The majority of the text in this file was extracted from the JunoMission Plan Document, S. Stephens, 2012. [JPL D-35556]  Instrument Host Overview  =========================For most Juno experiments, data were collected by instruments onthe spacecraft then relayed via the orbiter telemetry system to stations ofthe NASA Deep Space Network (DSN).  Radio Science required the DSN for itsdata acquisition on the ground.  The following sections provide anoverview, first of the orbiter, then the science instruments, andfinally the DSN ground system.  Instrument Host Overview - Spacecraft  =======================================Juno launched on 5 August 2011.  The spacecraft uses a deltaV- Earth GravityAssist (EGA) trajectory consisting of a two part deep space maneuver on30 August and 3 September 2012 followed by an Earth gravity assist on9 October 2013 at an altitude of 500km.  Jupiter arrival was on 5 July 2016using a 107-day capture orbit prior to commencing operations for a1-(Earth) year long prime mission comprising 32 high inclination, higheccentricity orbits of Jupiter.  The initial orbit was polar (90 degreeinclination) with a periapsis altitude of 4500 km  and a semi-major axis of19.91 RJ (Jovian radius) giving an orbital period of 10.9725 days.  Theprimary science is acquired for approximately 6 hours centered on eachperiapsis although fields and particles data are acquired at low rates forthe remaining apoapsis portion of each orbit.Juno is a spin-stabilized spacecraft equipped for 8 diverse scienceinvestigations plus a camera included for education and public outreach.The spacecraft includes one high gain antenna (HGA), two low gainantennas (LGAs), a toroidal medium gain antenna, a large set of solar arraysin three 'wings', a main engine, and attitude thrusters.  In this descriptionJuno will frequently be called 'the spacecraft.'   Spacecraft Description   ===================Juno is spin-stabilized with a large spin-to-transverse moment ofinertia ratio.  It is solar powered with 3 large, deployable rigid-panelwings that can be moved to adjust the spin axis to the HGA boresight.The solar panels are spaced at 120 deg. intervals around a basic6-sided structure. Juno utilizes high energy density Li ionbatteries for battery-regulated bus voltage.  Basic radiationprotection for sensitive electronics is afforded by a titanium-walled vault.  Juno has a dual-mode propulsion system with adeployable micrometeoroid sheild for the main engine.  Attitudecontrol thrusters are used for re-orienting the spin axis and forsmaller trajectory/orbit corrections, and spin-up/down manuevers.  Thethermal design uses a cold-biased passive design with software-controlled heaters.  Attitude control is provided  using InertialMeasurement Units, Stellar Reference Units, Spinning Sun Sensors, andactive (thrusters) and passive (fluid-filled loop) nutation damping.Telecom is achieved with X-band uplink and downlink coupled with fiveantennas for completed coverage and including tones capability forcritical low-link margin telemetry.  Ka-band telecom is included forimproved Doppler measurement performance.  Essential systems areredundant and cross-strapped.  The z-axis of the spacecraft coordinatesystem is co-aligned with the HGA axis, hence, nominally points towardEarth.  The spacecraft x-axis is in the direction of the solar panel whichincludes the MAG boom at the end.  The y-axis completes a right-handorthogonal system.SPACECRAFT SUBSYSTEMS---------------------The spacecraft comprised several subsystems, which are described brieflybelow. For more detailed information, see JPLD-5564.Structures and Mechanisms Subsystem-------------------The spacecraft structure uses heritage composite panel and clipconstruction for decks, central cylinder, and gusset panels.Polar mounted off-center spherical tanks are consistent with a spinningspacecraft design with a high, stable inertia ratio.  The centralcylinder has high torsional stiffness.  Six gussets provide stiffnessfor the solar arrays.  Components are located such that they meet allmechanical requirements, including mass, field of view, magnetics, andalignments.  The radiation vault uses titanium panels that providestructure as well as shielding.  Assembly, Test, and Launch Operations(ATLO) access is easily available through 3 removable panels (top and 2sides).   The Telecom subassembly is contained on one panel.  Louverson the outside reject heat during Inner Cruise.  The vault also servesas a Faraday cage.  Spacecraft mechanisms include solar arrayarticulation, providing up to 4.5 deg. of wing tilt, and allowingapproximately 1.9 deg. of principal axis adjustment.  A main enginecover must open and close for each of 4 main engine burns as well asmain engine flushing burns, and also provides micrometeoroid protection.Solar array wings consist of 11 solar panels and 1 MAG boom.  They useheritage designs for (a) spring driven and viscously damped deployment,and (b) a multi-panel retention and release.Telecom Subsystem-------------------------The Gravity Science and Telecom Subsystem provides X-band command uplinkand engineering telemetry and science data downlink for the entire post-launch, cruise, and Jupiter orbital operations at Earth ranges up to 6.5AU.  The subsystem also provides for dual-band (X- and Ka-band) Dopplertracking for Gravity Science at Jupiter (concurrent X-band telemetryduring Gravity Sciences passes also contributes to data returnrequirements).  The subsystem is designed, built, and tested at JPLprior to delivery to Lockheed Martin.The non-science part of the subsystem is fully redundant.  The Ka-banduplink for Gravity Science is single-string as is the Ka-band poweramplifier.  The subsystem is designed to provide a minimum 2-sigmamargin on all links.  Juno will normally use NASA's Deep Space Network(DSN) 34-m subnet for communications.  The 70-m subnet will be usedfor critical event coverage post launch, reception of tones duringmain engine maneuvers (Deep Space Maneuvers (DSMs), Jupiter OrbitInsertion (JOI), and Period Reduction Maneuver (PRM)), enhanced data returnduring selected orbits at Jupiter, and for safe mode telecom.The telecom design is sized to provide a minimum science downlink rateof 18 kbps into a 34-m DSN station at max range (6.46 AU) duringorbital operations, and 12 kbps during Gravity Science perijove passes.Higher data rates will be used at shorter ranges or with a 70-m DSNstation.  The design also supports sending tone modulation during DSMs,JOI, and PRM burns when the spacecraft spin axis is nearly normal tothe Earth line.Telecom equipment includes two Small Deep Space Transponders (SDSTs),both with X/X and one with additional X/Ka capability.  The X/X/Kacapability serves as a partial backup for Gravity Science.  There aretwo 25-W X-band Traveling Wave Tube Amplifiers (TWTAs), 5 WaveguideTransfer Switches (WTSes), 2 X-band diplexers, filters, microwavecomponents, waveguide, and cabling.  These are all used to feed 5separate antennas.  The high-gain antenna (HGA) is a 2.5-m, shaped,axially symmetric, Gregorian, dual-reflector antenna fed by adual-band, coaxial, corrugated feed.  The HGA supports uplink anddownlink at both X and (carrier-only) Ka-band.  There is an X-bandmedium-gain antenna (MGA or F-MGA), foreward and aft low-gainantennas (LGAs, specifically F-LGA and A-LGA), and toroidalantenna (T-LGA) that provides coverage during the DSMs, JOI, and PRMburns.  The toroidal antenna is also used briefly during cruise whenthe Sun-Probe-Earth (SPE) angle is near 90 deg.All antennas except the toroidal antenna are aligned with thespacecraft Z axis, which will be aligned with the spin axis shortlyafter launch using the adjustable solar array wing actuators. The HGA,MGA, and foreward LGA are nearly co-boresighted (the MGA and LGAs areslightly offset from the spin vector).  The aft LGA is used whenthe spacecraft's trajectory goes inside of the Earth's orbit and theSPE angle is greater than 110 deg.The Ka-band Translator Subsystem (KaTS) receives a Ka-band uplinkthrough the HGA from the DSN (DSS-25) and coherently generates aKa-band downlink carrier signal and then amplifies the signal.  Thesignal is then guided to the Ka-band feed of the HGA for the GravityScience two-way Ka-band Doppler signal.  The KaTS is provided by theItalian Space Agency.Propulsion Subsystem---------------------------Juno uses a dual-mode Propulsion Subsystem, with a biprop main engine(ME) and monoprop Reaction Control System (RCS) thrusters.  The 12thrusters are mounted on 4 Rocket Engine Modules (REMs), allowtranslation and rotation about 3 axes, and provide some redundancy.There are 8 lateral thrusters, canted away from X by 5 deg. along Yand by 12.5 deg. along Z, and 4 axial thrusters, canted away from Zby 10 deg. along Y.  6 equal-sized spherical propellant tanks containfuel (4 tanks) and oxidizer (2).  Biprop mode (N2O4/hydrazine) isused for major maneuvers and flushing burns, and monoprop mode(blowdown hydrazine) is used for spin-up and -down, precession,active nutation damping, and most Trajectory CorrectionManeuvers (TCMs) and Orbital Trim Maneuvers (OTMs).  The Leros-1b mainengine is well-characterized, and is fixed on the Z axis, pointingaft.  Isolation valve ladders included in the pressurization systemeliminate propellant mixing concerns.  RCS thrusters are located tominimize plume interactions.  The propellant tanks are sizedconsistent with the planned delta-V budget, for the maximumspacecraft mass that can be lifted by an Atlas V 551 to the requiredcharacteristic energy (C3).Electrical Power Subsystem (EPS)--------------------------------Juno's redundant, single fault tolerant Electrical Power Subsystemmanages the spacecraft power bus and distribution of power to payloads,propulsion, heaters, mechanism motor actuators, NASA Standard Initiators(NSIs), and avionics.  The Power Distribution and Drive Unit (PDDU)monitors and manages the spacecraft power bus, manages the availablesolar array power to meet the spacecraft load and battery state ofcharge (SOC), and provides controlled power distribution.  The PyroInitiator Unit (PIU) includes a redundant, dual fault tolerantPyrotechnic Initiator Module (PIM).  Power generation is providedby 3 solar arrays using current generation UTJ solar cells.  Two 55A-hr Li ion batteries provide power when Juno is off-Sun or ineclipse, and are tolerant of the Jupiter radiation environment.  Thepower modes during Science Orbits are sized for either an MWR (favorableattitude for the Microwave Radiometer instrument) or a GRAV orbit, andprovide sufficient margin given the expected loads during perijove sciencepasses as well as DSN telecom passes.  Sufficient power and energy marginshave also been demonstrated for the Launch, DSMs, JOI, PRM, and deorbit burnmission events, as well as safe mode near End of Mission (EOM).Command and Data Handling Subsystem (C&DH)--------------------------The C&DH is based on two redundant, single fault tolerant boxesdeveloped for Mars Reconnaissance Orbiter (MRO).  Each C&DH box includes acPCI bus interconnected to 3U cards (except the DTCI card which uses 6Uformat) and a RAD750 flight processor with 256 MBytes of NVM flash memoryand 128 MBytes of SFC DRAM local memory.  It provides 100 Mbps totalinstrument throughput, more than enough for payload requirements.32 Gbits (base 2, EOL) of science data storage (plus 8 Gbits forEDAC) are available on the DTCI card, which has been demonstratedto be sufficient for minimum and maximum science orbit downlink datarequirements, and representative stress cases that account for dataretransmission and prioritization.Guidance, Naviation, and Control Subsystem (GN&C)-------------------------------------------The Juno GN&C Subsystem uses spin-stabilized control.  The launchspin rate of 1.4 RPM is initiated by the launch vehicle upper stage(and adjusted by the spacecraft after solar array deployment).  Theplanned spin rate varies during the mission: 1 RPM for cruise, 2 RPMfor science operations, and 5 RPM for main engine maneuvers.  MWR andGRAV orbits at Jupiter use 2 different spacecraft attitudes: spinaxis parallel to orbit normal for MWR orbits, and HGA Earth-pointedfor GRAV orbits.  Precession and spin control use balanced mode forminimum delta-V, and are capable of unbalanced mode for lower fueluse (although not planned to be used).  Active nutation dampingrequires the Inertial Measurement Units (IMUs).  Delta-V maneuversusing the RCS thrusters can be either turn-burn-turn (TBT), whichrequires precession to turn to the desired attitude, or vector-mode(Vect), in which thrust is provided in both axial and lateraldirections.  Main engine maneuvers require precession to point theengine in the desired direction.  One of two Stellar ReferenceUnits (SRUs) and one of two Spinning Sun Sensors (SSSes) arecontinuously powered (the SRU is turned off for ME burns, and bothSSSes are powered on during safe mode).  One of two IMUs is poweredfor delta-V maneuvers, large precessions (larger than ~2.5 deg.),active nutation damping, and spin control.Temperature Control Subsystem (TCS)-----------------------------Juno's Thermal Control Subsystem uses a passive cold biased designwith heaters and louvers.  The core TCS consists of an insulated,louvered electronics vault atop an insulated, heated propulsion module.This design accommodates all mission thermal environments fromperihelion to orbital operations.  During cruise, while the spacecraftis close to the Sun, the HGA is used as a heat shield to protect thevault avionics.  Outside ~1.4 AU, the spacecraft pointing isunrestricted, while inside ~1.4 AU Sun-pointing and off-Sun-pointingare required.  Most instrument electronics are contained within theradiation vault and are thermally managed as part of the vault TCS.Science sensors are externally mounted to the deck and are individuallyblanketed and heated to maintain individual temperature limits.JUNO SCIENCE INSTRUMENTS---------------------------Juno's instrument complement includes Gravity Science using the X and Ka bandsto determine the structure of Jupiter's interior; magnetometer investigation(MAG)  to study the magnetic dynamo and interior of Jupiter as well as toexplore the polar magnetosphere; and a microwave radiometer (MWR) experimentcovering 6 wavelengths between 1.3 and 50 cm to perform deep atmosphericsounding and composition measurements.  The instrument complement alsoincludes a suite of fields and particle instruments to study the polarmagnetosphere and Jupiter's aurora.  This suite includes an energetic particledetector (JEDI), a Jovian auroral (plasma) distributions experiment (JADE), aradio and plasma wave instrument (Waves),  an ultraviolet spectrometer (UVS),and an Jupiter infrared auroral mapping instrument (JIRAM).  The JunoCam is acamera included for education and public outreach.  While this is not ascience instrument, we plan to capture the data and archive them in the PDSalong with the other mission data.  The MAG investigation consists ofredundant flux gate magnetometers (FGM) and co-located advanced stellarcompasses (ASC).  The ASCs are provided by the Danish Technical Universityunder an effort led by John Jorgenson.Scott Bolton is the Juno Principal Investigator.  The Science Team membersresponsible for the delivery and operation of the instruments are listedbelow:Instrument                                      Acronym   Lead Co-I----------------------------------------------  --------  ---------Gravity Science                                 GRAV      FolknerMagnetometer                                    MAG       ConnerneyMicrowave Radiometer                            MWR       JanssenJupiter Energetic Particle Detector Instrument  JEDI      MaukJovian Auroral Distributions Experiment         JADE      McComasRadio and plasma wave instrument                WAVES     KurthUltraviolet Imaging Spectrograph                UVS       GladstoneJovian Infrared Auroral Mapper                  JIRAM     Coradini*Juno color, visible-light camera                JUNOCAM   HansenStellar Reference Unit                          SRU       BeckerAdvanced Stellar Compass                        ASC       Joergensen*deceasedGravity Science (GRAV):  The Gravity Science investigation was designed tomap Jupiter's graviational field.   -  Determine normalized gravity coefficients J4, J6, and J8 - J14Magnetometer (MAG):  The Magnetometer investigation was designed to mapJupiter's magnetic field.   -  Derive a spherical harmonic model of Jupiter's main magnetic      field through degree and order 14Microwave Radiometer (MWR):  The Microwave Radiometer was designed tocharacterize Jupiter's atmosphere.   -  Determine the global O/H ration (water abundance) in Jupiter's      atmosphere   -  Measure latitudinal variations in Jupiter's deep atmosphere      (composition, temperature, cloud opacity, and dynamics)   -  Measure the microwave brightness temperatures of Jupiter over all      latitudes at wavelengths that fully sample the atmospheric thermal      emission at all altitude levels from the ammonia cloud-forming      region to below the water cloud-forming regionJupiter Energetic Particle Detector Instrument (JEDI):  The JupiterEnergetic Particle Detector Instrument was designed to characterizeJupiter's polar magnetosphere.   -  Measure the pitch angle and energy distribution of electrons      across auroral featuresJovian Auroral Distributions Experiment (JADE):  The Jovian AuroralDistributions Experiment was designed to characterize Jupiter'spolar magnetosphere.   -  Measure three dimensional time variable, pitch angle, energy and      composition distribution of ions   -  Measure ion composition to differentiate between H+, H2+, H3+,      O+, and S+.Radio and Plasma Wave Instrument (Waves):  The Waves instrument wasdesigned to characterize Jupitter's polar magnetosphere.   -  Measure radio and plasma wave emissions associated with      auroral phenomena in the polar magnetosphereUltraviolet Imaging Spectrograph (UVS):  The Ultraviolet ImagingSpectrograph was designed to characterize Jupiter's polarmagnetosphere.   -  Characterize the UV auroral emissionsJovian Infrared Auroral Mapper (JIRAM):  The Jovian Infrared AuroralMapper was designed to characterize Jupiter's atmosphere.Juno color, visible-light camera (JUNOCAM):  The Juno color, visible-light camera was designed to engage the public and educate students.Advanced Stellar Compasses (ASC):  These are four low-light camerasthat provide quaternions for the two fluxgate magnetometer assemblieson the magnetometer boom. They also may provide science images ofnon-stellar objects and for dust studies.Stellar Reference Unit (SRU): The Stellar Reference Unit (SRU) isoperated as a broadband visible (450-1100 nm) science imager for thepurpose of studying low-light features and phenomena of the Joviansystem, such as Jupiter's faint dust ring and lightning. It is alsoused as an in situ particle detector for studying the high energyradiation environment at Jupiter.  Instrument Host Overview - DSN  ================================Radio Science investigations utilized instrumentation withelements both on the spacecraft and at the NASA Deep Space Network(DSN).  Much of this was shared equipment, being used for routinetelecommunications as well as for Radio Science.The Deep Space Network was a telecommunications facility managed bythe Jet Propulsion Laboratory of the California Institute ofTechnology for the U.S.  National Aeronautics and SpaceAdministration.The primary function of the DSN was to provide two-way communicationsbetween the Earth and spacecraft exploring the solar system.  To carryout this function the DSN was equipped with high-power transmitters,low-noise amplifiers and receivers, and appropriate monitoring andcontrol systems.The DSN consisted of three complexes situated at approximately equallyspaced longitudinal intervals around the globe at Goldstone (nearBarstow, California), Robledo (near Madrid, Spain), and Tidbinbilla(near Canberra, Australia).  Two of the complexes were located in thenorthern hemisphere while the third was in the southern hemisphere.The network comprised four subnets, each of which included one antennaat each complex.  The four subnets were defined according to theproperties of their respective antennas: 70-m diameter, standard 34-mdiameter, high-efficiency 34-m diameter, and 26-m diameter.These DSN complexes, in conjunction with telecommunications subsystemsonboard planetary spacecraft, constituted the major elements ofinstrumentation for radio science investigations.    For more information see [ASMAR&RENZETTI1993]