juno launch press kit

8/6/2019 Juno Launch Press Kit

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Juno Launch

PRESS KIT/AUGUST 2011


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Juno Launch 2 Press Kit

Media Contacts

Dwayne Brown Policy/Program 202-358-1726

NASA Headquarters Management [email protected]

Washington

DC Agle Juno Mission 818-393-9011

Jet Propulsion [email protected]

Laboratory

Pasadena, Calif.

Maria Martinez Science Investigation 210-522-3305

Southwest Research Institute [email protected] Antonio

Gary Napier Spacecraft 303-971-4012

Lockheed Martin Space Systems [email protected]

Denver


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Contents

Media Services Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Quick Facts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Jupiter at a Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Why Juno? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Mission Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Mission Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Spacecraft. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Science Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Missions to Jupiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Program/Project Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24


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Media Services Information

NASA Television Transmission

The NASA TV Media Channel is available on an MPEG-2

digital C-band signal accessed via satellite AMC-6, at 72degrees west longitude, transponder 17C, 4040 MHz,vertical polarization. In Alaska and Hawaii, its availableon AMC-7 at 137 degrees west longitude, transpon-der 18C, at 4060 MHz, horizontal polarization. A Digital

Video Broadcast compliant Integrated Receiver Decoderis required or reception. For digital downlink inormationor NASA TVs Media Channel, access to NASA TVsPublic Channel on the Web and a schedule o program-ming or Juno activities, visit http://www.nasa.gov/ntv .

Media Credentialing

News media representatives who wish to cover the Junolaunch must contact NASA Kennedy Space CenterPublic Aairs in advance at: 321-867-2468.

Briefngs

A pre-launch news conerence will be held at theKennedy Space Center Press Site at 1 p.m. EDT on

Aug. 3, 2011. The news conerence will be televised onNASA TV.

Launch Status

Recorded status reports will be available beginning twodays beore launch at 321-867-2525 and 301-286-NEWS.

Internet Inormation

More inormation on the Juno mission, including anelectronic copy o this press kit, news releases, statusreports and images, can be ound at http://missionjuno.swri.edu/ and http://www.nasa.gov/juno/ .


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Quick Facts

Mission Name

The Juno spacecrat will, or the rst time, see below

Jupiters dense cover o clouds. This is why the mis-sion was named ater the Roman goddess, who wasJupiters wie, and who could also see through clouds.

Spacecrat

Dimensions: 11.5 eet (3.5 meters) high, 11.5 eet(3.5 meters) in diameter.

Solar Arrays: length o each solar array 29.5 eet (9 me-ters) by 8.7 eet (2.65 meters). Total surace area osolar arrays: more than 650-eet (60-meters) squared.

Total number o individual solar cells: 18,698. Totalpower output (Earth distance rom sun): approximately14 kilowatts; (Jupiter distance rom sun): approximately400 watts.

Weight: 7,992 pounds (3,625 kilograms) total at launch,consisting o 3,513 pounds (1,593 kilograms) o space-crat, 2,821 pounds (1,280 kilograms) o uel and1,658 pounds (752 kilograms) o oxidizer.

Launch Vehicle

Type: Atlas V551 (Atlas rst stage with ve solid rocketboosters, Centaur upper stage)

Height with payload: 197 eet (60 meters)

Mass ully ueled: 1,265,255 pounds (574,072 kilo-grams)

Juno Mission Milestones and Distances Traveled

Launch period: Aug. 526, 2011 (22 days)

Launch location: Pad SLC-41, Cape Canaveral Air ForceStation, Fla.

EarthJupiter distance at time o launch: 445 millionmiles (716 million kilometers)

Time it takes light to travel rom Earth to Jupiter onAug. 5, 2011: 39 minutes, 50 seconds

Earth gravity assist fyby: October 9, 2013

Distance Juno travels launch to Earth gravity assist:994 million miles (1,600 million kilometers)

Junos altitude over Earths surace at closest point dur-ing gravity assist: 311 miles (500 kilometers)

Jupiter arrival: July 4, 2016, 7:29 p.m. (PDT)

Distance o Jupiter to Earth at time o Jupiter orbit inser-tion: 540 million miles (869 million kilometers)

One-way speed-o-light time rom Jupiter to Earth in July2016: 48 minutes, 19 seconds

Total distance traveled, launch to Jupiter orbit insertion:

1,740 million miles (2,800 million kilometers)

End o mission (deorbit): October 16, 2017

Distance traveled in orbit around Jupiter: 348 millionmiles (560 million kilometers)

Total distance, launch through Jupiter impact: 2,106 mil-lion miles (3,390 million kilometers)

Program

The Juno mission investment is approximately $1.1 bil-lion in total. This cost includes spacecrat develop-ment, science instruments, launch services, missionoperations, science processing and relay support or74 months.


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Jupiter at a Glance

The largest and most massive o the planets wasnamed ater the king o the gods, called Zeus by theGreeks and Jupiter by the Romans; he was the mostimportant deity in both pantheons.

As the most massive inhabitant o our solar system,and with our large moons o its own and many smallermoons, Jupiter orms its own kind o miniature solarsystem. In act, Jupiter resembles a star in composi-tion, and i it had been about 80 times more massive, itwould have become a star rather than a planet.

Jupiters appearance is a tapestry o beautiul colorsand atmospheric eatures. Most visible clouds arecomposed o ammonia. Water clouds exist deep belowand can sometimes be seen through clear spots in theclouds. The planets stripes are created by strongeast-west winds in Jupiters upper atmosphere. Withinthese belts and zones are storm systems that can rageor years. The Great Red Spot, a giant spinning storm,has been observed or more than 300 years. In recentyears, three storms merged to orm the Little Red Spot,about hal the size o the Great Red Spot.

The composition o Jupiter is similar to that o the sun mostly hydrogen and helium. Deep in the atmosphere,the pressure and temperature increase, compressingthe hydrogen gas into a liquid. At depths o about a thirdo the way down, the hydrogen becomes a liquid thatconducts electricity like a metal. It is in this metallic layerthat scientists think Jupiters powerul magnetic eld isgenerated by electrical currents driven by Jupiters astrotation. At the center, the immense pressure may sup-port a core o heavy elements much larger than Earth.

Jupiters enormous magnetic eld is nearly 20,000times as powerul as Earths. Trapped within Jupitersmagnetosphere (the vast area o space that the planetsmagnetic eld dominates) are swarms o charged par-ticles. The magnetic eld traps some o these electronsand ions in an intense radiation belt that bathes Jupitersrings and moons. The Jovian magnetosphere, compris-ing these particles and elds, balloons 600,000 to 2 mil-lion miles (1 to 3 million kilometers) toward the sun and

I you take everything else in the solar system (not including the sun), it would all ft inside

Jupiter

tapers into a windsock-shaped tail extending more than600 million miles (1 billion kilometers) behind Jupiter, asar as Saturns orbit.

On Jan. 7, 1610, using his primitive telescope, astrono-mer Galileo Galilei saw our small stars near Jupiter.He had discovered Jupiters our largest moons, nowcalled Io, Europa, Ganymede and Callisto. These ourmoons are known today as the Galilean satellites. Notincluding the temporary moons, Jupiter has 64 con-rmed moons. (Temporary moons are comets that have

been temporarily captured by Jupiters massive gravityeld. These temporary satellites may circle Jupiter oryears beore continuing on their way through the solarsystem or burn up as they enter its atmosphere.) Jupiterhas three thin rings around its equator, which are muchainter than the rings o Saturn. Jupiters rings appear toconsist mostly o ne dust particles and may be ormedby dust kicked up as interplanetary meteoroids smashinto the giant planets our small inner moons. They werediscovered in 1979 by NASAs Voyager 1 spacecrat.

Signifcant Dates in Jovian History

1610: Galileo Galilei makes the rst detailedobservations o Jupiter.

1973: NASAs Pioneer 10 becomes the rstspacecrat to cross the asteroid belt and fypast Jupiter.

1979: NASAs Voyager 1 and 2 discoverJupiters aint rings, several new moons andvolcanic activity on Ios surace.

1994: Astronomers and NASAs Galileo space-crat observe as pieces o comet Shoemaker-Levy 9 collide with Jupiters southern hemi-sphere.

1995: The Galileo spacecrat and probe arriveat Jupiter to explore Jupiters atmospheredirectly or the rst time and to conduct anextended study o the giant planet system.


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Why Juno?

Jupiter is by ar the largest planet in the solar system.Humans have been studying it or hundreds o years,yet still many basic questions about the gas world

remain. In 1995, NASAs Galileo mission made the voy-age to Jupiter. One o its jobs was to drop a probe intoJupiters atmosphere. The data returned rom that probeshowed us that Jupiters composition was dierent thanscientists thought, indicating that our theories o plan-etary ormation were wrong. Today, there remain majorunanswered questions about this giant planet and theorigins o our solar system hidden beneath the cloudsand massive storms o Jupiters upper atmosphere.

How did Jupiter orm?

How much water or oxygen is in Jupiter?

What is the structure inside Jupiter?

Does Jupiter rotate as a solid body, or is the rotatinginterior made up o concentric cylinders?

Is there a solid core, and i so, how large is it?

How is its vast magnetic eld generated?

How are atmospheric eatures related to the move-ment o the deep interior?

What are the physical processes that power theauroras?

What do the poles look like?

Junos primary goal is to reveal the story o the ormationand evolution o the planet Jupiter. Using long-proventechnologies on a spinning spacecrat placed in an el-

liptical polar orbit, Juno will observe Jupiters gravity andmagnetic elds, atmospheric dynamics and composi-tion, and the coupling between the interior, atmosphereand magnetosphere that determines the planets prop-erties and drives its evolution. An understanding o theorigin and evolution o Jupiter, as the archetype o giantplanets, can provide the knowledge needed to help usunderstand the origin o our solar system and planetarysystems around other stars.


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The Juno spacecrat is scheduled to launch aboard anAtlas V551 rocket rom Cape Canaveral, Fla., in Aug.2011, reaching Jupiter in July 2016.

Following launch rom Cape Canaveral Air Force Station,Fla., the Juno spacecrat is scheduled to use its mainrocket motor twice (or an Aug. 5 launch, it would beused on Aug. 30, and Sept. 3, 2012) to modiy itstrajectory towards Jupiter. During cruise, there are also13 planned trajectory correction maneuvers to rene itsorbital path. An Earth fyby 26 months ater launch willprovide a boost o spacecrat velocity, placing it on atrajectory or Jupiter. The transit time to Jupiter ollowingthe Earth fyby is about three years, including the periodo the initial capture orbit. The 30-minute orbit insertion

burn will place Juno in orbit around Jupiter in early July2016.

Mission Overview

To accomplish its science objectives, Juno orbits overJupiters poles and passes very close to the planet.Juno needs to get extremely close to Jupiter to make

the very precise measurements the mission is ater. Thisorbital path carries the spacecrat repeatedly throughhazardous radiation belts but avoids the most power-ul radiation belts. Jupiters radiation belts are analogousto Earths Van Allen belts but ar more deadly.

The spacecrat will orbit Jupiter 33 times, skimming towithin 3,100 miles (5,000 kilometers) above the planetscloud tops every 11 days, or approximately one year.


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Mission Phases

Thirteen mission phas-es have been denedto describe the dier-ent periods o activityduring Junos travels.

These phases are:Pre-Launch, Launch,Inner Cruise 1, InnerCruise 2, Inner Cruise3, Quiet Cruise, Jupiter

Approach, JupiterOrbit Insertion, CaptureOrbit, Period ReductionManeuver, Orbit 1-2,

Science Orbits andDeorbit.

Pre-Launch Phase

The Flight System is mated to the launch vehicle at

L-10 days. Juno uses Space Launch Complex 41(SLC-41) at Cape Canaveral Air Force Station, thesame launch pad used by NASAs New Horizons mis-sion and other Atlas V launch vehicles.

The Pre-Launch mission phase lasts rom spacecratpower-up at L-3 days to nal spacecrat congurationat L-45 minutes. Junos launch period lasts 22 days(Aug. 526, 2011) with a launch window at least 60minutes in duration every day o the launch period. Thelaunch period has been optimized to maximize injectedmass into Jupiter science orbits.

5-mPayloadFairing

LaunchVehicleAdapterAtlas V Booster

Solid Rocket

Boosters

RD-180Engine

JunoSpacecraft

Centaur

Boattail

CentaurInterstageAdapterBooster

CylindricalInterstageAdapter

Forward Load

Reactor (FLR)

RL 10A CentaurEngine

The Atlas V551 is a two-

stage launch vehicle thatuses a standard Atlasbooster with ve solidrocket boosters in the rststage and a Centaur upperstage or the second. TheCentaur upper stage hasa restartable engine andis three-axis stabilized.Guidance and navigationare provided by the Centaurollowing launch. The Juno

spacecrat is enclosed orthe fight through Earthsatmosphere in the Atlass16.4-oot (5-meter) diam-eter, 68-oot (20.7-meter)long payload airing.

Launch Vehicle

Launch vehicle


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Boost Profle and Injection

The boost phase begins with the ignition o the boosterengine system. Lito occurs when the Atlass ve solidrocket boosters are ignited.

Upon burnout o the solid rocket boosters (at ap-

proximately 104 seconds ater launch) they are staggerjettisoned: rst solids 1 and 2, then 1.5 seconds later,solids 3, 4 and 5.

The launch vehicle is throttled to maintain 2.5 gs orPayload Fairing Jettison, which occurs a little underthree-and-a-hal minutes ater launch. Following jet-tison o the payload airing, acceleration is maintainedat 5.0 gs until booster engine cuto. The Atlas/Centaurseparation occurs approximately six seconds aterbooster engine cuto. The rst burn o the second stage

o the Centaur rocket begins 10 seconds ater the sepa-ration. The rst Centaur burn lasts about six minutesand completes when the vehicle has achieved its targetparking orbit.

Launch profle


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During the parking orbit coast period (approximately30 minutes in length), the Centaur turns itsel and thespacecrat to the required attitude or the start o itssecond burn. The Centaurs second burn (approximate-ly nine minutes in length) places Juno on the desireddeparture trajectory.

Following the completion o its second burn, theCentaur turns to a pre-planned separation attitude andinitiates a 1.4 revolutions per minute roll rate. The Junospacecrat is scheduled to separate rom its Centaurbooster about three-and-a-hal minutes ater theCentaur completes its burn. At the time o separation,a clampband releases and push-o springs push the

Juno spacecrat rom the Centaur.

Solar Array Deployment

Junos massive solar arrays are scheduled to begin de-ployment about ve minutes ollowing separation. Thelength o time it takes or deployment is expected to beless than three minutes.

Transition to the Cruise mission phase is expected tooccur three days ater launch.

Cruise Phases

Junos trajectory to Jupiter consists o ve phases over

ve years and one-and-a-hal loops o the sun.

There are our cruise phases: Inner Cruise 1 (61 days),Inner Cruise 2 (598 days), Inner Cruise 3 (161 days), andQuiet Cruise (791 days).

During cruise, the spacecrat is usually oriented so thatits high-gain antenna is Earth-pointed. However, closeto the sun there are times where thermal and powerrequirements do not allow or Earth-pointing o the an-tenna. At these times the spacecrat is pointed o-sunin such a way that thermal requirements can be met.

Inner Cruise Phase 1

The Inner Cruise 1 phase spans the interval rom L+3 toL+63 days. It is characterized by initial spacecrat andinstrument checkouts, deployment o the Waves instru-ment antenna, Junos rst trajectory correction maneu-ver, and the location o the spacecrat ar enough romthe sun to allow Earth-pointing instead o sun-pointing. EarthJupiter trajectory

Solar array deployment sequence


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The Inner Cruise 2 phase spans the period rom L+63days until L+661 days (1.6 years in length). The mis-sions two deep space maneuvers occur during thisphase, prior to the spacecrats one Earth fyby. Otherspacecrat activities during the Inner Cruise 2 phase in-

clude calibrations and alignments associated with usingthe high-gain antenna or the rst time. The spacecratsscience instruments are also checked out again.


The Inner Cruise 3 phase spans the interval rom L+661days to L+822 days. During this time, the Juno fightteam is ocused on perorming the required maneuvers,as well as an integrated operations exercise aroundEarth fyby.

The Earth fyby occurs as the spacecrat is completingone elliptical orbit around the sun. It will boost Junosvelocity by 16,330 miles per hour (about 7.3 kilometersper second), placing the spacecrat on its nal trajectoryor Jupiter. Closest approach to Earth occurs on Oct. 9,2013, at an altitude o 310 miles (500 kilometers). Theexact time o closest approach will vary by about eighthours on this date, depending on launch date.

During the fyby, Juno will pass behind Earth as seenrom the sun, causing an interval when Earth blocks the

suns rays rom reaching the spacecrats solar panels,The time in eclipse is about 20 minutes, and representsthe only time ater Launch Phase when Juno will notreceive direct sunlight.

Three trajectory correction maneuvers are planned be-ore and one ater Earth fyby to rene Junos trajectory.

Quiet Cruise Phase

The Quiet Cruise phase lasts rom L+822 days untilthe start o Jupiter Approach at L+1,613 days. During

the tail end o the Quiet Cruise phase, which lasts or26 months, the Juno project team will be staed up tolevels anticipated as needed or upcoming operationsaround Jupiter.

Jupiter Approach Phase

The Jupiter Approach phase lasts the nal six monthso cruise (178 days) beore Jupiter Orbit Insertion. The

phase ends at Jupiter Orbit Insertion minus our days,which is the start o the critical sequence that will resultin the spacecrat orbiting Jupiter.

This phase is characterized by instrument checkouts aswell as initial science observations o Jupiter. Calibrationsand science observations perormed during this phase

go a long way toward validating instrument perormancein the Jupiter environment, testing the data processingpipeline, and preparing the team or successully return-ing baseline Jupiter science data starting in Orbit 3.

Jupiter Orbit Insertion Phase

The Jupiter Orbit Insertion phase begins our daysbeore the start o the orbit insertion maneuver and endsone hour ater the start o the insertion maneuver. JupiterOrbit Insertion occurs at closest approach to Jupiter,and slows the spacecrat enough to let it be captured by

Jupiter into a 107-day-long orbit. The insertion maneu-ver also sets up the orbital geometry or uture 11-dayscience orbits.

The Jupiter Orbit Insertion burn is perormed on themain engine (the third large main engine burn o themission). The burn will last 30 minutes and is designedto be perormed in view o Earth. Ater the burn, thespacecrat is in a polar orbit around Jupiter.

Capture Orbit Phase

The Capture Orbit phase starts at Jupiter Orbit Insertionplus one hour and ends 18 hours beore the PeriodReduction Maneuver 106 days later. The 107-dayCapture Orbit provides substantial propellant savingswith respect to a direct Jupiter Orbit Insertion entry intoan 11-day orbit.

A cleanup maneuver 7.6 days ater the beginning othis phase is perormed to ensure the timing o the largeburn in the upcoming phase. Instruments are on ormost o the Capture Orbit, and there are routine check-

outs and science observations.

The Capture Orbit is an opportunity to gain valuableearly orbital operations experience with the spacecratas well as the instruments. The team plans to have allthe instruments on and taking data beginning 50 hoursater Jupiter Orbit Insertion.


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As with Jupiter Approach observations, calibrations andscience observations perormed during the CaptureOrbit go a long way toward validating instrument peror-mance in the Jupiter Environment.

Period Reduction Maneuver Phase

During the Period Reduction Maneuver phase, Junotransitions rom an orbit that takes 107 days to cir-cumnavigate Jupiter to one that takes only 11 days.

The phase starts 18 hours beore the maneuver andconcludes 11 hours ater the maneuver is complete.

The rocket ring that takes place during this maneuveris a larger burn in duration (37 minutes) than the JupiterOrbit Insertion burn. The Period Reduction Maneuverburn is perormed on the main engine (the ourth andlast large main engine burn o the mission). No scienceobservations are planned during this phase.

Orbits 12 Phase

The Orbits 12 phase starts 11 hours ater the PeriodReduction Maneuver burn near the beginning o therst 11-day orbit. This phase ends 20 days later withthe commencement o the missions rst science orbit.

Orbit 2 and Planned Science

In addition to calibrations and other instrument prepara-tions or the science orbits, preliminary Orbit 2 scienceplans include: remote sensing movies and atmosphericdynamics measurements, water abundance observa-tions and elds and particles observations like thoseplanned or the science orbits.

Science Orbits Phase

The Science Orbits phase includes Orbit 3 throughOrbit 33 and lasts 336 days. Small orbital trim maneu-vers are planned about our hours ater each set operijove (closest approach to Jupiter) science observa-tions. These maneuvers target the longitude required

or science observations in the next orbit.

Junos Highly Elliptical Polar Orbits

Orbiting Jupiter around the poles carries Juno repeated-ly over every latitude. As the planet rotates beneath thespacecrat, the entire surace can be covered by Junossuite o instruments.

For many o the instruments to do their job, the space-crat has to get closer to Jupiter than any previous mis-sion. To avoid the highest levels o radiation in the beltssurrounding Jupiter, mission navigators have designeda highly elongated orbit that approaches the gas giantrom the north. Flying south, the spacecrats point oclosest approach will be about 3,100 miles (5,000 ki-lometers) above the cloud tops. As Juno exits over thesouth pole, its orbit carries it ar beyond even the Jovianmoon Callistos orbit.

Junos elliptical orbit around Jupiter has another benet.

It allows the spacecrats three massive solar panels tobe constantly bathed in sunlight. This is important be-cause the amount o sunlight that reaches Jupiter is only1/25th that which reaches Earth. To keep the space-crats instruments and operating systems poweredrequires the solar panels to have an almost constantexposure to the available sunlight.

Deorbit Phase

The Deorbit phase occurs during the nal orbit o the

mission. The 5.5-day phase starts several days ater theOrbit 33 science pass and ends with impact into Jupiterduring the ollowing orbit.

The deorbit maneuver was designed to satisy NASAsplanetary protection requirements and ensure that Junodoes not impact Europa (as well as Ganymede andCallisto).

By orbit 34, a deorbit burn will be executed, placing thespacecrat on a trajectory that will reset its point o clos-est approach to the planet to an altitude that is below

the cloud tops at 34 degrees North Jupiter latitude onOct. 16, 2017. Juno is not designed to operate insidean atmosphere and will burn up.


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Spacecraft

Juno uses a spinning, solar-powered spacecrat in ahighly elliptical polar orbit that avoids most o Jupitershigh-radiation regions. The designs o the individual

instruments are straightorward and the mission did notrequire the development o any new technologies.

Why A Rotating Spacecrat?

For Juno, like NASAs earlier Pioneer spacecrat, spin-ning makes the spacecrats pointing extremely stableand easy to control. Just ater launch, and beore itssolar arrays are deployed, Juno will be spun-up byrocket motors on its still-attached second-stage rocketbooster. Junos planned spin rate varies during the mis-sion: 1 RPM or cruise, 2 RPM or science operations

and 5 RPM or main engine maneuvers.

To simpliy and decrease weight, all instruments arexed. While in orbit at Jupiter, the spinning spacecratwill sweep the elds o view o its instruments throughspace once or each rotation. At two rotations per min-ute, the instruments elds o view sweep across Jupiterabout 400 times in the two hours it takes Juno to fyrom pole to pole.

Structure

The spacecrats main body measures 11.5 eet(3.5 meters) tall and 11.5 eet (3.5 meters) in diameter.

The spacecrats hexagonal two-deck structure usescomposite panel and clip construction or decks, centralcylinder and gusset panels. Polar mounted o-centerspherical tanks provide spinning spacecrat designs withhigh stability.

Propulsion System

For weight savings and redundancy, Juno uses a dual-

mode propulsion subsystem, with a bi-propellant mainengine and mono-propellant reaction control systemthrusters.

The Leros-1b main engine is a 645-Newton bi-pro-pellant thruster using hydrazinenitrogen tetroxide.Its engine bell is enclosed in a micrometeoroid shieldthat opens or engine burns. The engine is xed to thespacecrat body ring at and is used or major maneu-vers and fushing burns.

The 12 reaction control system thrusters are mountedon our rocket engine modules. They allow translationand rotation about three axes. They are also used or

most trajectory correction maneuvers.

Command and Data Handling

Command and data handling includes a RAD750 fightprocessor with 256 megabytes o fash memory and128 megabytes o DRAM local memory. It provides100 Mbps total instrument throughput, more thanenough or payload requirements.

Electronics Vault

To protect sensitive spacecrat electronics, Juno willcarry the rst-o-its-kind radiation shielded electronicsvault, a critical eature or enabling sustained explorationin such a heavy radiation environment. Each o the tita-nium cubes eight sides measures nearly a square meter(nearly 9 square eet) in area, about a third o an inch(1 centimeter) in thickness, and 4 pounds (18 kilograms)in mass. This titanium box about the size o an SUVstrunk encloses Junos command and data handlingbox (the spacecrats brain), power and data distributionunit (its heart) and about 20 other electronic assemblies.

The whole vault weighs about 500 pounds (200 kilo-grams).

Power

Junos Electrical Power Subsystem manages the space-crat power bus and distribution o power to payloads,propulsion, heaters and avionics. The power distributionand drive unit monitors and manages the spacecratpower bus, manages the available solar array power tomeet the spacecrat load and battery state o charge,and provides controlled power distribution.

Power generation is provided by three solar arraysconsisting o 11 solar panels and one MAG boom. Two55 amp-hour lithium-ion batteries provide power whenJuno is o-sun or in eclipse, and are tolerant o theJupiter radiation environment. The power modes duringscience orbits are sized or either data collection duringan orbit emphasizing microwave radiometry or gravityscience.


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Solar Power

Jupiters orbit is ve times arther rom the sun thanEarths, so the giant planet receives 25 times lesssunlight than Earth. Juno will be the rst solar-poweredspacecrat designed to operate at such a great distancerom the sun, thus the surace area o solar panels re-

quired to generate adequate power is quite large.

Juno benets rom advances in solar cell design withmodern cells that are 50 percent more ecient andradiation-tolerant than silicon cells available or spacemissions 20 years ago. The missions power needs aremodest. Juno has energy-ecient science instruments.Solar power is possible on Juno due to the energy-ecient instruments and spacecrat, a mission designthat can avoid Jupiters shadow and a polar orbit thatminimizes the total radiation.

The spacecrats three solar panels extend outwardrom Junos hexagonal body, giving the overall space-crat a span o more than 66 eet (20 meters). The solarpanels will remain in sunlight continuously rom launchthrough end o mission, except or a ew minutes dur-ing the Earth fyby. Beore deployment in space, thesolar panels are olded into our-hinged segments sothe spacecrat can t into the launch vehicles payloadairing.

Thermal Control

Junos thermal control subsystem uses a passive de-sign with heaters and louvers. The main component othe thermal control subsystem consists o an insulated,louvered electronics vault atop an insulated, heated pro-pulsion module. This design accommodates all mission

thermal environments rom Earth orbit to Jupiter orbitaloperations. During cruise, while the spacecrat is closeto the sun, the high-gain antenna is used as a heatshield to protect the vault avionics.

Most instrument electronics are contained within theradiation vault and are thermally managed as part o thevault thermal control system. Science sensors are exter-nally mounted to the deck and are individually blanketedand heated to maintain individual temperature limits.

Science Instruments

The Juno spacecrat carries a payload o 29 sensors,which eed data to nine onboard instruments. Eighto these instruments (MAG, MWR, Gravity Science,Waves, JEDI, JADE, UVS, JIRAM) are considered thescience payload. One instrument, JunoCam, is aboardto generate images or education and public outreach.

Primary science observations are obtained within three

hours o closest approach to Jupiter, although calibra-tions, occasional remote sensing and magnetosphericscience observations are planned throughout the sci-ence orbits around Jupiter.

Juno is spin-stabilized. Because o the spacecrat mis-sion design and the act that its science instrumentswere all developed together, and there is no need or ascan platorm to point instruments in dierent directions.Gravity science and microwave sounding o the atmo-sphere observations are obtained through orientation othe spacecrats spin plane. All other experiments utilizeride-along pointing and work in either one or both orien-tations. This design allows or very simple operations.

Telecommunications

The gravity science and telecom subsystem providesX-band command uplink and engineering telemetry andscience data downlink or the entire post-launch, cruiseand Jupiter orbital operations. The subsystem also pro-vides or dual-band (X- and Ka-band) Doppler trackingor gravity science at Jupiter.


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Juno spacecrat

Gravity Science

The Gravity Science experiment will enable Juno

to measure Jupiters gravitational feld and reveal

the planets internal structure.

Two transponders operating on dierent requencies(Ka- and X-band) will detect signals sent rom NASAsDeep Space Network on Earth and immediately sendsignals in return. Small changes in the signals requen-cies (as they are received on Earth) provide data onhow much Junos velocity has been modied due tolocal variations in Jupiters gravity. These subtle shits in

Junos velocity reveal the gas giants gravity (and howthe planet is arranged on the inside), and provide insightinto the gas giants internal structure.

Agenzia Spaziale Italiana in Rome, Italy contributed theKa-band translator system.

Magnetometer (MAG)

Junos Magnetometer creates a detailed three-

dimensional map o Jupiters magnetic feld.

Junos Magnetometer instrument is a fux gate typemagnetometer, which measures the strength and direc-tion o Jupiters magnetic eld lines. An Advanced StellarCompass images stars to provide inormation on theexact orientation o the magnetometer sensors. This en-ables Junos very precise magnetic eld measurement.Magnetometer sensors are mounted on the magnetom-eter boom at the end o one o Junos three solar arrays

as ar away rom the spacecrat body as possible.This was done to avoid the instruments rom conusingthe spacecrat magnetic eld with Jupiters. The boomis designed to mimic the outermost solar array panel (othe remaining two solar array structures) in mass andmechanical deployment.

The spacecrat magnetic eld is urther separated romJupiters eld by the use o two magnetometer sen-


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Magnetometer

sors one 33 eet (10 meters) rom the center o thespacecrat and one 39 eet (12 meters) rom the center.By comparing measurements rom both sensors, scien-tists can isolate the magnetic eld o Juno rom Jupiter.

The Flux Gate Magnetometer was designed and built

Microwave Radiometer (MWR)

Junos Microwave Radiometer instrument will

probe beneath Jupiters cloud tops to provide data

on the structure, movement and chemical compo-

sition to a depth as great as 1,000 atmospheres

about 342 miles (550 kilometers) below the visible

cloud tops.

The Microwave Radiometer consists o six radiometersdesigned to measure the microwaves coming rom sixcloud levels. Each o the six radiometers has an antennaextending rom Junos hexagonal body. Each antennais connected by a cable to a receiver, which sits in theinstrument vault on top o the spacecrat. NASAs JetPropulsion Laboratory in Pasadena, Cali. provided theMicrowave Radiometer subsystem components, includ-ing the antennas and receivers.

by NASAs Goddard Space Flight Center Greenbelt,Md., and the Advanced Stellar Compass was designedand built by the Danish Technical University in Lyngby,Denmark.

Jupiter Energetic Particle Detector Instrument

(JEDI)

The Jupiter Energetic Particle Detector

Instrument will measure the energetic particles

that stream through space and study how they

interact with Jupiters magnetic feld.

JEDI comprises three identical sensor units each with6 ion and 6 electron views. The instrument works incoordination with the JADE and Waves instruments toinvestigate Jupiters polar space environment, with aparticular ocus on the physics o Jupiters intense andimpressive northern and southern auroral lights.

The instrument was designed and built by the JohnsHopkins Universitys Applied Physics Laboratory, Laurel,Md.


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between the auroras, the streaming particles that

create them and the magnetosphere as a whole.

The Ultraviolet Imaging Spectrograph instrument con-sists o two separate sections: a dedicated telescope/spectrograph assembly and a vault electronics box. Thetelescope/spectrograph assembly contains a telescope

which ocuses collected light into a spectrograph. Theinstruments electronics box is located in Junos radia-tion-shielded spacecrat vault.

The Ultraviolet Imaging Spectrograph instrument wasdesigned and built by Southwest Research Institute inSan Antonio.

Jovian Inrared Auroral Mapper (JIRAM)

The Jovian Inrared Auroral Mapper will study

Jupiters atmosphere in and around the auro-

ras, helping us learn more about the interactions

between the auroras, the magnetic feld and the

magnetosphere. JIRAM will be able to probe the

atmosphere down to 30 to 45 miles (50 to 70 kilo-

meters) below the cloud tops, where the pressure

is fve to seven times greater than on Earth at sea

level.

The Jovian Inrared Auroral Mapper instrument consistso a camera and a spectrometer, which splits light into

its component wavelengths, like a prism. The camerawill take pictures in inrared light, which is heat radia-tion, with wavelengths o two to ve microns (millionthso a meter) three to seven times longer than visiblewavelengths.

The Jovian Inrared Auroral Mapper instrument wasdesigned and built by the Italian National Institute or

Astrophysics, Milano, Italy, and unded by the AgenziaSpaziale Italiana in Rome.

JunoCam

JunoCam will capture color pictures o Jupiters

cloud tops in visible light.

JunoCam will provide a wide-angle view o Jupitersatmosphere and poles. JunoCam is designed as anoutreach ull-color camera to engage the public. Thepublic will be involved in developing the images rom raw

Jovian Auroral Distributions Experiment (JADE)

The Jovian Auroral Distributions Experiment will

work with some o Junos other instruments to

identiy the particles and processes that produce

Jupiters stunning auroras.

The Jovian Auroral Distributions Experiment consists oan electronics box shared by our sensors: three will de-tect the electrons that surround the spacecrat ,and theourth will identiy positively charged hydrogen, helium,oxygen and sulur ions. When Juno fies directly overauroras, the instrument will be able to characterize theparticles that are coming down Jupiters magnetic eldlines and crashing into Jupiters atmosphere.

The Jovian Auroral Distributions Experiment was de-signed and built by the Southwest Research Institute inSan Antonio.

Waves

The Waves instrument will measure radio and

plasma waves in Jupiters magnetosphere, help-

ing us understand the interactions between the

magnetic feld, the atmosphere and the magneto-

sphere.

The Waves instrument consists o a V-shaped antennathat is about 13 eet (our meters) rom tip to tip, similar

to the rabbit-ear antennas that were once common onTVs. One o the ears o the Waves instrument detectsthe electric component o radio and plasma waves,while the other is sensitive to the magnetic component.

The magnetic antenna called a magnetic searchcoil consists o a coil o ne wire wrapped 10,000times around a 5.9-inch (15-centimeter) long core. Thesearch coil measures magnetic fuctuations in the audiorequency range.

The Waves instrument was designed and built by theUniversity o Iowa in Iowa City.

Ultraviolet Imaging Spectrograph (UVS)

The Ultraviolet Imaging Spectrograph will take

pictures o Jupiters auroras in ultraviolet light.

Working with Junos JADE and JEDI instruments,

which measure the particles that create the auro-

ras, UVS will help us understand the relationship


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data and even helping to design which areas o Jupitershould be imaged.

The JunoCam camera head has a lens with a 58-de-gree cross-scan eld o view. It acquires images bysweeping out that eld while the spacecrat spins tocover an along-scan eld o view o 360 degrees. Lines

containing dark sky are subsequently compressed toan insignicant data volume. It takes images mainlywhen Juno is very close to Jupiter, with a maximumresolution o up to 1 to 2 miles (2 to 3 kilometers) per

pixel. The wide-angle camera will provide new views oJupiters atmosphere.

JunoCams hardware is based on a descent cam-era that was developed or NASAs Mars ScienceLaboratory rover. Some o its sotware was origi-nally developed or NASAs Mars Odyssey and Mars

Reconnaissance Orbiter spacecrat. JunoCam isprovided by Malin Space Science Systems, San Diego.Cali.


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Science Overview

The Giant Planet Story is the Story o the Solar System

The principal goal o NASAs Juno mission is to under-

stand the origin and evolution o Jupiter. Underneath itsdense cloud cover, Jupiter saeguards secrets to theundamental processes and conditions that governedour solar system during its ormation. As our primaryexample o a giant planet, Jupiter can also provide criti-cal knowledge or understanding the planetary systemsbeing discovered around other stars.

With its suite o science instruments, Juno will in-vestigate the existence o a possible solid planetarycore, map Jupiters intense magnetic eld, measurethe amount o water and ammonia in the deep atmo-

sphere, and observe the planets auroras.

Juno will let us take a giant step orward in our under-standing o how giant planets orm and the role thesetitans played in putting together the rest o the solarsystem.

Jupiters Origins and Interior

Theories about solar system ormation all begin withthe collapse o a giant cloud o gas and dust, or nebula,

most o which ormed the inant sun, our star. Like thesun, Jupiter is mostly hydrogen and helium, so it musthave ormed early, capturing most o the material let a-ter our star came to be. How this happened, however,is unclear. Did a massive planetary core orm rst andcapture all that gas gravitationally, or did an unstableregion collapse inside the nebula, triggering the planetsormation? Dierences between these scenarios areproound.

Even more importantly, the composition and role o icyplanetesimals, or small protoplanets, in planetary orma-

tion hangs in the balance and with them, the origino Earth and other terrestrial planets. Icy planetesimalslikely were the carriers o materials like water andcarbon compounds that are the undamental buildingblocks o lie.

Unlike Earth, Jupiters giant mass allowed it to holdonto its original composition, providing us with a wayo tracing our solar systems history. Juno will measurethe amount o water and ammonia in Jupiters atmo-

sphere and help determine i the planet has a core oheavy elements, constraining models on the origin othis giant planet and thereby the solar system. By map-

ping Jupiters gravitational and magnetic elds, Juno willreveal the planets interior structure and measure themass o the core.

Atmosphere

How deep Jupiters colorul zones, belts and othereatures penetrate is one o the most outstandingundamental questions about the giant planet. Junowill determine the global structure and motions o theplanets atmosphere below the cloud tops or the rsttime, mapping variations in the atmospheres composi-

tion, temperature, clouds and patterns o movementdown to unprecedented depths.

Magnetosphere

Deep in Jupiters atmosphere, under great pressure,hydrogen gas is squeezed into a fuid known as metallichydrogen. At these enormous pressures, the hydro-gen acts like an electrically conducting metal, which isbelieved to be the source o the planets intense mag-netic eld. This powerul magnetic environment createsthe brightest auroras in our solar system, as chargedparticles precipitate down into the planets atmosphere.Juno will directly sample the charged particles andmagnetic elds near Jupiters poles or the rst time,while simultaneously observing the auroras in ultravioletlight produced by the extraordinary amounts o energycrashing into the polar regions. These investigations willgreatly improve our understanding o this remarkablephenomenon, and also o similar magnetic objects, likeyoung stars with their own planetary systems.

Juno Science Objectives

The primary science objectives o the mission are asollows:

Origin

Determine the abundance o water and place an up-per limit on the mass o Jupiters possible solid core todecide which theory o the planets origin is correct


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Interior

Understand Jupiters interior structure and how materialmoves deep within the planet by mapping its gravita-tional and magnetic elds

Atmosphere

Map variations in atmospheric composition, tempera-

ture, cloud opacity and dynamics to depths greaterthan 100 bars at all latitudes.

Magnetosphere

Characterize and explore the three-dimensional struc-ture o Jupiters polar magnetosphere and auroras

The overall goal o the Juno mission is to improve ourunderstanding o the solar system by understanding theorigin and evolution o Jupiter. It addresses science ob-

jectives central to three NASA Science divisions: SolarSystem (Planetary), EarthSun System (Heliophysics),and Universe (Astrophysics).

Junos primary science goal o understanding theormation, evolution, and structure o Jupiter is directly

related to the conditions in the early solar system, whichled to the ormation o our planetary system. The masso Jupiters possible solid core and the abundance oheavy elements in the atmosphere discriminate amongmodels or giant planet ormation. Juno constrains thecore mass by mapping the gravitational eld, and mea-sures through microwave sounding the global abun-

dances o oxygen (water) and nitrogen (ammonia).

Juno reveals the history o Jupiter by mapping the gravi-tational and magnetic elds with sucient resolution toconstrain Jupiters interior structure, the source region othe magnetic eld, and the nature o deep convection.By sounding deep into Jupiters atmosphere, Juno de-termines to what depth the belts and zones penetrate.Juno provides the rst survey and exploration o thethree-dimensional structure o Jupiters polar magneto-sphere.


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Missions to Jupiter

Since 1972, Jupiter has been a port-o-call or nal desti-nation or eight NASA missions.

Pioneer 10

Launch: March 2, 1972Jupiter fyby: December 3, 1973

NASAs Pioneer 10 was the rst spacecrat to passthrough the Asteroid Belt and explore Jupiter. It fewwithin 124,000 miles (200,000 kilometers) o the Joviancloud tops. Scientists were surprised at the tremen-dous radiation levels experienced by the spacecrat as itpassed the gas giant planet.

Pioneer 11

Launch: April 5, 1973Jupiter fyby: December 2, 1974

Pioneer 11 few within 21,100 miles (34,000 kilometers)o the Jovian cloud tops. The spacecrat studied theplanets magnetic eld and atmosphere and took pic-tures o the planet and some o its moons.

Voyager 1

Launch: September 5, 1977Jupiter encounter: January 4 to April 13, 1979

Launched 16 days ater Voyager 2, Voyager 1 was onthe ast track to Jupiter and actually arrived our monthsahead o the other spacecrat. Voyager 1 few by Jupiteron March 5, 1979, taking more than 18,000 images oplanet and its moons.

Voyager 2

Launch: August 20, 1977Jupiter encounter: April 25 to August 5, 1979

Voyager 2 few by Jupiter on July 9, 1979, and took ap-

proximately 18,000 images o Jupiter and its moons.

Galileo

Launch: October 18, 1989Jupiter probe descent: December 7, 1995Jupiter orbit insertion: December 8, 1995Plunge into Jupiter: September 22, 2003

Galileo was the rst spacecrat to dwell in a giant planetsmagnetosphere long enough to identiy its global struc-

ture and investigate the dynamics o Jupiters magneticeld. It revealed that Jupiter had a ring system. Galileowas the rst spacecrat to deploy a probe into an outer

planets atmosphere. The spacecrats mission wasextended three times in order to study the Galileansatellites Io, Europa, Ganymede and Callisto.

To avoid any possibility o the spacecrat contaminat-ing any o Jupiters moons, upon completion o its thirdmission extension, Galileo was deliberately sent into theplanets atmosphere, where it burned up.

Ulysses

Launch: October 6, 1990

Jupiter fyby: February 8, 1992

Ulysses mission was to study the north and south poleo the sun. To get into an orbit that would take it overthe suns poles, Ulysses used the strong Jovian grav-ity to bend its trajectory. As Ulysses few by the planet,instruments onboard the spacecrat studied Jupitersstrong magnetic eld and radiation levels.

CassiniHuygens

Launch: October 15, 1997Jupiter fyby: December 30, 2000

CassiniHuygens orbital path to Saturn required fybyso Venus, Earth and Jupiter. The Cassini mission teamused its encounter with Jupiter to test the spacecratsinstruments and operations.

New Horizons

Launch: January 19, 2006Jupiter fyby: JanuaryMay, 2007

New Horizons used Jupiters massive gravity to placeit on a trajectory or Pluto. Beginning in early 2007, the

spacecrat observed Jupiter over ve months. Date oits closest approach with Jupiter was on February 28,2007.


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Program/Project Management

NASAs New Frontiers Program

The Juno mission is the second spacecrat designedunder NASAs New Frontiers Program. The rst wasthe Pluto New Horizons mission, launched in January2006 and scheduled to reach Plutos moon Charonin 2015. The third mission will be the Origins-SpectralInterpretation-Resource Identication-Security-RegolithExplorer, or OSIRIS-Rex the rst U.S. mission to

carry materials rom an asteroid back to Earth. Theprogram provides opportunities to carry out medium-

class missions identied as top priority objectives in theDecadal Solar System Exploration Survey, conductedby the Space Studies Board o the National ResearchCouncil in Washington.

More inormation is online at http://newrontiers.nasa.gov/program_plan.html .

Junos principal investigator is Scott Bolton o Southwest Research Institute in San Antonio. Steve Levin oNASAs Jet Propulsion Laboratory, Pasadena, Cali., is project scientist.

NASAs Jet Propulsion Laboratory, Pasadena, Cali., manages the Juno mission or the principal inves-tigator. The Juno mission is part o the New Frontiers Program managed at NASAs Marshall SpaceFlight Center in Huntsville, Ala. Lockheed Martin Space Systems, Denver, built the spacecrat. Launchmanagement or the mission is the responsibility o NASAs Launch Services Program at the KennedySpace Center in Florida. JPL is a division o the Caliornia Institute o Technology in Pasadena. At NASAHeadquarters, Ed Weiler is associate administrator or the Science Mission Directorate. Jim Green isdirector o the Planetary Science Division. Dennon Clardy is the manager o the Discovery/New FrontiersProgram oce, Adrianna OCampo is Juno program executive, and Mary Mellot is Juno program scientist.

At JPL, Jan Chodas is project manager. Rick Nybakken is deputy project manager.

Lockheed Martin Space Systems in Denver designed and built Juno and will handle its day-to-day opera-tions. Tim Gasparrini is the companys Juno program manager and leads the Juno fight team. The UnitedLaunch Alliance is responsible or the Atlas V rocket that will carry Juno into space.

More inormation about Juno is online at http://www.nasa.gov/juno and http://missionjuno.swri.edu .


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Juno Science Team

Scott Bolton, principal investigator,Southwest Research Institute, San Antonio

John Connerney, deputy principal investigator,Goddard Space Flight Center, Greenbelt, Md.

Steve Levin, project scientist,NASAs Jet Propulsion Laboratory, Pasadena, Cali.

Instrument Leads

Michael Janssen MWR Instrument Lead,Jet Propulsion Laboratory

John Connerney MAG Instrument Lead,Goddard Space Flight Center

David McComas JADE Instrument Lead,Southwest Research Institute

William Folkner Gravity Science Investigation Lead,Jet Propulsion Laboratory

Barry Mauk JEDI Instrument Lead,Johns Hopkins University/Applied Physics Laboratory

William Kurth Waves Instrument Lead, Univ. o Iowa

Randy Gladstone UVS Instrument Lead,

Southwest Research InstituteMichael Ravine JunoCam Instrument Lead,Malin Space Science Systems

Angioletta Coradini JIRAM Instrument Lead,Italian Space Agency

Co-Investigators

Michael Allison Goddard Space Flight Center

John Anderson Jet Propulsion Laboratory

Sushil Atreya University o Michigan

Fran Bagenal University o Colorado

Michel Blanc LObservatoire Midi Pyrnes

Jeremy Bloxham Harvard University

Stanley Cowley University o Leicester

Eric DeJong Jet Propulsion Laboratory

Daniel Gautier LESIA Observatoire de Paris

Tristan Guillot Observatoire de la Cote dAzur

Samuel Gulkis Jet Propulsion Laboratory

Candice Hansen Planetary Science Institute

William Hubbard University o Arizona

Andrew Ingersoll Caliornia Institute o Technology

Jonathan Lunine University o Arizona

Toby Owen University o Hawaii

Ed Smith Jet Propulsion Laboratory

Paul Stees Georgia Tech

David Stevenson Caliornia Institute oTechnology

Ed Stone Caliornia Institute oTechnology

Richard Thorne University o Caliornia LosAngeles

juno launch press kit

Documents