teoa m2 optical assembly fabrication - dkist · 2020-01-22 · l-3 communications proprietary jay...

L-3 Communications Proprietary

Jay Schwartz 2/21/2012

TEOA M2 Optical Assembly

Fabrication

This technical data is controlled under the International Traffic in Arms Regulations (ITAR) and may not be exported to a Foreign

Person, either in the U.S. or abroad, without proper authorization by the U.S. Department of State.

ITAR Controlled Document

TEOA M2 Optical Assembly Fabrication Outline

M2 Optical Assembly Fabrication

– Manufacturing Overview

– Polishing Overview

M2 Optical Assembly Metrology

– Primary Optical Test Method

– Redundant Optical Test Method

– Profilometry Test Method

– Metrology Tolerance Analysis

– Metrology Setup Alignment

M2 Optical Assembly Shipping Plan

Preliminary Verification Matrix

Risk Summary & Mitigation Plan

ITAR Controlled Document 2


M2 Optical Assembly Manufacturing

Jay Schwartz

Program Manager - SSG

3

M2 Optical Assembly Manufacturing Process Flow

4

Mirror Tooling

Design

Procure

Tooling Cast Mirror

Substrate Sintering

Furnace Run

Machine Sintered

Substrate

Full Density

Furnace Run

Final

Machining Ship to

Tinsley

Grind Unclad Optical

Surface (~1 micron of

profile)

Ship to Cladding

Vendor

Deposit Protected

Silver Reflective

Coating

Ship to

Tinsley

Post Coating

Metrology/FAT

Delivery to Brashear for

TEOA Integration

Procure Shipping Container

Optical Metrology

Bond

Bipods Thermal

Cycle

Procure Bipods and Transfer Plate

Ship to Silicon Cladding

Vendor Deposit Silicon

Cladding

Final Polish Optical

Surface

Ship to

Tinsley

Ship to

Coating

Vendor

M2 SiC Substrate Fabrication

5


M2 Optical Assembly Polishing Overview

A. Magruder

2/21/2012

M2 Optical Assembly Polishing Overview-Tinsley

Computer controlled grind and polishing tools used in conjunction with metrology to

achieve overall surface figure, high spatial frequency figure and surface roughness.

Grind asphere to within ~1 micron P-V in bare SiC surface.

Final grind and polish performed in silicon cladding


M2 Optical Assembly Polishing Methodology

To meet Encircled Energy Budget, Tinsley will polish M2

surface to a nominal 40 deg telescope zenith angle.

– Tinsley will polish to a software null surface figure that will be

provided from an finite element analysis model.

– Gravity Induced Mount Error caused ~ 40 nm of 3 theta

(trefoil) surface error at horizontal LOS.

– This predictable error can be removed using localized

polishing to a software null.

Tinsley has a history of polishing Spherical and Aspheric

mirrors to extreme precision utilizing Computer Controlled

Optical Surfacing (CCOS) to data provided through

interferometric null testing.

This capability has been applied to optical surfaces that

do not have convenient null test configurations through

the use of a software null.

To accomplish this, an optic is measured relative to a

reference wavefront that provides a near-null

interferogram. This interferogram is then compared to the

expected interferogram for the desired amorphous surface

in test.

8 2/15/2012

Example of desired departure from a null

interferogram

Example of null test setup

Software Null Example #1 JWST TM Software Null

9

In 2011, Tinsley completed the James Webb Space Telescope (JWST) beryllium Mirrors

and Mirror Segments. Each was tested and fabricated in an ambient environment with a

software null expected to yield a nominal prescription in a cryogenic environment.

The 0.7m JWST TM software null had a magnitude of 66nm RMS and an irregular

shape.

The desired mirror surface was replicated to within 5 nm RMS of the nominal figure and

this result was verified through testing in cryogenic conditions.

Surface map of desired surface figure error:

390nm P-V, 66nm RMS from aspheric

prescription

Departure from desired surface:

79nm P-V, 4.3 nm RMS

For aspheric mirrors with slight departure from best fit sphere, this technique can be

used to reduce the cost and lead time associated with diffractive elements or test optics.

The optic is tested against a spherical wavefront. The test results are compared to an

expected deviation and the resulting data is used to manufacture the desired asphere.

This technique was implemented on the below displayed convex hyperboloid with

147nm RMS departure from best fit sphere.

10

Synthetic Fringe map of desired surface figure

error: 535nm P-V, 147nm RMS from spherical

reference wavefront

Departure from desired surface over Clear

Aperture: 13.5nm P-V, 1.4 nm RMS

Software Null Example #2 Mild Asphere Departure


M2 Optical Assembly Metrology

Adam Magruder

L-3 IOS Tinsley

11

M2 Metrology - Tinsley

L-3 IOS Tinsley plans to perform three measurements to verify prescription and

irregularity.

The optic will be tested

– (1) using a computer-generated hologram (CGH)

– (2) in a conjugate configuration

– (3) using profilometry

CGH testing allows the M2 Mirror to be easily sheared rotationally in gravity which is

attractive in that it allows measurement of the mount-induced surface distortion.

The aspheric departure of the M2 Mirror is relatively low and the CGH has a

relatively routine design. This will facilitate design and fabrication of the CGH and

reduces the effect of printing errors which improves the accuracy of the projected

wave front on the part. These residual errors are accounted for in our error budget.


M2 Optical Prescription Parameters and Tolerances

The ATST M2 Mirror concave off-axis ellipsoid has the optical prescription

parameters indicated in Table below.


Parameter Nominal Tolerance

Radius 2081.25885 mm ± 1mm

Off Axis Distance 594.312 mm ± 0.2mm

Clocking 0 ±1 Arc Minute

Surface Figure Error 0 25 nm RMS

M2 Primary Optical Test Method CGH Layout Design

The CGH test layout is shown below. The CGH is expected to be placed 315mm

from the Cat’s eye with the mirror located approximately 2.2m from the cat’s eye.

These spacings and alignments will be set using the CGH alignment features as

described in the Tolerance Analysis and Metrology Setup Alignment sections.


The primary buyoff methods of profilometry and the CGH based interferometric test

will be complimented by conjugate testing of the M2 Mirror, with an interferometer at

the far catseye, and an Spherically Mounted Reflector (SMR) at the near catseye

(Figure 1). The two conjugates are located at approximately 1.2 and 7.8m,

respectively, from the M2 Mirror vertex. This test will be set up on a 20 x 5 foot

optical table with a fold flat to account for the full long conjugate length


M2 Redundant Test Method Conjugate Testing


Fold

Flat

M2

20x5 foot table Interferometer

The test beam is approximately F/11. Data will be collected first as a full aperture

measurement to quantify prescription and low order shape, and then the test beam

will be zoomed in to 4x, to interrogate ~Ø150mm subapertures to quantify mid

frequency surface figure. These measurements will measure M2 Mirror spatial

periods from 75mm down to approximately 1.2mm. Phase measuring microscopy

will be used to measure spatial periods from below 0.15mm to as long as 2.5mm,

providing validating overlap with the subaperture measurements of high spatial

frequency surface structure to verify the high spatial frequency surface figure

accuracy requirement.


A laser tracker will then be used to directly measure the positions of the long

conjugate, the short conjugate and the mirror alignment targets which will give the

Radius of curvature and Conic constant.

The Off Axis Distance and Clocking relative to the alignment targets will be

measured in the CGH based interferometric test as a secondary method. This will

use the alignment targets as retro reflectors that position the optic relative to the

CGH and cat’s eye



Optical Testing Heritage JWST Tertiary – Conjugate Test

L-3 IOS Tinsley used a conjugate test to verify the optical prescription of the JWST

tertiary.

The far conjugate of the JWST tertiary mirror is located 16m from the mirror, forcing

the test setup to be folded to fit within available facility space.

The JWST tertiary conjugate test was designed as a prescription verification only

(radius, conic, OAD) and extra precautions were not taken to achieve the best

possible surface figure error accuracy.

Nevertheless, the conjugate test measurements achieved 15nm RMS agreement

with the CGH center of curvature test ,proving the value of these two independent

metrology approaches in cross-checking each other.

This agreement can be improved through calibration of the transmission sphere,

using an improved SMR at the short conjugate, and controlling air turbulence each of

which is described in the Tolerance Analysis section.


Test Methodology Heritage to JWST Tertiary (1)

L-3 IOS Tinsley used the three optical test methods (CGH center of curvature,

conjugate testing, and optical profilometry) in 2010 to verify the surface figure

accuracy of the JWST tertiary mirror. The primary test method was CGH center of

curvature. L-3 IOS Tinsley delivered the JWST tertiary mirror with a surface error of

4.3 nm RMS.


Optical Testing Heritage JWST Tertiary – Surface Error

Figure below shows the difference between CGH and Conjugate Testing of the

JWST Tertiary was < 15 nm RMS


Optical Testing Heritage JWST Tertiary - CGH / Conjugate Test Comparison

M2 Profilometry Test Method Heritage JWST Tertiary

L-3 IOS Tinsley used profilometry to cross-check the optical prescription on the

JWST tertiary.

Our Profilometry measurements are accurate for low order shape with a 3σ

confidence to 490 nm P-V. This uncertainty is used to bound the potential errors in

OAD, Clocking, and Radius.

This analysis can be seen in the Tolerance Analysis section. The profilometers are

also accurate in mid frequency surface figure to 100 nm RMS as seen below in a

measurement of the JWST Tertiary Mirror.

Although this did not act as a fully redundant quantification of the RMS surface

figure error requirement, it did show that there were no major errors with the optical

tests.


M2 Profilometry Test Method Heritage JWST Tertiary

Profilometry of the JWST tertiary mirror was repeatable to 100 nm RMS.



Adam Magruder

L-3 IOS Tinsley

M2 Optical Assembly

Metrology Tolerance Analysis


M2 Optical Test Tolerance Overview

The key parameters for Tolerance Analysis for the ATST M2 Mirror are the radius of

curvature, the rotation relative to the M2 Assembly (clocking), the off axis distance,

and the surface figure error. The Table below summarizes the sensitivity of sag

error to variation of these key parameters within their tolerance band.


Parameter Nominal Tolerance P-V Resulting Sag

Error

Radius 2081.25885 mm ± 1mm 11.16 μm

Off Axis Distance 594.312 mm ± 0.2mm 0.82 μm

Clocking 0 ±1 Arc Minute 0.70 μm

Surface Figure

Error 0 25 nm RMS

M2 CGH Test Method Tolerances

CGH Based Interferometry will serve as the primary buyoff method for surface figure

error and as a redundant method for Off Axis Distance and Clocking. This test uses

a CGH to modify a spherical wavefront to match the aspheric prescription of the

mirror. We will align the mirror in test to match the positions of the alignment targets

on the mirror to pencil beams that will be emitted from the CGH. These beams will

retro reflect off of the alignment targets, and produce fringes in the interferometer

which we will use to position the mirror in X and Y decenter as well as clocking to the

CGH. For the JWST TM this alignment method was sufficient to align the mirror to

0.33 arc minutes in clocking and 0.1 mm of centration, and similar uncertainty is

expected on the ATST M2. The Z position of the part will then be floated and

residual alignment aberrations are accounted for in our error budget. Figure 1 is our

initial error budget analysis for the surface figure error of the ATST M2.

Each error source is assigned a sensitivity which describes the effect of a

perturbation of this term on our knowledge of the optical surface and a tolerance

which bounds the size of the perturbation in test. The tolerances in this analysis are

based on as-measured tolerances from the JWST TM CGH test and will be re-

quantified for the ATST M2. The sensitivities are based on an initial design for the

ATST M2 by Diffraction International and will be updated when the final design is

complete.


The conjugate test will also provide a secondary measurement of the Surface figure

error. This measurement will have errors associated with air turbulence over the

long path length, errors in the surface of the retro ball placed at the short conjugate,

and errors in the transmission sphere on the interferometer.

Great care is taken to reduce the air turbulence and thermal gradients by performing

the measurements in our large optics metrology lab equipped with a constant

unidirectional air flow. This serves to keep air moving through the test which

prevents pockets of heat from forming and disrupting the measurement. Since

Tinsley is operational 24 hours per day the final tests can be set up to run through

during the night shifts which additionally reduces turbulence and thermal variations.

For the Retro Ball at the short conjugate, we will use a ruby ball coated in silver to

provide a high precision optical surface. These balls are spherical to within ~60nm

P-V which is typically due to surface defects on the ball. The specific ball to be used

will be measured and quantified for the Conjugate test Error budget. This will not

contribute significantly to the 25nm RMS specification.

Transmission sphere will be calibrated and subtracted using a shearing algorithm

and a calibration sphere.


M2 Conjugate Test Method Tolerances

M2 Profilometry Test Method Tolerances

The primary buyoff method for Radius, Off Axis Distance, and Clocking will be with

the Leitz PMM_C Profilometer.

Well designed profilometry fixtures which allow for repeatable and stable placements

of our test optics.

Careful calibrations and analysis to remove errors due to thermal drift and spurious

data points allow very precise measurements of optical prescription on our Leitz

PMM_C profilometer.

Gravity deflection and thermal gradients are also important considerations in

characterization of prescription, and can be calculated and compensated for if

necessary.


Table shows repeated measurements of a

concave sphere of radius 1757.127mm

and diameter 620mm. The Sphere is

measured using an interferometer with a

DMI, and is measured with the Leitz

PMM_C. The radius is compared to find

the uncertainty of the profilometer for low

order shape. Out of 15 measurements

the maximum Radius discrepancy is .0209

mm which translates to a sag error of

333nm P-V using the sag equation of a

sphere.

The 99% confidence deviation is the

average deviation plus 3σ, .002 mm +

3*.0096mm.

This yields a three sigma confidence of

0.0308mm or 490nm P-V.


Measurement

File Name

DMI

MEASURED

Radius of

Sphere

Leitz PMM,

Measured

Radius (mm) Delta (mm)

Average of

Group

Average

Delta of

Group

PRBRUN1 1757.127 1757.1235 0.0035

PRBRUN2 1757.127 1757.1198 0.0072

PRBRUN3 1757.127 1757.1261 0.0009 1757.1231 0.0039

XMRUN1 1757.127 1757.1183 0.0087

XMRUN2 1757.127 1757.1061 0.0209

XMRUN3 1757.127 1757.1231 0.0039 1757.1159 0.0111

XPRUN1 1757.127 1757.1257 0.0013

XPRUN2 1757.127 1757.1141 0.0129

XPRUN3 1757.127 1757.1477 -0.0207 1757.1292 -0.0022

YPRUN1 1757.127 1757.1225 0.0045

YPRUN2 1757.127 1757.1341 -0.0071

YPRUN3 1757.127 1757.1329 -0.0059 1757.1298 -0.0028

YMRUN1 1757.127 1757.1329 -0.0059

YMRUN2 1757.127 1757.1248 0.0022

YMRUN3 1757.127 1757.1233 0.0037 1757.1270 0.0000

Average 1757.1250 0.0043

Standard Deviation 0.0096 0.0113 Range, %

Maximum 1757.1477 0.0209 0.0012%

Minumum 1757.1061 -0.0207 -0.0012%

Table: Profilometry repeatability and accuracy

This is considered to be the uncertainty in low order figure in our profilometer

and is applied to deviations in Radius, Off Axis Distance, and Clocking for the

ATST M2

M2 Profilometry Test Method Tolerances

M2 CGH Test Method Tolerances

This analysis of surface figure error

shows a total potential error of 5.85

nm RMS. This is removed in

quadrature from the total tolerance

of 25nm RMS to leave a part

fabrication residual of 24.3 nm

RMS. This means that when these

tolerances are met and we measure

a final value less than 24.3 nm

RMS, we will have confidence that

the true value is below 25nm.

In order to meet these tolerances a

careful fine alignment of the

interferometer, CGH, and part under

test is needed. The equipment and

methods used for this alignment are

described in the Metrology Setup

Alignment plans section.


# meas Tolerance unit

Tinsley Specification

Fixed Metrology

Metrology (Estimated)

Optical design residual 1 fringes

CGH Fabrication

Substrate Thickness 1 0.08 mm 0.22

Substrate Index 1 0.0001 0.00

Substrate Wedge TLA 1 0.10 frg 0.03

Substrate Wedge TLB 1 0.10 frg 0.02

Substrate Power 1 0.14 frg 0.91

E-beam Registration 1 0.07 um 0.70

Substrate TWF 1 4.75 nm 2.06

Encoding and Digitization 1 0.05 frg 0.49

Test Alignment

Cat's Eye X 1 0.002 mm 0.142456

Cat's Eye Y 1 0.002 mm 0.22223

Cat's Eye Z 1 0.02 mm 0.711769

Horizontal Fringes 8 3.00 frg 0.112424

Vertical Fringes 8 3.00 frg 0.072152

Power Fringes 8 1.00 frg 2.265028

Part asphere R 1 0.30 mm 3.609239

Interferometer

Source Zernike #1 1 2.50 wv 0


Source Zernike #3 1 5.00 wv 0.03164






transmission sphere irregularity 8 1.00 0.542552

Wavelength 1 0.01 nm 1.273194

Data Processing

Data Registration fid loc 1 1.00 test 0.143402

CGH Null scale 1 0.01 N.A. 0.377534

CGH Null decenter X 1 0.01 Ø 0.272732

CGH Null decenter Y 1 0.01 Ø 0.464594

CGH Null clocking 1 0.60 deg 0.121306

Metrology Reserve

Thermal Stability

Axial Gradient 1 0.03 K

Horizontal Gradient 1 0.10 K

Vertical Gradient 1 0.10 K

Thermal Soak 1 2.20 K

Part Fabrication Residual

0

2.487483945

0.684135204

24.3054745

0.674476249

0.474369081

1.818248431

1.620519398

1.901122366

0

1.384520165

4.330254288

RMS Surf Error (nm)

4.97496789

5.851829564

25

M2 Conjugate Test Method Tolerances

The conjugate test will serve as the redundant buyoff method for Surface Figure

Error, Radius of Curvature, and Conic Constant. In this test the interferometer, part

under test, and a retro reflecting tooling ball will be placed on a 20x5 foot table with a

fold flat to account for the full long conjugate length. They will be aligned to best null

and a laser tracker will be used to measure the spacing between an SMR placed at

Cat’s eye, the parent vertex of the part through the alignment datums, and an SMR

placed at the short conjugate. This spacing will be reported along with the residual

measured wave front to show the Conic Constant, Radius of Curvature, and Surface

Figure Error.

In order to ensure that the Radius and Conic fall within 1mm of nominal Radius and

the associated shift in conic through, the short conjugate must be known with an

accuracy of .7mm and the long conjugate must be known with an accuracy of

1.435mm as seen below in figure 2. These uncertainties are large relative to the

abilities of the laser tracker and should not represent a technical challenge. For the

JWST TM, a similar conjugate test was performed. The uncertainties in the

measured conjugate locations for that test were .035mm for the long conjugate and

.018mm for the short conjugate. The agreement between this test and our primary

methods for measuring Radius and Conic were .057mm and .00012 respectively,

which would be well in the range of the ATST M2 allowed tolerances.



1.201 103

1.2006 103

1.2002 103

1.1998 103

1.1994 103

1.199 103

7.822 103

7.824 103

7.826 103

7.828 103

7.83 103

7.832 103

7.834 103

7.836 103

7.838 103

7.84 103

7.842 103

Conjugate Sensitivity

f2 (mm)

f1 (

mm

)

d2 R Rerror K Kerror d2 R Rerror K Kerror

20.699 mm

d1 R Rerror K Kerror d1 R Rerror K Kerror

21.435 mm

M2 Conjugate Test Method Sensitivity


Adam Magruder

L-3 IOS Tinsley

M2 Optical Assembly

Metrology Setup Alignment


M2 Metrology Setup Mechanical Equipment

In order to meet the tolerances laid

out in our error budget, a careful fine

alignment of the interferometer,

CGH, and part under test is needed.

Tinsley’s unique 5-axis mount, as

seen in figure 1, allows sub micron

adjustments in X, Y, and Z,

translation as well as sub micro

radian adjustments in rotation about

the X and Y axes.

The CGH will also be mounted in a

fine pitched 5 axis mount, which will

allow the error budget required 2µm

of placement accuracy of the cat’s

eye relative to the other optical

components.


Figure shows a 620mm OD Round concave optic

mounted on Tinsley’s 5-axis mount.

M2 Metrology Setup CGH Alignment

The CGH is first set to be normal to the interferometer’s outgoing beam by centering

the reflection of a collimated source off of it’s front surface on the alignment camera.

Then the transmission sphere is installed and the holograms designed into the CGH

are used for subsequent alignment.

The CGH is designed with three separate hologram patterns. The main central

hologram will hold the prescription of the asphere. This will bend the incoming

spherical wave front so that each ray contacts the surface of the M2 at normal

incidence.

A second hologram pattern is built into the exterior portion of the CGH that will give a

null return when the CGH is properly placed with respect to the cat’s eye to confirm

that this alignment tolerance is not exceeded. Since there fringes returned to the

interferometer this can be aligned to sub micron accuracy in x, y, and z centration.

A third set of holograms will create three pencil beams just outside the aperture of

the optic. These beams will converge on the alignment targets attached to the optic

and, when properly aligned, will return fringes to the interferometer which sets the X

and Y centration and clocking of the optic relative to the CGH and cat’s eye.

Finally, since the radius of curvature is controlled with the profilometer and conjugate

test, the optic is adjusted in Z translation to null out power fringes. This type of CGH

design was used on the JWST Tertiary Mirror, and has proven itself to accurately

place the CGH and Mirror relative to cat’s eye within budgeted alignment tolerances.


M2 Metrology Setup Conjugate Alignment

For the Conjugate null test the part will be similarly loaded onto our 5-axis mount on

a 20x5 foot table.

A fold flat can be used to accommodate the extra distance to the long conjugate

location.

An SMR will be placed at the short conjugate location and the mirror and short

conjugate SMR will be adjusted in X, Y, and Z decenter as well as clocking and tilt to

achieve the best null.

A laser tracker will then be used to measure the relative positions of the long and

short conjugates, and the alignment targets on the mirror.

These measurements will quantify the Conic, Radius of curvature, and residual

surface figure error within the allotted specifications. See the Tolerance Analysis

section for a further discussion of allowed alignment tolerances.


M2 Optical Assembly Shipping Plan

M2 Optical Assembly will be bolted to the

Strong Back.

The Strong Back will be mounted to a

Shipping Plate.

The Shipping Plate will be bolted to

vibration isolators attached to inside of

Pelican AL3434-1207 Single Lid Case

Pelican case will be shipped inside a

wooden shipping container with custom

foam inserts.


Preliminary Verification Matrix (1)

Paragraph Heading Specification Value Verification Method Compliance Comments

3.1.1.1 Clear Aperture CA = 620 mm I Y

3.1.1.2 Surface Figure Accuracy 24 nm RMS (tip, tilt, piston and focus (per Sandy) removed) T Y

3.1.1.3 Surface Figure Accuracy, Higher Spatial Frequency Error

6.9 nm RMS for spatial period from 0.15 mm to 15 mm T Y

3.1.1.4 Surface Imperfections

no surface imperfections of surface area larger than 5.0 square millimeters shall be allowed, and a maximum of 10.0 square millimeters shall be allowed for the summation of all defective areas within the Optical Surface T Y

3.1.1.5 Surface Roughness Less than 20 angstroms RMS (Goal less than 10 angstroms RMS) T Y

3.1.1.6 Optical Coating Brashear I A,T A,T A,T Y Brashear

3.1.2 Physical Charcteristics Drawing 164350 A I T T T T Y Drawing 164350

3.1.2.1 Alignment Targets

The accuracy in position of the target interfaces shall be within 100 microns of their reported position relative to the measured Optical Surface geometry. A,T Y

3.2.1 Interface identification and diagrams TBD ICD Y TBD ICD




3.3 System Environment Requirements I A

3.3.1 Operating A Y

3.3.1.1 Temperature -2 deg C to 22 deg C and a temperature change rate of +/- 2 deg C/hr maximum. A Y

3.3.1.2 Optical Surface Temperature Brashear Y Brashear

3.3.1.3 Humidity 0 to 70 percent relative humidity A Y

3.3.1.4 Wind Load wind speeds of up to 5 m/s (11 mph) from any direction. Y

3.3.1.5 Gravity Orientation Brashear Y Brashear

3.3.2 Non-operating A

3.3.2.1 Temperature

temperature range of -10 deg C to 27 deg C (14 deg to 81 deg F) and a temperature change rate of +/- 2 deg C/hr maximum. A Y

3.3.2.2 Humidity 0 to 95 percent relative humidity A Y

3.3.2.3 Equivalent Static Load 3 g acceleration in any direction A Y




3.3.3 Transportation Environment A Y

3.3.3.1 Altitude Range sea level to 4500 meter A Y

3.3.3.2 Temperature -20 deg to +50 deg C. A Y

3.3.3.3 Humidity 0 to 100 percent relative humidity. A Y

3.3.3.4 Wind Speed up to 70 m/s from any direction. A Y

3.3.3.5 Shock and Vibration 10 g acceleration in any direction A Y

3.4.1 Structural Design Requirements Factor of Safety of 4.0 A, I

3.4.2 Drawings and Document Requirements conform to AMSE Y14.5M-2009 I Y

3.4.3 Materials and Workmanship Requirements I Y

3.4.4 Stress Relieving Requirements I Y

3.4.5 Surface Finish, Coatings and Paint Requirements surface finish of 64-microinches or better I Y

3.4.6 Grounding I Y




3.4.7 Labeling Drawing 164350 I Y

3.4.8 Metrology, Inspections, and Factory Test Requirements

calibrated and traceable to established standards I Y

3.4.9 Reliability and Lifetime Requirements Lifetime of 40 years A A A Y

3.5.1.1 M2 Transport Container To and from coating vendor per 3.3.2 and 3.3.3 A,I Y

3.5.2.1 M2 Transfer Interface Plate ICD TBD I Y ICD TBD

3.5.2.2 Protective Cover Brashear A,I Brashear


Risk Assessment

Technical

– Fabrication of substrate-Low Risk

• Similar sized SiC have been fabricated (ABI scan mirrors)

• Internal R&D has demonstrated techniques and processes for 650 mm substrate

• Established machining vendor base

– Bonding of Bipods-Low Risk

• Process has been demonstrated for multiple SiC programs

– Silicon Cladding-Low Risk

• Vendor base established and demonstrated on multiple SiC programs

• Detailed process in place for tooling, surface preparation, deposition of silicon and

inspection

• Risk similar to complex optical coating risk

– Grind and Polish of optical surface-Low Risk

• Tinsley has significant heritage with silicon clad, SiC aspheres

– Reflective Coating-Low Risk

• FSS99 baseline coating has heritage to multiple flight programs

Schedule

– Long Lead items for substrate fabrication-suggest placing tooling orders as soon as possible


teoa m2 optical assembly fabrication - dkist · 2020-01-22 · l-3 communications proprietary jay...

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