Dave Akin, Lockheed Martin AKIN@LMSAL.COM 650-424-3989 HMI Mechanisms Dave Akin, Lockheed Martin AKIN@LMSAL.COM 650-424-3989 Revision K

HMI Mechanisms Hollow-Core Motors (7 motors) Shutters (2 motors) Each motor rotates an optical element Shutters (2 motors) One for each CCD Control exposure to CCD Focus Wheels (2 motors) Adjust focus by placing various thickness glass into optical path Calibration mode places 2 lenses into optical path Front Door (2 motors) Open and close aperture door Alignment Mechanism (2 motors) Move (point) instrument with respect to spacecraft

HMI Mechanism Locations

Hollow-Core Motor Requirements Design Life (5-year mission): 80 M operations Repeatability: 20 arc-seconds (1 sigma) Absolute Stopping Accuracy: ±8 arc-minutes Clear Aperture: > 1.340 inches (34 mm) Operating Temperature: 15 to 35 C Survival Temperature: -10 to 50 C Time to Move: 180 degree move in 1 second

Similar Motor from Program D

Hollow-Core Motor Section RED = ROTATING PARTS

Hollow-Core Motor Design Motor: H.Magnetics Brushless DC Motor Bearing: MPB Size S2532 Lubrication: Nye 2001B (vacuum impregnated) Retainer: Phenolic, one-piece Preload: Back-to-back matched pair; 10 – 15 lb. Mass: < 500 g Energy dissipated by Hollow-Core Motors (Joules): Windings: 0.0037 + 0.0015 * degrees moved Encoder: 0.0010 + 0.0001 * degrees moved Total: 0.0047 + 0.0016 * degrees moved (results of computer simulation) Torque 34 oz-in available (stall) Bearing Friction: < 2 oz-in Magnetic Detent: TBD (1 to 6 oz-in, based on prototype testing) Hysteresis Drag Torque: < 1 oz-in

Hollow-Core Motor Testing Prototype Operate with 2 different rotors Skewed magnets Like Program D motor Minimal magnetic detent Straight magnets Unknown magnetic detent Reduced eddy current losses Pick design with best repeatability Operate motors in thermal chamber (-20 to 60 C) Repeatability test with external encoder (all positions) Repeatability test with theodolite (fewer positions, higher resolution than encoder) Torque margin verification (operate with reduced voltage) Friction & Cogging (measure with torque watch) Measure disturbance torque vs. time Measure Resistance, BEMF (Back ElectroMotive Force) , Damping and Friction Coefficients IRED (Infrared Emitting Diode) intensity margin

Hollow-Core Motor Testing Flight Motors Repeatability test with external encoder (all positions) Torque margin verification (operate with reduced voltage) Friction & Cogging (measure with torque watch) Measure Resistance, BEMF, Damping and Friction Coefficients IRED intensity margin

Hollow-Core Motor Life Test 5-year expected use is 80 M operations Vacuum life test 2 identical motors to minimum 160 M operations each Life Test Motors: Assembled using detailed assembly procedures (same as used for flight motors) Functional Tests (same as flight motors) Vibration (GEVS level) (GEVS = GENERAL ENVIRONMENTAL VERIFICATION SPECIFICATION FOR STS & ELV PAYLOADS, SUBSYSTEMS, AND COMPONENTS) Thermal (-10 to 50 C in air) Vacuum Life Test Temperature held at 30 C with heaters Mechanism health is trended throughout the test Disassemble & Inspect Refurbish to become Flight Spares (new bearings)

Hollow-Core Motor - Heritage MDI Michelson Tuning Motors Single, Magnetically Preloaded Bearing TRACE Guide Telescope Motors Identical to MDI Tuning Motors Program D Polarization Modulator Similar Bearing Design (slight size difference) Same Lubricant, Same Retainer Program F Hollow-Core Motor Braycote 600, Teflon Toroids

Focus Wheel Requirements Design Life (5-year mission): 2 M Operations Operating Temperature: 15 to 25 C Survival Temperature: -10 to 50 C Optical Beam Diameter: 1.004” (25.5 mm) Optical Elements: Wheel 1 Wheel 2 Blank Position Blank Position 10.2 mm thick focus block 2.55 mm thick focus block 6.8 mm thick focus block 1.7 mm thick focus block 3.4 mm thick focus block 0.85 mm thick focus block 6.8 mm thick lens 5 mm thick lens

Focus Wheel Design 5 positions per wheel Order of optics in wheels selected for best balance Wheels are not otherwise balanced 1.190” Diameter Opening Bearings Timken MPB SR4FCHH7 Lubricant: Braycote 600 Grease Preload: 3 lb. Mass: < 300 grams Torque 20 oz-in available (stall) Bearing Friction: < 1 oz-in Magnetic Detent: ~ 6 oz-in Hysteresis Drag Torque: < 1 oz-in

Filter Wheel

Focus Wheel Layout

Focus Wheel Testing Prototype Flight Operate in thermal chamber (-20 to 60 C) Repeatability (external encoder) Torque margin verification (operate with reduced voltage) Friction & Cogging (measure with torque watch) Measure disturbance torque vs. time Measure Resistance, BEMF, Damping and Friction Coefficients IRED intensity margin Flight

Focus Wheel - Heritage MDI TRACE Program C Program B Program E 68 M operation vacuum life test without failure 3 wheels functioning without failure in the MDI instrument since 1995 TRACE 5 ½ years of on-orbit operations without failure Program C 32 M exposure vacuum life test without failure 4 filter wheels are integrated to 2 flight SXI instruments Program B Prototype filter wheel has undergone thermal & vibration testing 2 flight filter wheels are integrated to the flight instrument Flight instrument has undergone environmental testing Program E 2 wheels are integrated to the flight instrument; testing is in-progress Program D 4 wheels are integrated to the flight instrument; testing is in-progress

Shutter Requirements Design Life: 40 M Exposures Operating Temperature: 15 to 25 C Survival Temperature: -10 to 50 C Performance Requirements: Minimum exposure: 50 ms Nominal exposure: ~250 ms Maximum exposure: 10 s (for LTC and darks) Exposure Measurement Resolution: 2 μs Repeatability: 10 μs standard deviation (one sigma) Uniformity: 250 μs (across field of view)

Shutter Design Motor: Kollmorgen RB-00502-N02 Bearing Design is TBD (based on outcome of life test) Baseline Design: Nye 2001B lubricant Phenolic retainer 0.9 lb. spring preload Mechanical design is similar to Program D shutters Thicker encoder housing for radiation shielding Energy: Joules per exposure = 0.043 + 0.045 * exposure in seconds (computer simulation) Mass: ~125 grams (motor & blade) Torque 2.44 oz-in available (stall) Bearing Friction: < 0.2 oz-in Magnetic Detent: ~ 0.5 oz-in Hysteresis Drag Torque: < 0.2 oz-in

Shutter Section RED = ROTATING PARTS

Shutter Motor Exploded View RED = ROTATING PARTS

Shutter Operation Clockwise Operation Shown 2 Moves for each exposure 120 degree move to open 240 degrees to close

Shutter Testing Prototype Flight Operate in thermal chamber (-20 to 60 C) Exposure repeatability test Torque margin verification (operate with reduced voltage) Friction & Cogging (measure with torque watch) Measure disturbance torque vs. time Measure Resistance, BEMF, Damping and Friction Coefficients IRED intensity margin Flight

Shutter Performance Testing Prototype HMI Shutter 1000 Consecutive Exposures 100.352 ms Exposure Setting Vary Voltage from 14.9 to 15.0 every 100 exposures 14.9 V 15 V

Shutter Life Test 5-year expected use is 40 M exposures Life test 4 shutters: Lubricant Retainer Preload Bearing 1) Bray 815Z Crown 0.9 lb. SR3FCHH7P28LY303 2) Nye 2001B Phenolic 0.5 lb. N298-000 (custom) 3) Nye 2001B Phenolic 0.9 lb. N298-000 (custom) 4) Nye 2001B Minapore 0.9 lb. N298-800 (custom) 80 M exposure (each shutter) life test: Assemble using detailed assembly procedures (same as used for flight motors) Functional Tests (same as flight motors) Thermal (-10 to 50 C in air) Vibration (GEVS level) Vacuum Life Test Temperature held at 30 C with heaters Mechanism health is trended throughout the test Disassemble & Inspect Bearings

Shutter Heritage SXT MDI TRACE Program C Program B Program F Program E In orbit since 1991 8 M on-orbit exposures without failure MDI 68 M operations without failure (vacuum life test) ~ 70 M on-orbit operations without failure TRACE 12.5 M on-orbit exposures without failure Program C 33 M operations without failure (vacuum life test) 2 Shutters integrated to 2 flight SXI Instruments Program B Shutter integrated to flight instrument; undergone environmental testing Program F Life test in progress Program E Integrated to the flight instrument; testing in-progress Program D 2 Shutters integrated to the flight instrument; testing in-progress

Door Requirements Mechanism must open the door with any plausible single-point failure Door Opens 170  5 Degrees Design Life: 1000 Cycles Operates in Any Orientation in 1G Operating Temperature: 0 to 40 C Survival Temperature: -20 to 65 C

HMI Door

Door Assembly

Door Design Spring to hold door shut: Actuator: Lubricants: SPEC T051-360-406R 1.5 in-lb closed 2.9 in-lb opened Actuator: Made by CDA Intercorp Torque: 6 lb-in (50:1 gearhead, 100 pps) 12 steps per motor revolution 600 steps per worm revolution 11,333 steps to open door (113 seconds @ 100 pps) Lubricants: Actuator Gearhead: Braycote 600 Worm & Wheel: Pennzane Grease

Door Operation One motor is normally used to open/close the door. Nothing prevents both motors from being used at once. Each motor operates independently from the other. Motor runs until either: a) Limit switch is activated b) Programmed maximum number of steps have been sent Drive electronics stores the number of steps required to open or close the door. There are override commands in case a limit switch fails closed. Door can function with either a failed-open, or failed-closed limit switch. Door may be opened to less than the nominal 170 degrees.

Door Testing Brassboard Mechanism Flight Mechanism Various Functional Tests Torque Margin Verification Operate in Thermal Chamber (-20 to 70 C) Vibration with Structural Model Flight Mechanism Environmental Tests with Flight Instrument

Door Heritage Similar to MDI Door Differences: Either Motor Can Open Door Spring Holds Door Closed Door is Balanced Differences: HMI uses Step Motors from CDA Intercorp MDI used Brushless DC Motors from Inland Motor HMI uses CDA Gearhead (integral with motor) MDI used Gearhead from PIC

Alignment Mechanism Requirements On-Orbit Range: ± 200 arc-seconds Range for Ground Testing: ± 600 arc-seconds Step Size: 2 arc-seconds maximum Design Life: 1 M steps Operating Temperature: 0 to 40 C Survival Temperature: -10 to 50 C

Alignment Mechanism Design Actuator: Made by CDA Intercorp Maximum Operating Force: 10 lb. Maximum Non-Operating Force: 250 lb. 12 steps per motor revolution 25:1 Gearhead Ratio Step Resolution: 0.00033 inches Lubricants: Actuator Gearhead: Braycote 600 Leadscrew: Braycote 600 Position Feedback: Each lever has a 2-channel optical encoder One channel indicates if the mechanism is within its operating range Other channel indicates which half of the range the mechanism is in

Alignment Mechanism

Alignment Mechanism

Alignment Mechanism

Alignment Mechanism

Alignment Mechanism Range

Alignment Mechanism Testing Brassboard Mechanism Various Functional Tests Torque Margin Verification Vibration with Structural Model Flight Mechanism Environmental Tests with Flight Instrument

Alignment Mechanism Heritage Similar to MDI Alignment Mechanism Differences: HMI uses step motors from CDA Intercorp MDI used Kollmorgen motors HMI has gearhead between leadscrew & motor MDI had motor directly drive the leadscrew HMI uses optical sensor for position feedback MDI used microswitches & potentiometers Optical limit switch Same electronic parts as other encoders Same design as: TRACE Focus Mechanism Program D Slit Scan Mechanism

Disturbance Torque Focus Wheel Hollow-Core Motor Shutter Front Door 40 oz-in (computer simulation) Hollow-Core Motor 15 oz-in (computer simulation) Shutter 3 oz-in (computer simulation) Front Door Disturbance < 2 oz-in Mechanism is seldom used Alignment Mechanism

Summary Peer review held 9/17/2003 Hollow-Core Motors Shutters Received comments from Ken Lee & John Van Blarcom (NASA) as well as from several Lockheed Martin participants Hollow-Core Motors Prototype motor on-order; expected 11/25/2003 Life test planned to start spring 2004 Shutters One for each CCD Life test planned to start January 2004 Focus Wheels Detailed drawings in-process Front Door Alignment Mechanism 2 actuators on-order (due 3/10/2004)