MEIDEX

D - 1

MEIDEX – Operational Philosophy

IAFSpace BranchMajor Meir Moalem

MEIDEX

D - 2

Problem

• Dust storms are random events

• …So are sprites

• Abundance is different throughout the year

• ROIs are limited

• Airplane location - another constraint

MEIDEX

D - 3

Solution

• Define “rigid” ROIs

• Have a valid forecast

• Maximize observation opportunities– Record every pass of ROI with sufficient lighting

– Additional degree of freedom (truss)

• Allow for flexibility in operational activation

• Collect a large sample of scientific data

• Define secondary, tertiary missions

MEIDEX

D - 4

General

• Aerosols backscattered light measurements

• Xybion multi-spectral camera, 6 W/L NIR to NUV, 14*10 FOV

• SEKAI CCD viewfinder, 60º FOV

• ADVCR digital recorders, 360 min total time

• Canister with 16" quartz window and HMDA

• Operated by PGSC WIN98 software

• Backup recording at the AFD (DSR-20)

MEIDEX

D - 5

The MEIDEX Payload

Gimbal Motor and Worm Drive

Worm Gear

SEKAI Camera

Lower End Plate

Upper End Platew/ Quartz Window

Upper support plates

Optical Bench/Support

Xybion Camera

Lens and Baffle

Avionics Mount Platew/ electronics

Bearing and Brake (both sides)

MEIDEX

D - 6

Operational Event Cycle

• Dust forecast

• Observation planning:– Where (if exists) is the dust plume?

– Where is the Shuttle?

– Where is the airplane?

– Secondary mission?

• Execute package

• Observation

• Astronaut (operations, backup, feedback)

• Quick analysis and re-plan

Fusion

MEIDEX

D - 7

Who’s Who and Where

• TAU forecast center

• POCC

• Air Plane Base (Crete)

• Aeronet stations

• Sprites VLF stations

TAU forecast center

Atlantic ROI

POCCExp. Command

&Control Med. ROI

SPRITES

Global coordination in Real TimeSTK scenario

MEIDEX

D - 9

Secondary Missions

• Sprites – ionospheric TLEs

• Sea surface (Albedo)

• Slant visibility studies

MEIDEX

D - 10

Nominal (aerosols) Operations

• Bay-to-earth attitude, -ZLV directed to pass target (as forecasted), nadir view or a small bias

• Activate payload, use SEKAI for orientation

• “fine tune” truss pointing to dust plum (if possible)

• Record science data on MEIDEX canister and AFD (DSR-20)

• Monitor storm developments

• Supply ground planners with any useful information

MEIDEX

D - 11

Sprite Operations

• General convective forecasts, large possible areas (stk pic)

• Earth limb view attitude– Tail (or nose) to earth

– Bay away from RAM

• FOV pointing above horizon

• Record lightning activity

• “fine tune” with truss

MEIDEX

D - 12

Execute Package

• What’s in it?– Time of operations

– Location of targets (dust plumes, sprites)

– Location of airplane

– Forecast maps

– Payload related data \ instructions

– Any other remarks

• When will it be provided?– 24H in advance

– 1-2 times per mission day / shift

MEIDEX

D - 13

Example: Day # 007

• Data from mission timeline:– 4 observational opportunities

– 2 * dust, 2* sprites

• STK scenario:– Where is the shuttle?

– Where is the airplane?

– Define exact timeline for operation

• Ex. Pkg.:

• Observation from space, monitor from ground

• Feedback? Changes between orbits

MEIDEX

D - 14

Back-up Recording

• Recording within the payload: 360 min.

• Backup #1: DSR-20– First to start recording, last to stop

– Used for playback to ground when no KU

• Backup #2: digital VCR at JSC, records playback orbits

• Backup #3: analog at GSFC– Degraded quality, probably not sufficient for scientific analysis

MEIDEX

D - 15

Calibration

• Moon calibration:– Shuttle moon pointing maneuver

– Moon entering the Xybion FOV

– Maintain a 2-5 deg. Deadband for 10 min.

– Problem:

• Alignment of experiment with the -ZLV

• Perform an alignment check on a pre-determined target

MEIDEX

D - 16

POCC Operations

• When:– A PS is not available

– Target of opportunities

• What is required:– Open the HMDA (the door…)

– AFD recording

– Real-time video downlink

MEIDEX

D - 17

Anomalies

• Possible reasons:– Failures (use redundancy, camera definitions)

– Special scientific input (filter change)

• Pre-defined from ground in the Ex. Pkg.