Roughly the size of an NBA basketball court, Juno is a spinning spacecraft. Cartwheeling through space makes the spacecraft’s pointing extremely stable and easy to control. While in orbit at Jupiter, the spinning spacecraft sweeps the fields of view of its instruments through space once for each rotation. At three rotations per minute, the instruments’ fields of view sweep across Jupiter about 400 times in the two hours it takes to fly from pole to pole.
It Uses the Power of the Sun
Jupiter’s orbit is five times farther from the sun than Earth’s, so the giant planet receives 25 times less sunlight than Earth. Juno will be the first solar-powered spacecraft we’ve designed to operate at such a great distance from the sun. Because of this, the surface area of the solar panels required to generate adequate power is quite large.
Three solar panels extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of about 66 feet. Juno benefits from advances in solar cell design with modern cells that are 50% more efficient and radiation tolerant than silicon cells available for space missions 20 years ago. Luckily, the mission’s power needs are modest, with science instruments requiring full power for only about six out of each 11-day orbit.
It Has a Protective Radiation Vault
Juno will avoid Jupiter’s highest radiation regions by approaching over the north, dropping to an altitude below the planet’s radiation belts, and then exiting over the south. To protect sensitive spacecraft electronics, Juno will carry the first radiation shielded electronics vault, a critical feature for enabling sustained exploration in such a heavy radiation environment.
Juno Science Payload:Gravity Science and Magnetometers – Will study Jupiter’s deep structure by mapping the planet’s gravity field and magnetic field.
Microwave Radiometer – Will probe Jupiter’s deep atmosphere and measure how much water (and hence oxygen) is there.
JEDI, JADE and Waves – These instruments will work to sample electric fields, plasma waves and particles around Jupiter to determine how the magnetic field is connected to the atmosphere, and especially the auroras (northern and southern lights).
JADE and JEDI
UVS and JIRAM – Using ultraviolet and infrared cameras, these instruments will take images of the atmosphere and auroras, including chemical fingerprints of the gases present.
JunoCam – Take spectacular close-up, color images.
For the first time in almost a decade, we’re going back to Jupiter. Our Juno spacecraft arrives at the king of planets on the fourth of July. From a unique polar orbit, Juno will repeatedly dive between the planet and its intense belts of charged particle radiation. Juno’s primary goal is to improve our understanding of Jupiter’s formation and evolution, which will help us understand the history of our own solar system and provide new insight into how other planetary systems form.
In anticipation, here are a few things you need to know about the Juno mission and the mysterious world it will explore:
1. This is the Big One
The most massive planet in our solar system, with dozens of moons and an enormous magnetic field, Jupiter rules over a kind of miniature solar system.
2. Origin Story
Why study Jupiter in the first place? How does the planet fit into the solar system as a whole? What is it hiding? How will Juno unlock its secrets? A series of brief videos tells the stories of Jupiter and Juno. Watch them HERE.
3. Eyes on Juno
If you really want a hands-on understanding of Juno’s flight through the Jupiter system, there’s no better tool than the “Eyes on Juno” online simulation. It uses data from the mission to let you realistically see and interact with the spacecraft and its trajectory—in 3D and across both time and space.
4. You’re on JunoCam!
Did you know that you don’t have to work for NASA to contribute to the Juno mission? Amateur astronomers and space enthusiasts everywhere are invited to help with JunoCam, the mission’s color camera. You can upload your own images of Jupiter, comment on others’ images, and vote on which pictures JunoCam will take when it reaches the Jovian system.
5. Ride Along
It’s easy to follow events from the Juno mission as they unfold. Here are several ways to follow along online: