian system.

During the Earth flyby (EFB), the science team observed Earth using most of Juno’s nine science instruments including, JunoCam, since the slingshot also served as an important dress rehearsal and key test of the spacecraft’s instruments, systems and flight operations teams.

The JunoCam images will be made publicly available to see and process.

During the Earth flyby, Junocam snapped some striking images of Earth as it sped over Argentina, South America and the South Atlantic Ocean and came within 347 miles (560 kilometers) of the surface.

For example a dazzling portrait of our Home Planet high over the South American coastline and the Atlantic Ocean gives a hint of what’s to come from Jupiter’s cloud tops. See our colorized Junocam mosaic of land, sea and swirling clouds, created by Ken Kremer and Marco Di Lorenzo

This colorized composite shows more than half of Earth’s disk over the coast of Argentina and the South Atlantic Ocean as the Juno probe slingshotted by on Oct. 9, 2013 for a gravity assisted acceleration to Jupiter. The mosaic was assembled from raw images taken by the Junocam imager. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo
This colorized composite shows more than half of Earth’s disk over the coast of Argentina and the South Atlantic Ocean as the Juno probe slingshotted by on Oct. 9, 2013 for a gravity assisted acceleration to Jupiter. The mosaic was assembled from raw images taken by the Junocam imager. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Rick Nybakken, Juno project manager at JPL illustrates how Juno will enter orbit around Jupiter during Juno mission briefing on July 4, 2016 at JPL. Credit: Roland Keller/rkeusa.blogspot.com
Rick Nybakken, Juno project manager at JPL illustrates how Juno will enter orbit around Jupiter during Juno mission briefing on July 4, 2016 at JPL. Credit: Roland Keller/rkeusa.blogspot.com

Juno Snaps Final View of Jovian System Ahead of ‘Independence Day’ Orbital Insertion Fireworks Tonight – Watch Live

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. Juno obtained this color view on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter. See timelapse movie below. Credits: NASA/JPL-Caltech/MSSS
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. Juno obtained this color view on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter.  Credit:  Credits: NASA/JPL-Caltech/MSSS
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. Juno obtained this color view on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter. See timelapse movie below. Credits: NASA/JPL-Caltech/MSSS

After a nearly 5 year odyssey across the solar system, NASA’s solar powered Juno orbiter is all set to ignite its main engine late tonight and set off a powerful charge of do-or-die fireworks on America’s ‘Independence Day’ required to place the probe into orbit around Jupiter – the ‘King of the Planets.’

To achieve orbit, Juno must will perform a suspenseful maneuver known as ‘Jupiter Orbit Insertion’ or JOI tonight, Monday, July 4, upon which the entire mission and its fundamental science hinges. There are no second chances!

You can be part of all the excitement and tension building up to and during that moment, which is just hours away – and experience the ‘Joy of JOI’ by tuning into NASA TV tonight!

Watch the live webcast on NASA TV featuring the top scientists and NASA officials starting at 10:30 p.m. EDT (7:30 p.m. PST, 0230 GMT) – direct from NASA’s Jet Propulsion Laboratory: https://www.nasa.gov/nasatv

Illustration of NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA's Jet Propulsion Laboratory.
Illustration of NASA’s Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA’s Jet Propulsion Laboratory. Credit: NASA/Lockheed Martin

And for a breathtaking warm-up act, Juno’s on board public outreach JunoCam camera snapped a final gorgeous view of the Jovian system showing Jupiter and its four largest moons, dancing around the largest planet in our solar system.

The newly released color image was taken on June 29, 2016, at a distance of 3.3 million miles (5.3 million kilometers) from Jupiter – just before the probe went into autopilot mode.

It shows a dramatic view of the clouds bands of Jupiter, dominating a spectacular scene that includes the giant planet’s four largest moons — Io, Europa, Ganymede and Callisto.

NASA also released this new time-lapse JunoCam movie today:

Video caption: Juno’s Approach to Jupiter: After nearly five years traveling through space to its destination, NASA’s Juno spacecraft will arrive in orbit around Jupiter on July 4, 2016. This video shows a peek of what the spacecraft saw as it closed in on its destination. Credits: NASA/JPL-Caltech/MSSS

The spacecraft is approaching Jupiter over its north pole, affording an unprecedented perspective on the Jovian system – “which looks like a mini solar system,” said Juno Principal Investigator and chief scientist Scott Bolton, from the Southwest Research Institute (SwRI) in San Antonio, Tx, at today’s media briefing at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

“The deep interior of Jupiter is nearly unknown. That’s what we are trying to learn about.”

The 35-minute-long main engine burn is preprogrammed to start at 11:18 p.m. EDT (8:18 p.m. PST, 0318 GMT). It is scheduled to last until approximately 11:53 p.m. (8:53 p.m. PST, 0353 GMT).

Juno mission briefing July 4, 2016 at JPL by Jim Green, Scott Bolton, Rick Nybakken and Heidi Becker.  Credit: Roland Keller
Juno mission briefing July 4, 2016 at JPL by Jim Green, Scott Bolton, Rick Nybakken and Heidi Becker. Credit: Roland Keller/rkeusa.blogspot.com

All of the science instruments were turned off on June 30 to keep the focus on the nail-biting insertion maneuver and preserve battery power, said Bolton. Solar powered Juno is pointed away from the sun during the engine firing.

JOI is required to slow the spacecraft so it can be captured into the gas giant’s orbit as it closes in over the north pole.

Initially the spacecraft will enter a long, looping polar orbit lasting about 53 days. That highly elliptical orbit will quickly be trimmed to 14 days for the science orbits.

The orbits are designed to minimize contact with Jupiter’s extremely intense radiation belts. The science instruments are shielded inside a ½ thick vault built of Titanium to protect them from the utterly deadly radiation – of some 20,000,000 rads.

Artist's concept of NASA's Juno spacecraft crossing the orbits of Jupiter's four largest moons -- Callisto, Gaynmede, Europa and Io -- on its approach to Jupiter. Credits: NASA/JPL-Caltech
Artist’s concept of NASA’s Juno spacecraft crossing the orbits of Jupiter’s four largest moons — Callisto, Gaynmede, Europa and Io — on its approach to Jupiter.
Credits: NASA/JPL-Caltech

Juno is the fastest spacecraft ever to arrive at Jupiter and is moving at over 165,000 mph relative to Earth and 130,000 mph relative to Jupiter.

After a five-year and 2.8 Billion kilometer (1.7 Billion mile) outbound trek to the Jovian system and the largest planet in our solar system and an intervening Earth flyby speed boost, the moment of truth for Juno is now inexorably at hand.

Signals traveling at the speed of light take 48 minutes to reach Earth, said Rick Nybakken, Juno project manager from NASA’s Jet Propulsion Laboratory, at the media briefing.

So the main engine burn, which is fully automated, will already be over for some 13 minutes before the first indications of the outcome reach Earth via a series of Doppler shifts and tones. It is about 540 million miles (869 million kilometers) from Earth.

“By the time the burn is complete, we won’t even hear about it until 13 minutes later.”

“The engine burn will slow Juno by 542 meters/second (1,212 mph) and is fully automated as it approaches over Jupiter’s North Pole,” explained Nybakken.

“The long five year cruise enabled us to really learn about the spacecraft and how it operates.”

As it travels through space, the basketball court sized Juno is spinning like a windmill with its 3 giant solar arrays.

“Juno is also the farthest mission to rely on solar power. The solar panels are 60 square meters in size. And although they provide only 1/25th the power at Earth, they still provide over 500 watts of power at Jupiter.”

Rick Nybakken, Juno project manager at JPL illustrates how Juno will enter orbit around Jupiter during Juno mission briefing on July 4, 2016 at JPL. Credit: Roland Keller
Rick Nybakken, Juno project manager at JPL illustrates how Juno will enter orbit around Jupiter during Juno mission briefing on July 4, 2016 at JPL. Credit: Roland Keller/rkeusa.blogspot.com

The protective cover that shields Juno’s main engine from micrometeorites and interstellar dust was opened on June 20.

During a 20 month long science mission – entailing 37 orbits lasting 14 days each – the probe will plunge to within about 3000 miles of the turbulent cloud tops and collect unprecedented new data that will unveil the hidden inner secrets of Jupiter’s origin and evolution.

“Jupiter is the Rosetta Stone of our solar system,” says Bolton. “It is by far the oldest planet, contains more material than all the other planets, asteroids and comets combined and carries deep inside it the story of not only the solar system but of us. Juno is going there as our emissary — to interpret what Jupiter has to say.”

During the orbits, Juno will probe beneath the obscuring cloud cover of Jupiter and study its auroras to learn more about the planet’s origins, structure, atmosphere and magnetosphere.

The $1.1 Billion Juno was launched on Aug. 5, 2011 from Cape Canaveral, Florida atop the most powerful version of the Atlas V rocket augmented by 5 solid rocket boosters and built by United Launch Alliance (ULA). That same Atlas V 551 version just launched MUOS-5 for the US Navy on June 24.

The Juno spacecraft was built by prime contractor Lockheed Martin in Denver.

Juno soars skyward to Jupiter on Aug. 5, 2011 from launch pad 41 at Cape Canaveral Air Force Station at 12:25 p.m. EDT. View from the VAB roof. Credit: Ken Kremer/kenkremer.com
Juno soars skyward to Jupiter on Aug. 5, 2011 from launch pad 41 at Cape Canaveral Air Force Station at 12:25 p.m. EDT. View from the VAB roof. Credit: Ken Kremer/kenkremer.com

Along the way Juno made a return trip to Earth on Oct. 9, 2013 for a flyby gravity assist speed boost that enabled the trek to Jupiter.

The flyby provided 70% of the velocity compared to the Atlas V launch, said Nybakken.

During the Earth flyby (EFB), the science team observed Earth using most of Juno’s nine science instruments since the slingshot also serves as an important dress rehearsal and key test of the spacecraft’s instruments, systems and flight operations teams.

Juno also went into safe mode – something the team must avoid during JOI.

What lessons were learned from the safe mode event and applied to JOI, I asked?

“We had the battery at 50% state of charge during the EFB and didn’t accurately predict the sag on the battery when we went into eclipse. We now have a validated high fidelity power model which would have predicted that sag and we would have increased the battery voltage,” Nybakken told Universe Today

“It will not happen at JOI as we don’t go into eclipse and are at 100% SOC. Plus the instruments are off which increases our power margins.”

Junocam also took some striking images of Earth as it sped over Argentina, South America and the South Atlantic Ocean and came within 347 miles (560 kilometers) of the surface.

For example the dazzling portrait of our Home Planet high over the South American coastline and the Atlantic Ocean.

For a hint of what’s to come, see our colorized Junocam mosaic of land, sea and swirling clouds, created by Ken Kremer and Marco Di Lorenzo

NASA's Juno probe captured the image data for this composite picture during its Earth flyby on Oct. 9 over Argentina,  South America and the southern Atlantic Ocean. Raw imagery was reconstructed and aligned by Ken Kremer and Marco Di Lorenzo, and false-color blue has been added to the view taken by a near-infrared filter that is typically used to detect methane. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo
NASA’s Juno probe captured the image data for this composite picture during its Earth flyby on Oct. 9 over Argentina, South America and the southern Atlantic Ocean. Raw imagery was reconstructed and aligned by Ken Kremer and Marco Di Lorenzo, and false-color blue has been added to the view taken by a near-infrared filter that is typically used to detect methane. Credit: NASA/JPL/SwRI/MSSS/Ken Kremer/Marco Di Lorenzo

The last NASA spacecraft to orbit Jupiter was Galileo in 1995. It explored the Jovian system until 2003.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Infographic about Juno’s Jupiter Orbit Insertion (JOI) maneuver on July 4, 2016.   Credit: NASA/Lockheed Martin
Infographic about Juno’s Jupiter Orbit Insertion (JOI) maneuver on July 4, 2016. Credit: NASA/Lockheed Martin

The Juno Mission

NASA's Juno spacecraft launched on August 6, 2011 and should arrive at Jupiter on July 4, 2016. Credit: NASA / JPL

Ever since Galileo first observed it through a telescope in 1610, Jupiter and its system of moons have fascinated humanity. And while many spacecraft have visited the system in the past forty years, the majority of these missions were flybys. With the exception of the Galileo space probe, the visits of these spacecraft to the Jupiter system were one of several intended objectives, taking place before they made their way deeper into the Solar System.

Having launched on August 5th, 2011, NASA’s Juno spacecraft has a different purpose in mind. Using a suite of scientific instruments, Juno will study Jupiter’s atmosphere, magnetic environment, weather patterns, and shed light on the history of its formation. In essence, it will be the first probe since the Galileo mission to orbit Jupiter, where it will spend the next two years sending information about the gas giant back to Earth.

If successful, Juno will prove to be the only other long-term mission to Jupiter. However, compared to Galileo – which spent seven years in orbit around the gas giant – Juno’s mission is planned to last for just two years. However, its improved suite of instruments are expected to provide a wealth of information in that time. And barring any mission extensions, its targeted impact on the surface of Jupiter will take place in February of 2018.

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. (NASA/JPL-Caltech)
Juno will dive between the planet and its intense belts of charged particle radiation, coming  within 5,000 kilometers (about 3,000 miles) from the cloud tops. Credit: NASA/JPL-Caltech

Background:

As part of the NASA’s New Frontiers program, the Juno mission is one of several medium-sized missions intended to explore the various bodies of the Solar System. It is currently one of three probes that NASA is operating, or in the process of building. The other two are the New Horizons probe (which flew by Pluto in 2015) and OSIRIS-REx, which is expected to fly to asteroid 101955 Bennu in 2020 and bring samples back to Earth.

During a 2003 decadal survey – titled “New Frontiers in the Solar System: An Integrated Exploration Strategy” – The National Research Council discussed destinations that would serve as the source for the first competition for the New Frontiers program. A Jupiter orbiter was identified as a scientific priority, which it was hoped would address several unanswered questions pertaining to the gas giant.

These included whether or not Jupiter had a central core (the research of which would help establish how the planet was formed), the water content of Jupiter’s atmosphere, how its weather systems can remain stable, and what the nature of the magnetic field and plasma surrounding Jupiter are. In 2005, Juno was selected for the New Frontiers program alongside New Horizons and OSIRIS-REx.

Though it was originally intended to launch in 2009, NASA budget restrictions forced a delay until August of 2011. The probe was named in honor of the Roman goddess Juno, the wife of Jupiter (the Roman equivalent of Zeus) who was able to peer through a veil of clouds that Jupiter drew around himself. The name was previously a backronym which stood for JUpiter Near-polar Orbiter as well.

Mission Profile:

The Juno mission was created for the specific purpose of studying Jupiter for the sake of learning more about the formation of the Solar System. For some time, astronomers have understood that Jupiter played an important role in the development Solar System. Like the other gas giants, it was assembled during the early stages, before our Sun had the chance to absorb or blow away the light gases in the huge cloud from which they were born.

As such, Jupiter’s composition could tell us much about the early Solar System. Similarly, the gas giants are believed to have played a major role in the process of planet formation because their huge masses allowed them to shape the orbits of other objects – planets, asteroids and comets – in their planetary systems.

However, for astronomers and planetary scientists, much still remains unknown about this massive gas giant. For instance, Jupiter’s interior structure and composition, as well as what drives its magnetic field, are still the subject of theory. Because Jupiter formed at the same time as the Sun, their chemical compositions should be similar, but research has shown that Jupiter has more heavy elements than our Sun (such as carbon and nitrogen).

In addition, there are some unanswered questions about when and where the planet formed. While it may have formed in its current orbit, some evidence suggests that it could have formed farther from the sun before migrating inward. All of these questions, it is hoped, are things the Juno mission will answer.

Technician's install Juno's titanium vault. (Image Credit: NASA/JPL-Caltech/LMSS)
Technician’s install Juno’s titanium vault. (Image Credit: NASA/JPL-Caltech/LMSS)

Having launched on August 5th, 2011, the Juno spacecraft spent the next five years in space, and will reach Jupiter on July 4th, 2018. Once in orbit, it will spend the next two years orbiting the planet a total of 37 times from pole to pole, using its scientific instruments to probe beneath the gas giant’s obscuring cloud cover.

Instrumentation:

The Juno spacecraft comes equipped with a scientific suite of 8 instruments that will allow it to study Jupiter’s atmosphere, magnetic and gravitational field, weather patterns, its internal structure, and its formational history. They include:

  • Gravity Science: Using radio waves and measuring them for Doppler effect, this instrument will measure the distribution of mass inside Jupiter to create a gravity map. Small variations in gravity along the orbital path of the probe will induce small changes in velocity. The principle investigators of this instrument are John Anderson of NASA’s Jet Propulsion Laboratory and Luciano Iess of the Sapienza University of Rome.
  • JunoCam: This visible light/telescope is the spacecraft’s only imaging device. Intended for public outreach and education, it will provide breathtaking pictures of Jupiter and the Solar System, but will operate for only seven orbits around Jupiter (due to the effect Jupiter’s radiation and magnetic field have on instruments). The PI for this instrument is Michael C. Malin, of Malin Space Science Systems
  • Jovian Auroral Distribution Experiment (JADE): Using three energetic particle detectors, the JADE instrument will measure the angular distribution, energy, and velocity vector of low energy ions and electrons in the auroras of Jupiter. The PI is David McComas of the Southwest Research Institute (SwRI).
  • Jovian Energetic Particle Detector Instrument (JEDI): Like JADE, JEDI will measure the angular distribution and the velocity vector of ions and electrons, but at high-energy and in the magnetosphere of Jupiter. The PI is Barry Mauk of NASA’s Applied Physics Laboratory.
Juno spacecraft and its science instruments. Image credit: NASA/JPL
Juno spacecraft and its science instruments. Credit: NASA/JPL
  • Jovian Infrared Aural Mapper (JIRAM): Operating in the near-infrared, this spectrometer will be responsible for mapping the upper layers of Jupiter’s atmosphere. By measuring the heat that is radiated outward, it will determine how water-rich clouds can float beneath the surface. It will also be able to assess the distribution of methane, water vapor, ammonia and phosphine in Jupiter’s atmosphere. Angioletta Coradini of the Italian National Institute for Astrophysics is the PI on this instrument.
  • Magnetometer: This instrument will be used to map Jupiter’s magnetic field, determine the dynamics of the planet’s interior and determine the three-dimensional structure of the polar magnetosphere. Jack Connemey of NASA’s Goddard Space Flight Center is the instrument’s PI.
  • Microwave Radiometer: The MR instrument will perform measurements of the electromagnetic waves that pass through the Jovian atmosphere, measuring the abundance of water and ammonia in its deep layers. In so doing, it will obtain a temperature profile at various levels and determine how deep the atmospheric circulation of Jupiter is. The PI for this instrument is Mike Janssen of the JPL.
  • Radio and Plasma Wave Sensor (RPWS): This RPWS will measure the radio and plasma spectra in Jupiter’s auroral region. In the process, it will identify the regions of auroral currents that define the planet’s radio emissions and accelerate its auroral particles. William Kurth of the University of Iowa is the PI.
  • Ultraviolet Imaging Spectrograph (UVS): The UVS will record the wavelength, position and arrival time of detected ultraviolet photons, providing spectral images of the UV auroral emissions in the polar magnetosphere. G. Randall Gladstone of the SwRI is the PI.

In addition to its scientific suite, the Juno spacecraft also carries a commemorative plaque dedicated to Galileo Galilei. The plaque was provided by the Italian Space Agency and depicts a portrait of Galileo, as well as script that had been composed by Galileo himself on the occasion that he observed Jupiter’s four largest moons (known today as the Galilean Moons).

The Galileo plague aboard the Juno spacecraft. Credit: NASA/JPL-Caltech/KSC
The Galileo plague aboard the Juno spacecraft. Credit: NASA/JPL-Caltech/KSC

The text, written in Italian and transcribed from Galileo’s own handwriting, translates as:

“On the 11th it was in this formation, and the star closest to Jupiter was half the size than the other and very close to the other so that during the previous nights all of the three observed stars looked of the same dimension and among them equally afar; so that it is evident that around Jupiter there are three moving stars invisible till this time to everyone.”

The spacecraft also carries three Lego figurines representing Galileo, the Roman god Jupiter and his wife Juno. The figure of Juno holds a magnifying glass as a sign of her searching for the truth, Jupiter holds a lightning bolt, and the figure of Galileo Galilei holds his famous telescope. Lego made these figurines out of aluminum (instead of the usual plastic) to ensure they would survive the extreme conditions of space flight.

Launch:

The Juno mission launched from Cape Canaveral Air Force Station on August 5th, 2011, atop an Atlas V rocket. After approximately 1 minute and 33 seconds, the five Solid Rocket Boosters (SRBs) reached burnout and then fell away. After 4 minutes and 26 seconds after liftoff, the Atlas V main engine cut off, followed 16 seconds later by the separation of the Centaur upper stage rocket.

After a burn that lasted for 6 minutes, the Centaur was put into its initial parking orbit. It coasted for approximately 30 minutes before its engine conducted a second firing which lasted for 9 minutes, putting the spacecraft on an Earth escape trajectory. About 54 minutes after launch, the spacecraft separated from the Centaur and began to extend its solar panels.

A year after launch, between August and September 2012, the Juno spacecraft successfully conducted two Deep Space Maneuvers designed to correct its trajectory. The first maneuver (DSM-1) occurred on August 30th, 2012, with the main engine firing for approximately 30 minutes and altering its velocity by about 388 m/s (1396.8 km/h; 867 mph).

The second maneuver (DSM-2), which had a similar duration and resulted in a similar velocity change, took place on September 14th. The two firings occurred when the probe was about 480 million km (298 million miles) from Earth, and altered the spacecraft’s speed and its Jupiter-bound trajectory, setting the stage for a gravity assist from its flyby of Earth.

Earth Flyby:

Juno’s Earth flyby took place on October 9th, 2013, after the spacecraft completed one elliptical orbit around the Sun. During its closest approach, the probe was at an altitude of about 560 kilometers (348 miles). The Earth flyby boosted Juno’s velocity by 3,900 m/s (14162 km/h; 8,800 mph) and placed the spacecraft on its final flight path for Jupiter.

During the flyby, Juno’s Magnetic Field Investigation (MAG) instrument managed to capture some low-resolution images of the Earth and Moon. These images were taken while the Juno probe was about 966,000 km (600,000 mi) away from Earth – about three times the Earth-moon separation. They were later combined by technicians at NASA’s JPL to create the video shown above.

The Earth flyby was also used as a rehearsal by the Juno science team to test some of the spacecraft’s instruments and to practice certain procedures that will be used once the probe arrives at Jupiter.

Rendezvous With Jupiter:

The Juno spacecraft reached the Jupiter system and established polar orbit around the gas giant on July 4th, 2016. It’s orbit will be highly elliptical and will take it close to the poles – within 4,300 km (2,672 mi) – before reaching beyond the orbit of Callisto, the most distant of Jupiter’s large moons (at an average distance of 1,882,700 km or 1,169,855.5 mi).

This orbit will allow the spacecraft to avoid long-term contact with Jupiter’s radiation belts, while still allowing it to perform close-up surveys of Jupiter’s polar atmosphere, magnetosphere and gravitational field. The spacecraft will spend the next two years orbiting Jupiter a total of 37 times, with each orbit taking 14 days.

Already, the probe has performed measurements of Jupiter’s magnetic field. This began on June 24th when Juno crossed the bow shock just outside Jupiter’s magnetosphere, followed by it’s transit into the lower density of the Jovian magnetosphere on June 25. Having made the transition from an environment characterized by solar wind to one dominated by Jupiter’s magnetosphere, the ship’s instruments revealed some interesting information about the sudden change in particle density.

The probe entered its polar elliptical orbit on July 4th after completing a 35-minute-long firing of the main engine, known as Jupiter Orbital Insertion (or JOI). As the probe approached Jupiter from above its north pole, it was afforded a view of the Jovian system, which it took a final picture of before commencing JOI.

On July 10th, the Juno probe transmitted its first imagery from orbit after powering back up its suite of scientific instruments. The images were taken when the spacecraft was 4.3 million km (2.7 million mi) from Jupiter and on the outbound leg of its initial 53.5-day capture orbit. The color image shows atmospheric features on Jupiter, including the famous Great Red Spot, and three of the massive planet’s four largest moons – Io, Europa and Ganymede, from left to right in the image.

While the mission team had hoped to reduce Juno’s orbital period to 14 days, thus allowing for it to conduct a total of 37 perijoves before mission’s end. However, due to a malfunction with the probe’s helium valves, the firing was delayed. NASA has since announced that it will not conduct this engine firing, and that the probe will conduct a total perijoves in total before the end of its mission.

End of Mission:

The Juno mission is set to conclude in February of 2018, after completing 12 orbits of Jupiter. At this point, and barring any mission extensions, the probe will be de-orbited to burn up in Jupiter’s outer atmosphere. As with the Galileo spacecraft, this is meant be to avoid any possibility of impact and biological contamination with one of Jupiter’s moons.

The mission is managed by the JPL, and its principal investigator is Scott Bolton of the Southwest Research Institute. NASA’s Launch Services Program, located at the Kennedy Space Center in Florida, is responsible for managing launch services for the probe. The Juno mission is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Ala.

As of the writing of this article, the Juno mission is one day, four hours and fifty-five minutes away from its historic arrival with Jupiter. Check out NASA’s Juno mission page to get up-to-date information on the mission, and stay tuned to Universe Today for updates!

We have written many interesting articles about Jupiter here at Universe today. Here’s Juno Blasts off on Science Trek to Discover Jupiter’s Genesis, Jupiter Bound Juno snaps Dazzling Gallery of Planet Earth Portraits, Understanding Juno’s Orbit: An Interview with NASA’s Scott Bolton, NASA’s Juno probe Gets Gravity Speed Boost during Earth Flyby But Enters ‘Safe Mode.

Astronomy cast also has relevant episodes on the subject. Here’s Episode 59: Jupiter, and Episode 232: Galileo Spacecraft,

For more information, check out NASA’s Juno mission page, and the Southwest Research Institute’s Juno page.

NASA Approves New Horizons Extended KBO Mission, Keeps Dawn at Ceres

New Horizons trajectory and the orbits of Pluto and 2014 MU69.
New Horizons trajectory and the orbits of Pluto and 2014 MU69.
New Horizons trajectory and the orbits of Pluto and 2014 MU69.

In an ‘Independence Day’ gift to a slew of US planetary research scientists, NASA has granted approval to nine ongoing missions to continue for another two years this holiday weekend.

The biggest news is that NASA green lighted a mission extension for the New Horizons probe to fly deeper into the Kuiper Belt and decided to keep the Dawn probe at Ceres forever, rather than dispatching it to a record breaking third main belt asteroid.

And the exciting extension news comes just as the agency’s Juno probe is about to ignite a do or die July 4 fireworks display to achieve orbit at Jupiter – detailed here.

“Mission approved!” the researchers gleefully reported on the probes Facebook and Twitter social media pages.

“Our extended mission into the #KuiperBelt has been approved. Thanks to everyone for following along & hopefully the best is yet to come.

Dwarf planet Ceres is shown in this false-color renderings, which highlight differences in surface materials.  The image is centered on Ceres brightest spots at Occator crater. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Dwarf planet Ceres is shown in this false-color renderings, which highlight differences in surface materials. The image is centered on Ceres brightest spots at Occator crater. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The New Horizons spacecraft will now continue on course in the Kuiper Belt towards an small object known as 2014 MU69, to carry out the most distant close encounter with a celestial object in human history.

“Here’s to continued success!”

The spacecraft will rendezvous with the ancient rock on New Year’s Day 2019.

Researchers say that 2014 MU69 is considered as one of the early building blocks of the solar system and as such will be invaluable to scientists studying the origin of our solar system how it evolved.

It was almost exactly one year ago on July 14, 2015 that New Horizons conducted Earth’s first ever up close flyby and science reconnaissance of Pluto – the most distant planet in our solar system and the last of the nine planets to be explored.

Pluto Explored at Last. The New Horizons mission team celebrates successful flyby of Pluto in the moments after closest approach at 7:49 a.m. EDT on July 14, 2015.   New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO., left, Johns Hopkins University Applied Physics Laboratory (APL) Director Ralph Semmel, center, and New Horizons Co-Investigator Will Grundy Lowell Observatory hold an enlarged print of an U.S. stamp with their suggested update after Pluto became the final planet in our solar system to be explored by an American space probe (crossing out the words ‘not yet’) - at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.  Credit: Ken Kremer/kenkremer.com
Pluto Explored at Last. The New Horizons mission team celebrates successful flyby of Pluto in the moments after closest approach at 7:49 a.m. EDT on July 14, 2015. New Horizons Principal Investigator Alan Stern of Southwest Research Institute (SwRI), Boulder, CO., left, Johns Hopkins University Applied Physics Laboratory (APL) Director Ralph Semmel, center, and New Horizons Co-Investigator Will Grundy Lowell Observatory hold an enlarged print of an U.S. stamp with their suggested update after Pluto became the final planet in our solar system to be explored by an American space probe (crossing out the words ‘not yet’) – at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. Credit: Ken Kremer/kenkremer.com

The immense volume of data gathered continues to stream back to Earth every day.

“The New Horizons mission to Pluto exceeded our expectations and even today the data from the spacecraft continue to surprise,” said NASA’s Director of Planetary Science Jim Green at NASA HQ in Washington, D.C.

“We’re excited to continue onward into the dark depths of the outer solar system to a science target that wasn’t even discovered when the spacecraft launched.”

This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Annotated with informal place names. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com
This new global mosaic view of Pluto was created from the latest high-resolution images to be downlinked from NASA’s New Horizons spacecraft and released on Sept. 11, 2015. The images were taken as New Horizons flew past Pluto on July 14, 2015, from a distance of 50,000 miles (80,000 kilometers). This new mosaic was stitched from over two dozen raw images captured by the LORRI imager and colorized. Annotated with informal place names. Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Marco Di Lorenzo/Ken Kremer/kenkremer.com

While waiting for news on whether NASA would approve an extended mission, the New Horizons engineering and science team already ignited the main engine four times to carry out four course changes in October and November 2015, in order to preserve the option of the flyby past 2014 MU69 on Jan 1, 2019.

Green noted that mission extensions into fiscal years 2017 and 2018 are not final until Congress actually passes sufficient appropriation to fund NASA’s Planetary Science Division.

“Final decisions on mission extensions are contingent on the outcome of the annual budget process.”

Tough choices were made even tougher because the Obama Administration has cut funding for the Planetary Sciences Division – some of which was restored by a bipartisan majority in Congress for what many consider NASA’s ‘crown jewels.’

NASA’s Dawn asteroid orbiter just completed its primary mission at dwarf planet Ceres on June 30, just in time for the global celebration known as Asteroid Day.

“The mission exceeded all expectations originally set for its exploration of protoplanet Vesta and dwarf planet Ceres,” said NASA officials.

The Dawn science team had recently submitted a proposal to break out of orbit around the middle of this month in order to this conduct a flyby of the main belt asteroid Adeona.

Green declined to approve the Dawn proposal, citing additional valuable science to be gathered at Ceres.

The long-term monitoring of Ceres, particularly as it gets closer to perihelion – the part of its orbit with the shortest distance to the sun — has the potential to provide more significant science discoveries than a flyby of Adeona,” he said.

The funding required for a multi-year mission to Adeona would be difficult in these cost constrained times.

However the spacecraft is in excellent shape and the trio of science instruments are in excellent health.

Dawn arrived at Ceres on March 6, 2015 and has been conducting unprecedented investigation ever since.

Dawn is Earth’s first probe in human history to explore any dwarf planet, the first to explore Ceres up close and the first to orbit two celestial bodies.

The asteroid Vesta was Dawn’s first orbital target where it conducted extensive observations of the bizarre world for over a year in 2011 and 2012.

The mission is expected to last until at least later into 2016, and possibly longer, depending upon fuel reserves.

Due to expert engineering and handling by the Dawn mission team, the probe unexpectedly has hydrazine maneuvering fuel leftover.

Dawn will remain at its current altitude at the Low Altitude Mapping Orbit (LAMO) for the rest of its mission, and indefinitely afterward, even when no further communications are possible.

Green based his decision on the mission extensions on the biannual peer review scientific assessment by the Senior Review Panel.

Dawn was launched in September 2007.

The other mission extensions – contingent on available resources – are: the Mars Reconnaissance Orbiter (MRO), Mars Atmosphere and Volatile EvolutioN (MAVEN), the Opportunity and Curiosity Mars rovers, the Mars Odyssey orbiter, the Lunar Reconnaissance Orbiter (LRO), and NASA’s support for the European Space Agency’s Mars Express mission.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

Jupiter’s Magnetosphere Will Blow Your Mind While it Kills Your Spacecraft

Jupiter has an extremely powerful magnetic field. Ganymede has one, too, and is the only moon with one. Jupiter's envelops Ganymede's and their interactions are just part of the pair's complicated relationship. Image Credit: NASA Goddard Space Flight Center.

Jupiter is a huge planet, but its magnetosphere is mind-blowingly massive. It extends out to nearly 5 million kilometers (3 million miles) wide on average, 150 times wider than Jupiter itself and almost 15 times wider than the Sun, making it one of the largest structures in the Solar System.

“If you were to look up into the night sky and if we could see the outline of Jupiter’s magnetosphere, it would be about the size of the Moon in our sky,” said Jack Connerney, deputy principal investigator and head of the Juno mission magnetometer team. “It’s a very large feature in our Solar System, and it’s a pity we can’t see it.”

But the Juno spacecraft is about to change our understanding of Jupiter’s magnetosphere and allow scientists to “see” for the first time Jupiter’s magnetic field.

And today, NASA announced that Juno has entered Jupiter’s magnetic field. Listen to the video below as the spacecraft gathered data as it crossed the bow shock:

A magnetosphere is the area of space around a planet that is controlled by the planet’s magnetic field. The stronger the magnetic field, the larger the magnetosphere. It is estimated that Jupiter’s magnetic field is about 20,000 times stronger than Earth’s.

Jupiter has spectacular aurora, such as this view captured by the Hubble Space Telescope. Auroras are formed when charged particles in the space surrounding the planet are accelerated to high energies along the planet's magnetic field. Credit: NASA, ESA, and J. Nichols (University of Leicester)
Jupiter has spectacular aurora, such as this view captured by the Hubble Space Telescope. Auroras are formed when charged particles in the space surrounding the planet are accelerated to high energies along the planet’s magnetic field. Credit: NASA, ESA, and J. Nichols (University of Leicester)

Magnetic fields are produced by what are known as dynamos – an electric current created from the convection motion of a planet’s interior. Earth’s magnetic field is generated by its circulating core of molten iron and nickel. But what creates Jupiter’s dynamo? Is it like Earth’s or could it be very different? Jupiter consists predominantly of hydrogen and helium, and it is currently unknown if there is a rocky core at the center of the planet.

“With Jupiter, we don’t know what material is producing the planet’s magnetic field,” said Jared Espley, Juno program scientist for NASA Headquarters, “What material is present and how deep down it lies is one of the questions Juno is designed to answer.”

Juno has a pair of magnetometers to basically look inside the planet. The magnetometers will allow scientists to map Jupiter’s magnetic field with high accuracy and observe variations in the field over time. The instruments will be able to show how the magnetic field is generated by dynamo action deep in the planet’s interior, providing the first look at what the magnetic field looks like from the surface of the dynamo where it is generated.

“The best way to think of a magnetometer is like a compass,” said Connerney. “Compasses record the direction of a magnetic field. But magnetometers expand on that capability and record both the direction and magnitude of the magnetic field.”

But Jupiter presents a lot of problems as far as being nice to instruments. Trapped within the magnetosphere are charged particles from the Sun that form intense radiation belts around the planet. These belts are similar to the Earth’s Van Allen belts, but are many millions of times stronger.

To help protect the spacecraft and instrument electronics, Juno has a radiation vault about the size of a car trunk made of titanium that limits the radiation exposure to Juno’s command and data handling box (the spacecraft’s brain), power and data distribution unit (its heart) and about 20 other electronic assemblies. But the instruments themselves need to be outside of the vault in order to make their observations.

Workers place the special radiation vault for NASA's Juno spacecraft onto the propulsion module. Image credit: NASA/JPL-Caltech/LMSS
Workers place the special radiation vault for NASA’s Juno spacecraft onto the propulsion module. Image credit: NASA/JPL-Caltech/LMSS

The magnetometer sensors are on a boom attached to one of the solar arrays, placing them about 40 feet (12 meters) from the body of the spacecraft. This helps ensure that the rest of the spacecraft does not interfere with the magnetometer.
But there are other ways to help limit the amount of radiation exposure, at least in the first part of the mission.

Scientists designed a path that takes Juno around Jupiter’s poles so that the spacecraft spends the least amount of time possible in those blistering radiation belts around Jupiter’s equator. Engineers also used designs for electronics already approved for the Martian radiation environment, which is harsher than Earth’s, though not as harsh as Jupiter’s.

That elliptical orbit — between radiation belt and the planet — also puts the spacecraft very close to Jupiter, about 5,000 km above the cloud tops, enabling a close-up look at this amazing planet.

“This is our first opportunity to do very precise, high-accuracy mapping of the magnetic field of another planet,” Connerney said. “We are going to be able to explore the entire three-dimensional space around Jupiter, wrapping Jupiter in a dense net of magnetic field observations completely covering the sphere.”

By studying Jupiter’s magnetosphere, scientists will gain a better understanding about how Jupiter’s magnetic field is generated. They also hope to measure how fast Jupiter is spinning, determine whether the planet has a solid core, and learn more about Jupiter’s formation.

“It’s always incredible to be the first person in the world to see anything,” Connerney said, “and we stand to be the first to look down upon the dynamo and see it clearly for the first time.”

Further reading: Juno mission page, NASA article on Juno’s magnetometer.

Juno and the Deep Space Network: Bringing The Data Home

NASA's Deep Space Network is responsible for communicating with Juno as it explores Jupiter. Pictured is the Goldstone facility in California, one of three facilities that make up the Network. Image: NASA/JPL
NASA's Deep Space Network is responsible for communicating with spacecraft. Pictured is the Goldstone facility in California, one of three facilities that make up the Network. Image: NASA/JPL

The much-anticipated arrival of NASA’s Juno spacecraft at Jupiter is almost here. Juno will answer many questions about Jupiter, but at the cost of a mission profile full of challenges. One of those challenges is communicating with Juno as it goes about its business in the extreme radiation environment around Jupiter. Communications with Juno rely on a network of radio dishes in strategic locations around the world, receivers cooled to almost absolute zero, and a team of dedicated people.

The task of communicating with Juno falls to NASA’s Deep Space Network (DSN), a system of three facilities around the world whose job it is to communicate with all of the spacecraft that venture outside Earth’s vicinity. That network is in the hands of Harris Corporation, experts in all sorts of communications technologies, who are contracted to run these crucial facilities.

The person responsible is Sonny Giroux, DSN Program Manager at Harris. In an interview with Universe Today, Sonny explained how the DSN works, and describes some of the challenges the Juno mission poses.

“The network itself consists of three primary communication facilities; one in Goldstone, California, out in the middle of the Mojave Desert. The other facility is in Madrid Spain, and the third is in Canberra Australia. These three facilities are separated by about 120 degrees, which means that any spacecraft that’s out there is capable of communicating with Earth at any point in time,” said Giroux.

Deep Space Network facilities are positioned 120 degrees apart to give total sky coverage. Image: NASA/JPL
Deep Space Network facilities are positioned 120 degrees apart to give total sky coverage. Image: NASA/JPL

“Each facility has several antennae, the largest of which is 70 m in diameter, about the size of a football field. These antennae can be aimed at any angle. Then there are smaller antennae at 34 m in size, and we have a number of those at each complex.”

According to Giroux, the dishes can work independently, or be arrayed together, depending on requirements. At the DSN website, you can see which antenna is communicating with which of NASA’s missions at any time.

At the Deep Space Network's website, you can see which of the network's dishes are communicating with which spacecraft. Image: NASA/JPL/DSN
At the Deep Space Network’s website, you can see which of the network’s dishes are communicating with which spacecraft. During Juno’s mission, you can expect to see its name beside many of the dishes. Image: NASA/JPL/DSN

Juno is a complex mission with a dynamic orbit, and Jupiter itself is an extreme radiation environment. Juno will have to weave its way through Jupiter’s radiation belts in its polar orbit. According to Giroux, this creates additional communication problems for the DSN.

“As Juno goes into its orbital insertion phase, the spacecraft will have to turn away from Earth. Our signal strength will drop dramatically,” Giroux said. “In order to capture the data that Juno is going to send, we’re going to array all of our antennae at Goldstone and Canberra together.”

Juno's orbit around Jupiter will be highly elliptical as it contends with Jupiter's powerful radiation belts. Image: NASA/JPL
Juno’s orbit around Jupiter will be highly elliptical as it contends with Jupiter’s powerful radiation belts. Image: NASA/JPL

This means that a total of 9 antennae will be arrayed in two groups to communicate with Juno. The 4 dishes at the Canberra, Australia site will be arrayed together, and the 5 dishes at the Goldstone, California site will be arrayed together.

This combined strength is crucial to the success of Juno during JOI (Juno Orbital Insertion.) Said Giroux, “We need to bring Juno’s signal strength up to the maximum amount that we can. We need to know what phases Juno is in as it executes its sequence.”

“We’ve never arrayed all of our antennae together like this. This is a first for Juno.”

This combined receiving power is a first for the DSN, and another first for the Juno mission. “We’ve never arrayed all of our antennae together like this,” said Giroux. “This is a first for Juno. We’ve done a couple together before for a spacecraft like Voyager, which is pretty far out there, but never all of them like this. In order to maximize our success with Juno, we’re arraying everything. It will be the first time in our history that we’ve had to array together all of our assets.”

Arraying multiple dishes together provides another benefit too, as Giroux told us. “The DSN is able to have two centres view the spacecraft at the same time. If one complex goes down for whatever reason, we would have the other one still available to communicate with the spacecraft.”

The most visible part of the DSN are the antennae themselves. But the electronics at the heart of the system are just as important. And they’re unique in the world, too.

“We cool them down to almost absolute zero to remove all of the noise out.”

“We have very specialized receivers that are built for the DSN. We cool them down to almost absolute zero to remove all of the noise out. That allows us to really focus on the signal that we’re looking for. These are unique to DSN,” said Giroux.

Juno itself has four different transmitters on-board. Some are able to transmit a lot of data, and some can transmit less. These will be active at different times, and form part of the challenge of communicating with Juno. Giroux told us, “Juno will be cycling through all four as it performs its insertion and comes back out again on the other side of the planet.”

“We just get the ones and zeroes…”

The DSN is a communications powerhouse, the most powerful tool ever devised for communicating in space. But it doesn’t handle the science. “DSN for the most part will receive whatever the spacecraft is sending to us. We just get the ones and zeroes and relay that data over to the mission. It’s the mission that breaks that down and turns it into science data.”

The three facilities that make up the DSN. Each is separated by 120 degrees. Image: NASA/JPL
The three facilities that make up the DSN. Each is separated by 120 degrees. Image: NASA/JPL

Juno will be about 450 million miles away at Jupiter, which is about a 96 minute round trip for any signal. That great distance means that Juno’s signal strength is extremely weak. But it won’t be the weakest signal that the DSN contends with. A testament to the strength of the DSN is the fact that it’s still receiving transmissions from the Voyager probes, which are transmitting at miniscule power levels. According to Giroux, “Voyager is at a billionth of a billionth of a watt in terms of its signal strength.”

Juno is different than other missions like New Horizons and Voyager 1 and 2. Once Juno is done, it will plunge into Jupiter and be destroyed. So all of its data has to be captured quickly and efficiently. According to Giroux, that intensifies the DSN’s workload for the Juno mission.

“Juno is different. We’ve got to make sure to capture that data regularly.”

“Juno has a very defined mission length, with start and stop dates. It will de-orbit into Jupiter when it’s finished its science phase. That’s different than other missions like New Horizons where it has long periods where its able to download all of the data it’s captured. Juno is different. We’ve got to make sure to capture that data regularly. After JOI we’ll be in constant communication with Juno to make sure that’s happening.”

To whet our appetites, the ESO has released these awesome IR images of Jupiter, taken by the VLT. Credit: ESO
In preparation for the arrival of Juno, the ESO’s released stunning IR images of Jupiter, taken by the VLT. Credit: ESO

The next most important event in Juno’s mission is its orbital insertion around Jupiter, and Giroux and the team are waiting for that just like the rest of us are. “Juno’s big burn as it slows itself enough to be captured by Jupiter is a huge milestone that we’ll be watching for,” said Giroux.

The first signal that the DSN receives will be a simple three second beep. “Confirmation of the insertion will occur at about 9:40 p.m.,” said Giroux. That signal will have been sent about 45 minutes before that, but the enormous distance between Earth and Jupiter means a long delay in receiving it. But once we receive it, it will tell us that Juno has finished firing its engine for orbital insertion. Real science data, including images of Jupiter, will come later.

“We want to see a successful mission as much as anybody else.”

All of the data from the DSN flows through the nerve center at NASA’s Jet Propulsion Laboratory. When the signal arrives indicating that Juno has fired its engines successfully, Giroux and his team will be focussed on that facility, where news of Juno’s insertion will first be received. And they’ll be as excited as the rest of us to hear that signal.

“We want to see a successful mission as much as anybody else. Communicating with spacecraft is our business. We’ll be watching the same channels and websites that everybody else will be watching with bated breath,” said Giroux.

“Its great to be a part of the network. It’s pretty special.”

Very Large Telescope Images Of Jupiter Prepare Us For Juno Arrival

In preparation for the arrival of Juno, the ESO's released stunning IR images of Jupiter, taken by the VLT. Credit: ESO
In preparation for the arrival of Juno, the ESO's released stunning IR images of Jupiter, taken by the VLT. Credit: ESO

Launching back in 2011, NASA’s Juno mission has spent the past five years traversing the gulf that lies between Earth and Jupiter. When it arrives (in just a few days time!), it will be the second long-term mission to the gas giant in history. And in the process, it will obtain information about its composition, weather patterns, magnetic and gravitational fields, and history of formation.

With just days to go before this historic rendezvous takes place, the European Southern Observatory is taking the opportunity to release some spectacular infrared images of Jupiter. Taken with the Very Large Telescope (VLT), these images are part of a campaign to create high-resolutions maps of the planet, and provide a preview of the work that Juno will be doing in the coming months.

Using the VTL Imager and Spectrometer for mid-Infrared (VISIR) instrument, the ESO team – led by Dr. Leigh Fletcher of the University of Leicester – hopes that their efforts to map the planet will improve our understanding of Jupiter’s atmosphere. Naturally, with the upcoming arrival of Juno, some may wonder if these efforts are necessary.

The Very Large Telescoping Interferometer firing it's adaptive optics laser. Credit: ESO/G. Hüdepohl
Using images obtained by the Very Large Telescope, an ESO team managed to obtain detailed IR images of Jupiter’s atmosphere. Credit: ESO/G. Hüdepohl

After all, ground-based telescopes like the VLT are forced to contend with limitations that space-based probes are not. These include interference from our constantly-shifting atmosphere, not to mention the distances between Earth and the object in question. But in truth, the Juno mission and ground-based campaigns like these are often highly complimentary.

For one, in the past few months, while Juno was nearing in on its destination, Jupiter’s atmosphere has undergone some significant shifts. Mapping these is important to Juno‘s upcoming arrival, at which point it will be attempting to peer beneath Jupiter’s thick clouds to discern what is going on beneath. In short, the more we know about Jupiter’s shifting atmosphere, the easier it will be to interpret the Juno data.

As Dr. Fletcher described the significance of his team’s efforts:

These maps will help set the scene for what Juno will witness in the coming months. Observations at different wavelengths across the infrared spectrum allow us to piece together a three-dimensional picture of how energy and material are transported upwards through the atmosphere.”

Like all ground-based efforts, the ESO campaign – which has involved the use of several telescopes based in Hawaii and Chile, as well as contributions from amateur astronomers around the world – faced some serious challenges (like the aforementioned interference). However, the team used a technique known as “lucky imaging” to take the breathtaking snapshots of Jupiter’s turbulent atmosphere.

This view compares a lucky imaging view of Jupiter from VISIR (left) at infrared wavelengths with a very sharp amateur image in visible light from about the same time (right). Credit: ESO/L.N. Fletcher/Damian Peach
This view compares a lucky imaging view of Jupiter from VISIR (left) at infrared wavelengths with a very sharp amateur image in visible light from about the same time (right). Credit: ESO/L.N. Fletcher/Damian Peach

What this comes down to is taking many sequences of images with very short exposures, thus producing thousands of individual frames. The lucky frames, those where the image are least affected by the atmosphere’s turbulence, are then selected while the rest discarded. These selected frames are aligned and combined to produce final pictures, like the one shown above.

In addition to providing information that would be of use to the Juno mission, the ESO’s campaign has value that extends beyond the space-based mission. As Glenn Orton, the leader of ESO’s ground-based campaign, explained, observations like these are valuable because they help to advance our understanding of planets as a whole, and provide opportunities for astronomers from all over the world to collaborate.

“The combined efforts of an international team of amateur and professional astronomers have provided us with an incredibly rich dataset over the past eight months,” he said. “Together with the new results from Juno, the VISIR dataset in particular will allow researchers to characterize Jupiter’s global thermal structure, cloud cover and distribution of gaseous species.”

The Juno probe will be arriving at Jupiter this coming Monday, July 4th. Once there, it will spend the next two years orbiting the gas giant, sending information back to Earth that will help to advance our understanding of not only Jupiter, but the history of the Solar System as well.

Further Reading: ESO