nasa Juno Mission Thread - Jupiter Orbiter

[BetaguyGZT]

 

 

NASA Juno Mission Site | Mission Juno Site | Juno Official Twitter | Juno Launch (Aug 5, 2011) 

 

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Juno Spacecraft and Instruments

 

The Juno spacecraft launched aboard an Atlas V-551 rocket from Cape Canaveral, Fla., on Aug. 5, 2011, and will reach Jupiter in July 2016. The spacecraft will orbit Jupiter 32 times, skimming to within 3,100 miles (5,000 kilometers) above the planet's cloud tops, for approximately one year.

Juno uses a spinning solar-powered spacecraft in a highly elliptical polar orbit that avoids most of Jupiter's high radiation regions. The designs of the individual instruments are straightforward and the mission does not require the development of any new technologies.

 

Juno spacecraft and its science instruments. Image credit: NASA/JPL
Download higher resolution (JPG 544 kb)

Juno's scientific payload includes:

A gravity/radio science system (Gravity Science)

A six-wavelength microwave radiometer for atmospheric sounding and composition (MWR)

A vector magnetometer (MAG)

Plasma and energetic particle detectors (JADE and JEDI)

A radio/plasma wave experiment (Waves)

An ultraviolet imager/spectrometer (UVS)

An infrared imager/spectrometer (JIRAM)

The spacecraft will also carry a color camera, called JunoCam, to provide the public with the first detailed glimpse of Jupiter's poles.

Rotating Spacecraft

For Juno, like NASA’s earlier Pioneer spacecraft, spinning makes the spacecraft's pointing extremely stable and easy to control. Just after launch, and before its solar arrays are deployed, Juno will be spun-up by rocket motors on its still attached second-stage rocket booster. 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.

Solar Power

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 designed by NASA to operate at such a great distance from the sun, thus the surface area of 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 (20 meters). The solar panels will remain in sunlight continuously from launch through end of mission, except for a few minutes during the Earth flyby. Before launch, the solar panels will be folded into four-hinged segments so that the spacecraft can fit into the launch vehicle.

Juno benefits from advances in solar cell design with modern cells that are 50 percent more efficient and radiation tolerant than silicon cells available for space missions 20 years ago. The mission’s power needs are modest, with science instruments requiring full power for only about six hours out of each 11-day orbit (during the period near closest approach to the planet). With a mission design that avoids any eclipses by Jupiter, minimizes damaging radiation exposure and allows all science measurements to be taken with the solar panels facing the sun, solar power is a perfect fit for Juno.

Electronics Vault

Juno will avoid Jupiter's highest radiation regions by approaching over the north, dropping to an altitude below the planet's radiation belts – which are analogous to Earth’s Van Allen belts, but far more deadly – 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. This feature of the mission is relevant to NASA's Vision for Space Exploration, which addresses the need for protection against harsh radiation in space environments beyond the safety

of low-Earth orbit.

Orbital insertion is scheduled for early July 2016.  

[Draggendrop Veteran]

NASA’s Juno Spacecraft to Risk Jupiter’s Fireworks for Science

 

This artist's rendering shows NASA's Juno spacecraft making one of its close passes over Jupiter.
Credits: NASA/JPL-Caltech

 

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On July 4, NASA will fly a solar-powered spacecraft the size of a basketball court within 2,900 miles (4,667 kilometers) of the cloud tops of our solar system’s largest planet.

 

As of Thursday, Juno is 18 days and 8.6 million miles (13.8 million kilometers) from Jupiter. On the evening of July 4, Juno will fire its main engine for 35 minutes, placing it into a polar orbit around the gas giant. During the flybys, 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.

 

"At this time last year our New Horizons spacecraft was closing in for humanity’s first close views of Pluto,” said Diane Brown, Juno program executive at NASA Headquarters in Washington. “Now, Juno is poised to go closer to Jupiter than any spacecraft ever before to unlock the mysteries of what lies within.”

 

A series of 37 planned close approaches during the mission will eclipse the previous record for Jupiter set in 1974 by NASA’s Pioneer 11 spacecraft of 27,000 miles (43,000 kilometers). Getting this close to Jupiter does not come without a price -- one that will be paid each time Juno's orbit carries it toward the swirling tumult of orange, white, red and brown clouds that cover the gas giant.

 

"We are not looking for trouble, we are looking for data," said Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio. "Problem is, at Jupiter, looking for the kind of data Juno is looking for, you have to go in the kind of neighborhoods where you could find trouble pretty quick."

 

The source of potential trouble can be found inside Jupiter itself. Well below the Jovian cloud tops is a layer of hydrogen under such incredible pressure it acts as an electrical conductor. Scientists believe that the combination of this metallic hydrogen along with Jupiter's fast rotation -- one day on Jupiter is only 10 hours long -- generates a powerful magnetic field that surrounds the planet with electrons, protons and ions traveling at nearly the speed of light. The endgame for any spacecraft that enters this doughnut-shaped field of high-energy particles is an encounter with the harshest radiation environment in the solar system.

 

"Over the life of the mission, Juno will be exposed to the equivalent of over 100 million dental X-rays," said Rick Nybakken, Juno's project manager from NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California. "But, we are ready. We designed an orbit around Jupiter that minimizes exposure to Jupiter’s harsh radiation environment. This orbit allows us to survive long enough to obtain the tantalizing science data that we have traveled so far to get.”

more at the link...

https://www.nasa.gov/press-release/nasa-s-juno-spacecraft-to-risk-jupiter-s-fireworks-for-science

 

[BetaguyGZT]

(I still can't get over that JOI video. Love how they did that one.)

 

Anyway, som'more sciencey stuff about Juno. That's what we all want.  

 

Juno Mission YouTube Channel | Juno's Scientific Instruments (Wikipedia) | Juno's Scientific Objectives (Wikipedia) | Juno's Journey to Jupiter (Video, WikiMedia)

 

Juno's approach, JOI maneuver, and planned Orbital Track. Image courtesy of NASA JPL - http://juno.wisc.edu

 

Things are gonna get busy pretty soon. Juno is already within the Jupiter system ... it's already passed the Himalia Group of Moons, and is making its' way toward Jupiter at a relative velocity of 13,000 mph -- last measured May 6th, according to the NASA Mission Site. It's 8.6 million miles (13.8 million kilometers) away from Jupiter as of midnight. Jupiter's getting fairly impressive-looking in the window by now, I bet ... and so are the radiation readings, too.

 

Next encounter should be an overhead view of the large moons, starting with Callisto. I expect some fantastic photo ops.  

 

[Draggendrop Veteran]

 

[DocM]

https://www.jpl.nasa.gov/news/news.php?feature=6896

 

The images were taken on July 10, 2017 at 07:07 p.m. PDT (10:07 p.m. EDT), as Juno executed its 7th close flyby of Jupiter. Taken from about 9,866 km (6,130 mi) from the top of the clouds.