1 MAVEN PFP ICDR May 23-25, 2011 Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission Particles...

1MAVEN PFP ICDR May 23-25, 2011

Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission

Particles and Fields ScienceCritical Design Review

May 23 -25, 2011

Dave Mitchell SWEA Lead


MAVEN Science Questions

MAVEN will determine the role that loss of volatiles to space has played through time, providing definitive answers about Mars climate history:

• What is the current state of the upper atmosphere and what processes control it?

• What is the escape rate at the present epoch and how does it relate to the controlling processes?

• What has the total loss to space been through time?


MAVEN Mission Architecture

• In situ and semi-global remote sensing measurements are made from the MAVEN elliptical orbit.

• Measurements are obtained down to the well-mixed lower atmosphere through five “deep dip” campaigns.

• Coverage of all local solar times and most latitudes, along with broad geographical coverage, results from precession of the MAVEN high-inclination orbit.


IUVS

NGIMS

Neutral Processes

MAVEN Measures Drivers, Reservoirs, and Escape Rates

SEP

SWEA

MAG

Solar Inputs

EUV

SWIA

LPW

MAG

SWEA

Plasma Processes

IUVS

SWIALPW

STATIC


The MAVEN Payload Makes the Essential Measurements

NGIMS

IUVS

LPW

integrated analysis

integrated analysis

STATIC

MAG, SWEA, SWIA, LPW

SEP

LPW - EUV


STATIC Measurement Requirements

• STATIC measures low- and medium-energy ion composition, energy, and direction:– Densities, velocities, and temperatures of suprathermal H+, O+, O2+,

and CO2+ above the exobase with the ability to spatially resolve magnetic cusps

• Derived Level 3 measurement requirements:

ID Title Parent ID Description

PF55 STATIC Flux Range 1 MRD61 STATIC shall measure energy fluxes from 1E7 to 1E10 eV/cm2-sec-ster-eV with 20 second resolution and 25% accuracy and precision

PF56 STATIC Flux Range 2 MRD62 STATIC shall measure energy fluxes from 1E4 to 1E8 eV/cm2-sec-ster-eV with 30 minute resolution and 25% accuracy and precision

PF57 STATIC Mass Range MRD63 STATIC shall measure ions from at least 1-44amu

PF58 STATIC Mass Resolution MRD64 STATIC shall have mass resolution m/dm of at least 2 (m/dm)

PF59 STATIC Energy Range MRD65 STATIC shall measure ions from 1 eV to 10 keV

PF60 STATIC Energy Resolution MRD65 STATIC shall have energy resolution dE/E of at least 30%

PF61 STATIC Angular Resolution MRD65 STATIC shall have angular resolution of at least 30 degrees

PF62 STATIC FOV MRD66 STATIC shall have a FOV at least 60 degrees by 180 degrees

PF63 STATIC Time Resolution 1 MRD61 STATIC shall have time resolution of 20 seconds or better for Flux range 1

PF64 STATIC Time Resolution 2 MRD62 STATIC shall have time resolution of 30 minutes or better for Flux range 2


SWEA Measurement Requirements

• SWEA measures properties of solar wind electrons that can drive escape:– Energy distributions of solar wind, magnetosheath, and ionospheric

electrons to determine the electron impact ionization rate, with an energy resolution sufficient to distinguish ionospheric photoelectrons from solar wind electrons

– Electron angular distributions to determine magnetic topology, with the ability to spatially resolve magnetic cusps.

• Derived Level 3 measurement requirements:ID Title Parent ID Description

PF65 SWEA Flux Range MRD68 SWEA shall measure energy fluxes from 1E4 to 1E8 eV/cm2-sec-ster-eV

PF66 SWEA Sensitivity MRD69 SWEA shall have a geometric factor > 0.005 cm2-ster

PF67 SWEA Energy Range MRD70 SWEA shall measure electrons from 10 - 1000eV

PF68 SWEA Energy Resolution MRD70 SWEA shall have energy resolution dE/E of at least 25%

PF69 SWEA Time Resolution MRD71 SWEA shall have time resolution of 20 seconds or better

PF70 SWEA Angular Resolution MRD72 SWEA shall have angular resolution of at least 45 degrees

PF71 SWEA FOV MRD73 SWEA shall have a FOV which covers at least 50% of the sky


SWIA Measurement Requirements

• SWIA Measures properties of solar wind ions that can drive escape:– Density and velocity distributions of solar wind and magnetosheath ions

to determine the charge exchange rate and the bulk plasma flow from solar wind speeds down to stagnating magnetosheath speeds



PF72 SWIA Flux Range MRD75 SWIA shall measure energy fluxes from 1E7 to 1E10 eV/cm2-sec-ster-eV

PF73 SWIA Flow Velocity MRD76 SWIA shall measure ion flow velocities from 50-1000 km/s

PF74 SWIA Energy Resolution MRD77 SWIA shall have energy resolution dE/E at least 15%

PF75 SWIA Angular Resolution MRD78 SWIA shall have angular resolution of at least 30 degrees (10 degrees in Sun direction)

PF76 SWIA Time Resolution MRD79 SWIA shall have time resolution of 1 minute or better

PF77 SWIA FOV MRD80 SWIA shall have a FOV of 180 x 40 degrees or better


Cross Calibration of STATIC/SWEA/SWIA

• The angular and energy responses and the geometric factor (minus detection efficiency) for all three instruments are determined on the ground to within ~10% by calibrations and electrostatic optics simulations.

• Detection efficiency depends on MCP efficiency, which varies during the mission need a procedure to measure and track this efficiency for all three instruments.


PF105 STATIC Accuracy MRD35, MRD52

STATIC shall have an in-flight calibration procedure to determine its absolute sensitivity to within 25%.

PF106 SWIA Accuracy MRD35, MRD52

SWIA shall have an in-flight calibration procedure to determine its absolute sensitivity to within 25%.

PF107 SWEA Accuracy MRD35, MRD52

SWEA shall have an in-flight calibration procedure to determine its absolute sensitivity to within 25%.

New Level 3 Requirements

Response to RFAs 9 and 10



• Detection efficiency for STATIC:

– Determine START and STOP efficiencies by measuring event ratios: (START with STOP)Valid and (STOP with START)Valid

STARTValid STOPValid

– This can be done anywhere that the ion composition is dominated by a single

species (e.g., H+ in the outer sheath, O2+ in the ionosphere).

– For cross calibration of SWIA and SWEA, efficiencies for H+ are needed.

STATIC can meet requirement without cross calibration.

– Consistency check: Measure total plasma density near periapsis and compare with calibrated LPW measurements.




• Absolute sensitivity of SWIA determined by cross calibration with STATIC in the outer sheath

– Instruments have the same analyzer optics and overlapping energy and angle ranges, so measurements of ion flux are sufficient for comparison.

• Absolute sensitivity of SWEA determined by cross calibration with SWIA and STATIC in the outer sheath and with SWIA in the solar wind.

– Modeling of total density needed in the sheath for all three.

– Modeling of total density needed for SWEA in the solar wind.



SEP Measurement Requirements

• SEP Measures solar energetic particle input into upper atmosphere:– Solar energetic particles that can interact with the upper atmosphere,

with a time resolution sufficient to capture SEP events.



PF78 SEP Flux Range MRD87 SEP shall measure energy fluxes from 10 to 1E6 eV/cm2-sec-ster-eV

PF79 SEP Energy Range MRD88 SEP shall measure ions from 50keV to 5 MeV

PF80 SEP Energy Resolution MRD89 SEP shall have energy resolution dE/E of at least 50%

PF81 SEP Time Resolution MRD90 SEP shall have time resolution of 1 hour or better


MAG Measurement Requirements

• MAG measures solar-wind interactions and “mini-magnetospheres”– Vector magnetic field in the unperturbed solar wind, magnetosheath, and

crustal magnetospheres, with the ability to spatially resolve crustal magnetic cusps.



PF82 MAG Dynamic Range MRD82 MAG shall measure magnetic fields from 3 to 3000nT

PF83 MAG Accuracy MRD83 MAG shall have an accuracy of better than 1% over its dynamic range

PF84 MAG Resolution MRD84 MAG shall have resolution of better than 1% over its dynamic range

PF85 MAG Time Resolution MRD85 MAG shall have time resolution of 20 seconds or better (5 seconds below 400km)


LPW Measurement Requirements

• LPW shall measure electron temperature and number density measured in situ:– Thermal electron density and temperature from the ionospheric main

peak to the nominal ionopause with a vertical resolution of one O2+ scale height.

• LPW shall measure electric field wave power– at frequencies important for ion heating.

• Derived Level 3 measurement requirements:ID Title Parent ID Description

PF86 LPW Density Range MRD53 LPW shall measure electron densities from 1E2 to 1E6 cm-3

PF87 LPW Density Accuracy MRD53 LPW shall have density (n) precision of 20% and a relative (dn/n) precision of at least 5% below the ionopause

PF88 LPW Temperature Range MRD54 LPW shall measure electron temperatures from 500 to 5000 K below the ionopause

PF89 LPW Temperature Accuracy MRD54 LPW shall have temperature precision dT/T of at least 20% below the ionopause

PF90 LPW Frequency Range MRD55 LPW shall measure waves from 0.05 to 10Hz

PF91 LPW Wave Power Sensitivity MRD55 LPW shall have wave power sensitivity of at least 1E-8 (V/m)2/Hz

PF92 LPW Spatial Resolution MRD56 LPW shall have time resolution of 15 seconds or better


LPW/EUV Measurement Requirements

• EUV shall measure solar EUV input into upper atmosphere:– Solar EUV irradiance at wavelengths important for ionization,

dissociation, and heating of the upper atmosphere with a time resolution sufficient to capture solar flares.



PF93 LPW/EUV Saturation Current MRD57 LPW/EUV shall have saturation current resolution dl/l of at least 15%

PF94 LPW/EUV Photodiode Current MRD58 LPW/EUV shall have photodiode current resolution dl/l of at least 15%

PF95 LPW/EUV Time Resolution MRD59 LPW/EUV shall have time resolution of 10 minutes or better


PF Instrument Backups

Instrument Primary Backups Secondary Backups

NGIMS IUVS STATIC, LPW

IUVS NGIMS EUV

LPW NGIMS (Ne) STATIC (Te), MAG (waves)

EUV LPW SWEA, Earth-based

STATIC SWIA

SWEA SWIA STATIC, LPW

SWIA STATIC, SWEA

SEP SWEA, SWIA, STATIC

MAG MAG SWEA

PF


PF Measurement Resiliency

Objective 1 Objective 2 Objective 3

Instrument Current State Processes Escape Rates Processes Evolution

NGIMS N - N N N

IUVS N N N P N

STATIC - N S S N

SEP - N - N N

SWEA N N N N N

SWIA - N N N N

LPW N N N N N

EUV - N N N N

MAG N N N N N

If we lose any one instrument, do we lose any high-level objectives?

(Y = Yes, S = Substantial, P = Partial, N = Not significant, - = Minimal contribution)

PF

1 MAVEN PFP ICDR May 23-25, 2011 Mars Atmosphere and Volatile EvolutioN (MAVEN) Mission Particles...

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