N A S A G O D D A R D S P A C E F L I G H T C E N T E R

I n t e g r a t e d D e s i g n C a p a b i l i t y / I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y

MAXIM Periscope Module

Mechanical Systems

Joe Pellicciotti

Mick Correia

Dave Palace

25 April 2003

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y

Mechanical Systems, p2Final Version

25 April 2003MAXIM Periscope Module

Mechanical Design Requirements

• Mass Efficiency– 2 periscope assemblies (2 input apertures) on a single bench– Trade study on bench materials– Trade 2 bench assemblies in a single enclosure

• Thermal design will provide Delta-T stability of the periscope to be better than 0.020K

– Select materials and design configuration that will meet alignment stability requirements at this temperature stability

– Stability required for ~3 hour observations• Mechanical Stability Requirements:

DOF X Y Z ØX

(Yaw)

ØY

(Pitch)

ØZ

(Roll)

Mirror Stability Tolerance

±1.7nm

±0.3mm

±94.7nm

±6.9arcmin

±2.3marcsec

±0.13arcsec

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Mechanical Systems, p3Final Version

25 April 2003MAXIM Periscope Module

Periscope Assembly

Entrance Aperture(Thermal Collimator)

Shutter Mechanism(one for each aperture)

Assy. Kinematic Mounts (3)

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Mechanical Systems, p4Final Version

25 April 2003MAXIM Periscope Module

Periscope Assembly (cont.)

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y

Mechanical Systems, p5Final Version

25 April 2003MAXIM Periscope Module

Optical Bench & Mirrors

Pitch

Roll

Translate

Translate

Mirror #1Mirror #2

Mirror #3

Mirror #4

3 DOF Mechanism

1 DOF Mechanism

Main Optical BenchMirrors(300mm x 200mm x 50mm)

EntranceAperture

ExitAperture

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Mechanical Systems, p6Final Version

25 April 2003MAXIM Periscope Module

Optical Bench Details

Secondary Bench Flexures (4/Bench)

Main Optical Bench

SecondaryOptical Bench(Mirrors 2 & 3)

Secondary BenchTranslation Mechanism

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Mechanical Systems, p7Final Version

25 April 2003MAXIM Periscope Module

Launch Configuration Layout

Delta IV ø5m x L14.3m 24 Free Flyer Satellites (4 Apertures ea.)1 Hub Satellite (12 Apertures)1 Detector Satellite

Ø4.75m

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Mechanical Systems, p8Final Version

25 April 2003MAXIM Periscope Module

Optical Bench Material Options

Material

Main Optical Bench Mass

(Kg)

Potential Mass Optimization

(% Reduction)

Required Thermal

Stability† (°K)

Mfg. Cost‡

Mfg. Risk‡

Pros Cons

Super Invar 22.2 30% 0.0581 4 4 Great thermal stability

Heavy & tricky to machine

SiC (Sintered) 8.5 50% 0.0087 5 5 Very light weight & good thermal stability

Relatively new material, cost high & mfg. risks unknown

Titanium (6Al-4V) 12.4 23% 0.0020 3 1 Light weight & stiff

Thermal stability reqmt is low

Beryllium 4.5 45% 0.0015 5 5 Extremely light weight

Thermal stability reqmt is low & mfg costs are high

Composite (GFRP) w/metallic support blocks

5.7 20% 0.1744

(CME Shrinkage ~3.9µm in X-Dir)

3 3 Extremely light weight & great thermal stability

Moisture abs. distortion unknown – may require more mechanisms.

Low thermal conduction (high gradient)

† Thermal Stability based on bulk temperature change‡ Cost & Mfg Risk rated from 1 to 5 with 5 being the highest

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y

Mechanical Systems, p9Final Version

25 April 2003MAXIM Periscope Module

Mass Breakdown – Invar Bench

MAXIM Subsystem / Component Mass ea Qty Cont. Total

Description (Kg) (Kg) Mass &25% Cont (Kg)

Periscope Assy (2 Input Apertures)Enclosure Structure (M55J Comp) 5.0 1 1.3 6.3Enclosure Kinematic Mounts 0.5 3 0.4 1.9Main Optical Bench Str. (Super Invar) 22.2 1 5.6 27.8Bench Str to Enclosure Flexure Mts 0.2 3 0.2 0.8Secondary Optical Bench (Super Invar) 5.2 2 2.6 13.0Secondary Bench Flexures (Ti) 0.1 8 0.2 1.0Mirror (ULE - 300mm x 200mm x 50mm) 2.1 8 4.2 21.0Fixed Mirror Mounts (Ti) 0.4 6 0.6 2.9Thermal Precolumnator 0.5 4 0.5 2.53 DOF Mirror Mechanism 3.4 2 1.7 8.51 DOF Translator Mirror Mech 1.6 2 0.8 4.0Shutter Mechanism 1.0 2 0.5 2.5Metrology (Eddy Current & Encoders) 1.0 2 0.5 2.5Harness 0.5 1 0.1 0.6Misc. Hardware (5% of Str) 1.4 1 0.3 1.7

Periscope Assy Mass Props 77.4 1 19.4 96.8

Periscope Support ComponentsMechanism Drive Elec. (MDE) & Housekeeping Elec. 7.0 1 1.8 8.8Harness 0.5 1 0.1 0.6Misc. Hardware 1.0 1 0.3 1.3

Periscope Support Mass Props 8.5 1 2.1 10.6

MAXIM Periscope System Mass Props 85.9 21.5 107.4

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Mechanical Systems, p10Final Version

25 April 2003MAXIM Periscope Module

Summary, Recommendations & Future Work

• Thermal stability requirement on the optical bench may be reduced if observation times are short (hours vs. days)

• Composite bench may require additional mechanisms or stroke to compensate for moisture evaporation distortions

• Baseline bench configuration has room for additional mass optimization

Future Work:• Determine the allowable gradient through the optical

bench that will meet distortion requirements.• Perform detailed trade study on optical bench materials

– Thermal / Structural analysis– Launch Dynamics analysis– Investigate GFRP bench as next best candidate

• Include methods to limit moisture absorbtion

• Possibly combine 2 main benches into a single enclosure (4 entrance apertures) to reduce overall mass and volume

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y

Mechanical Systems, p11Final Version

25 April 2003MAXIM Periscope Module

Back-up Information

• Flexure system option for secondary Mount

I n s t r u m e n t S y n t h e s i s & A n a l y s i s L a b o r a t o r y

Mechanical Systems, p12Final Version

25 April 2003MAXIM Periscope Module

Secondary Bench TranslationalPositioning System Kinematics

Reference & Acknowledgement:Nicholas G. Dagalakis, John A. Kramar, Edward Amatucci, and Robert Bunch, “Kinematic Modeling and Analysis of a Planar Micro-Positioner,” National Institute of Standards and Technology, Gaithersburg, Maryland 20899

X

Y

AC

A1 A2

A1t A2t

a1

c2

c1t c2t

b1 b2

b2tb1t

a2

c1

MS

Wy

L1y L2y

H1y H2y

• System Provides smooth linear motion

• Negligible cross-axis motion