Goddard Space Flight Center Jet Propulsion Laboratory National Aeronautics and Space Administration...

Goddard Space Flight CenterJet Propulsion Laboratory

National Aeronautics and Space Administration

05/31/20151

Launch Configuration

Juno Spacecraften route to

Jupiter

(Arrives July 4th 2016)

National Aeronautics andSpace Administration


PI: Scott Bolton SWRI

Juno MissionJack Connerney

May 31, 2015



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Jupiter holds the secrets of solar system formation deep within the interior



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Galileo Probe – Where’s the Water?

3

Original Mission Plan Orbits

Revised Mission Plan Orbits

View from Earth

Looking Down the North Pole

2 x 53 day orbits

14 day orbits

Sun



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Orbits 1, 16 and 31 pictured

Juno orbits over Jupiter’s poles and passes very close to the planet.

Juno ducks under the hazardous radiation belts. Over time, radiation exposure increases.



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Juno’s orbits are phased to envelope Jupiter in a dense mesh of potential field measurements - magnetic and gravity fields – to probe the deep interior.

Juno will Earth-point on most periapsis passes for gravity measurements and re-orient slightly on others to optimize viewing for other instruments.



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Magnetometer(2 MAG sensors, 4 star cameras)

JADE(4 sensors )

JEDI(6 sensors )JIRAM

Waves(2 detectors)

JunoCam

UVS

Gravity Science(2 sensors)

MWR(6 sensors )

SPACECRAFT DIMENSIONSDiameter: 66 feet (20 meters)Height: 15 feet (4.5 meters)

Juno Spacecraft & Payload

Scott Bolton



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Juno Mission Context

Juno today (L+1395)

(400 days ‘till JOI)

Aug 11, 2011 EFB

EARTH

MARS

JUPITER

CERES

VENUS

main asteroid belt

Oct 9, 2

013



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Spacecraft tracks

Along-track scanning

Probing Deep and Globally

• Microwave radiometry probes deep into the meteorological layer

• Magnetic fields probe into dynamo region of metallic hydrogen layer

• Gravity fields probe into central core region

Juno probes deep into Jupiter in three ways:



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Microwave Radiometer (MWR)

Spacecraft tracks


120° Field of View

A1: patch array

A3 - A5: slot arrays

A2: patch array

A6: horn


nadir view

off-nadirview emission

angle

The microwave antennas are distributed around the spacecraft and view perpendicular to the spacecraft spin axis



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Microwave Sounding

Weighting functions: Measurement wavelengths sample atmosphere from cloud tops to >> 100 bar.

Footprints: atmosphere densely sampled along sub-spacecraft track. 12º and 20° footprints are displaced for clarity. Only 1 of every 1200 footprints is shown.

12° footprints(1.37 – 11.55 cm)

20° footprints(24,50 cm)



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Mapping Jupiter’s gravity

•High eccentricity orbits•Period: 14 days•6h tracking at Ka band•Periapsis altitude ~ 5000 km•Range rate accuracy 3 x10-6

m/s @ 1000 s integration

Ka-band radio system (32-34 GHz)



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Juno Gravity Investigation

• 25 (24) gravity passes anticipated at this time

• Gravity science also available during MWR passes

• Orbit close to face-on (20º) initially (periapsis near dusk)



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Juno Gravity Investigation



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Jupiter’s “Surface” Gravity

Shallow winds (H = 300 km) Deep winds (H = 3000 km)

Gravity field accuracy is ~ 0.2 mGal at best, increasing up to 30 mGal in the polar regions

(8 mGal)(0.15 mGal)



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Juno MAG Instrument Suite

Two Identical MAG Optical Bench (MOB) Assemblies populate the MAG Boom,

one InBoard (IB), one OutBoard (OB) @ 10, 12 m.

CSiC MOB

FGM Sensor

FGM Sensor

ASC CHUs

Optical Cube

ASC = Advanced Stellar CompassCHU = Camera Head UnitFGM = Fluxgate Magnetometer

CHU Inner Light Baffles



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Juno Magnetometer Suite

Magnetic Observatory Characteristics

Sensors Type: Dual Tri-axial Ring Core Fluxgates, each withtwo co-located Non-Magnetic Star Cameras

Dynamic Ranges & (resolution)

Range 6:Range 5:Range 4:Range 2:Range 1:Range 0:

16.384 G (+/- 25. nT)4.0960 G (+/- 6.25 nT)1.0240 G (+/- 1.56 nT)0.2560 G (+/- 0.39 nT)0.0640 G (+/- 0.19 nT)0.0160 G (+/- 0.05 nT)

FGM Vector Accuracy: ~0.01% of full scale

FGM Intrinsic Noise Level: << 1 nT

FGM Zero Level Stability: < 1 nT

Spacecraft Magnetic Cleanliness: < 2 nT Static and < 0.5 nT Dynamic

Intrinsic FGM Sample Rate: 64 Vector Samples/Second

Advanced Stellar Compass: Four Camera Head Units (CHUs), CCD Imager

Attitude Determination Accuracy: ~10 Arcsec (spin rate dependent)

Attitude Solution Rate: 4 Quaternions per second



• Characterize Jovian internal field to spherical harmonics n > 14, and

provide unprecedented resolution of the dynamo process.

Magnetic Spectra

• Explores polar magnetosphere.• ∆B measures Birkeland currents as Juno passes through auroral oval.• Provides vector B to payload.

MAG Science Objectives



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Jovian Auroral Dynamics Experiment

3 JADE-Electron Sensors

JADE-Ion Sensor

JADE Central Electronics Unit



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JADE Measurements Summary

JADE-E(3 Sensors)

JADE-I

Energy Range 100 eV – 100 keV 10 eV/q – 50 keV/q

E/E 10-14% (depends on E) 18-28% (depends on E)

FOV (Inst) 360°x 3-6° 270°x 8.5°

FOV Tracking Uses 1s MAG data -

Pixels/Res 3 Sensors x 16 / 7.5° 12 / 22.5°

Mass Range - 1 - 64 amu

M/DM - 2.5 – 11 (depends on M & E)

G factor/pixel ~2-5 x10-5 cm2 sr eV/eV ~4 x10-5 cm2 sr eV/eV

Time Res Full PAD each 1s 4p each 30s spin



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JADE Science Objectives

• Explore polar magnetosphere, auroral region electrons & ions

• Characterize precipitating particle distributions that drive auroral emissions

• Identify particle acceleration processes

• Examine composition and mass loading from satellites

• Observe plasma disk, middle magnetosphere; address structure & evolution

• Collaborative studies with other Juno measurements



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Juno Energetic Particle Detectors

JEDI



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Three Juno Energetic Particle Detector Instruments (JEDI) measure energetic electrons and ions that help cause Jupiter’s aurora

Juno Energetic Particle Detectors

Parameter Capability Comment

Electron Energies 25 – 1000 keV Abuts JADE

Ion Energies H+: 15-10000 keVHe: 25-10000

O/S+: 40-100000 keV

Abuts JADE

Time Sampling 25% Earth AuroraSpectra Driver

Angle Resolution 18° using rotation <= 30 km AuroralSampling /

Pitch Angle (PA) Coverage

0-360 degrees for whole Orbit Resolve loss coneR < 3 RJ /

Ion composition H above 10 keVHe above 50 keVO Above 45 keV

Separate S from O for E > 200 keV



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Juno flies through the auroral acceleration region; JEDI characterizes: particle precipitation, heating and ionization in the upper atmosphere and signatures of the structure of Jupiter’s polar space environment.

Is downward acceleration (to 500 keV at Jupiter) coherent (like Earth) or diffuse?

What is the role of acceleration in global auroral current systems?

Enough precipitating heavy ions (many MEV) to explain auroral X-ray emissions?

Juno’s Unique Location



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Juno Waves Overview

Preamps & Electronics

Search Coil



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Juno Waves Instrument

Instrument Characteristics

Spectral Coverage: 50 Hz – 20 kHz Magnetic

50 Hz – 40 MHz Electric

Spectral Resolution: ~20 Channels/decade

Periapsis Mode Cadence: 1 spectrum/second

LF and MF Burst Modes: Waveform Captures in all bands to 150 kHz triggered onboard

HF Burst Modes: Ability to select a 1-MHz band including fce


National Aeronautics and Space Administration Waves Science Objectives

• Explore radio and plasma waves in the polar magnetosphere

• Examine the role of plasma waves in the auroral acceleration region

• Identify and observe in-situ source regions of Jovian radio emissions

• Additional Science Objectives:> Observe the structure and dynamics of the plasmasheet

> Monitor radio emissions as a proxy for magnetospheric dynamics

> Measure dust impacts between the ring system and the atmosphere


National Aeronautics and Space Administration Juno UVS Overview

-30º

0º

+30ºEntrance Baffle

Scan Mirror Assembly

Detector Electronics

XDL Detector Assembly

Grating

Telescope/Spectrograph

Off-axis Primary Mirror

Aperture Door

Slit Assembly

Scan Mirror Rotation Axis

Projection of UVS slit on sky



Feature Characteristic or Performance Driving Requirement

Spectral Range: 70-205 nm 78-172 nm (H2 & H emissions)

SpectralResolution

~0.40.6 nm (point source); ~1.02.6 nm (extended)

<3 nm filled slit (color ratio)

SpatialResolution

0.1° (125 km from 1 RJ above the aurora) <500 km (HST-like spectral imaging)

Effective Area: 0.002 cm2 @ 105 nm, 0.02 cm2 @ 170 nm >100 kR (moderately bright auroras)

IFOV: 0.2° x 2.5° + 0.025° x 2° + 0.2° x 2.5° → “dog-bone” shape

Field of Regard: 360° x 60° (2 RPM & ±30° from spin plane → half the sky is accessible)

Detector Type: Curved 2-D MCP (solar blind), Csl photocathode, cross delay-line (XDL) readout, 24 bits/event; 2048 spectral (perpendicular to slit) x 256 spatial (parallel to slit) x 32 (PHD)

Juno UVS Performance



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UV Auroral Emissions:– H2 Lyman Bands (80-170 nm) ~40%– H2 Werner Bands (80-130 nm) ~40%– H2 Rydberg Bands (80-90 nm) ~5%– H Lyman series (121.6 nm, etc.) ~15%

• Imaging and spectroscopy of UV auroral emissions: Imaging auroral morphology,

mapping emission to provide context for in-situ particles and fields measurements

Spectroscopy to determine the mean energy of precipitating electrons

Magnetic field models map from Juno s/c to polar field line footprint

HST FUV Image

Clarke et al. 2002

• Additional Science Objectives: Observe the S/C footprint region to compare UVS data with particle & waves data Look for structure & variability in low-latitude airglow emissions Determine auroral-region atmospheric composition using reflected sunlight

Juno UVS - Jovian Aurora



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Juno – JIRAM

Jovian InfraRed Auroral Mapper

Scanning Concept Optical Head Focal Planes Assembly



33


• JIRAM is both an imager and a spectrometer.

• Heritage from: Cassini, Venus Express, Dawn and Rosetta.

• The spectrometer operates in the spectral range 2-5 µm (resolution of 9 nm).

• The imager has two

contiguous channels at

3.3-3.6 µm for auroras

and at 4.5-5.0 µm for

Jovian thermal emission.

• H3+ has strong emissions

throughout JIRAM’s

spectral range.



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JIRAM maps Jovian aurorae at infrared wavelengths emitted by H3+.

This ion is formed at the base of the exosphere through the reaction H2

+ + H2 H3+ + H.

JIRAM will visualize Jovian infrared auroral emissions in conjunction with ultraviolet auroral emissions observed by Juno’s UVS.NADIR and limb observations with JIRAM’s spectrometer measures temperature and concentrations of emitting ions.


December 16, 2000 (UT) Observations

IRTF/NSFCAMH3+ Image

12:24 UT

HST/STISSUV Image

12:26 UT



05/31/2015

JunoCam • JunoCam was conceived as a small EPO

camera but it does enjoy unique polar views • Camera designed for optimum performance

when Juno has best polar views

Science Objectives• Polar meteorological phenomena• Observe small-scale structure of storms

(resolution 10x better than previous missions)• Provide context for data from deeper in the

atmosphere (JIRAM and MWR)



05/31/2015

JunoCam

• JunoCam is a fixed field of view push-frame visible camera that images in four color bands: Blue, green, red, and Methane band.

• Uses time-delay integration (TDI) on spinning spacecraft to increase signal-to-noise ratio (snr).

• JunoCam is a heritage design of the Mars Science Laboratory (MSL) rover Mars Descent Imager (MARDI) with limited modifications, built by Malin Space Science Systems

• 1600 pixel, 58º wide FOV



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JunoCam Outreach

• Engage the public– Provide insight into the scientific

planning process, factors that influence scientific decisions

• Rely on amateur astronomers to supply images of Jupiter for planning purposes

• Include college students in the outreach effort and blogs

• Include public in target selection • Image processing community will

produce color images, movies, etc. – demonstrated at earth flyby



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Juno EFB Overview

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Earth and Moon

As seen by the Juno spacecraften route to Jupiter

October 9th 2013

J L Joergensen et al. Technical University of Denmark

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