Amendment 1 - ATTACHMENT 2 - PWS.docx

12760423Q0197

AMENDMENT 1 – ATTACHMENT 2

AMENDED ON AUGUST 08, 2023

National Infrared Operations (NIROPS) USDA/Forest Service Performance Work Statement (PWS)

12760423Q0197

AMENDMENT 1 – ATTACHMENT 2

Front Surface Mirrors for RS-25 Scanner

AMENDED ON AUGUST 08, 2023

Revision 2

Table of Contents

1. Background For about 10 consecutive months of each year the US Forest operates two airborne wildland fire mapping systems and maintains a third system as a spare. At the heart of these systems is a Texas Instruments RS-25 Kennedy Optics infrared line scanner. The US Forest Service needs to replace the six aging front surface mirrors within the scanner(s). The US Forest Service has some of the original specifications from 1960. The original 1960 mirrors were made from General Electric type 301 clear fused quartz or alternatively Pyrex #7740 (precision anneal). It has been observed over time these mirrors chip and the mirror surfaces have degraded. The US Forest Service also has revised specifications from 2004 & 2008 mirror purchases which were made from aluminum. These old specifications (Appendix B) are included as notes here and captured on drawings for reference to provide insight as to how it was done in the past.

The RS-25 is housed within a scanner/camera well built into the cabin of aircraft. The bottom of the scanner/camera well has a sliding door to protect the mirrors during takeoff and landings. The scanner is outside of the pressure vessel of the aircraft, so it is subject to the environment outside the aircraft, but not in the direct airstream. The scanner is subject to condensation, rain, sleet, and the occasional small bits of black sticky stuff (suspected of originating from the landing gear mechanisms and or turboprop engines). The upward facing parabolic mirror is where we normally find bits of sticky tar like substance, all the mirrors mostly just accumulate dust, dirt, and smoke particles. After a season of operation, the mirrors will have accumulated a fair amount of dust and small bits of foreign debris.

The RS-25 scanner and mirrors are subject to thermal cycling from tarmac temperatures of 60C (120F) to in flight altitude temperatures of -40C. This thermal cycling causes condensation and or fogging/frosting of the mirrors for each daily flight(s). When landing the entire scan head will be wet with water, and the water may run or drip.

2. Description of Work or Scope Build two sets of six each front surface mirrors from aluminum base material with a Protected Gold mirror surface to be used within the .865um to 12um spectrum. The operating temperature range of the finished mirrors is -40C through 60C. The base material of the triangular mirror shall be 7075 T6, all other mirrors will be 6061 T6, MIC-6, or ATP-5 stress relieved.

The new mirrors must be optimized for the existing 3-5um & 8-12um wavelengths and at the same time be functional at .865um and 2.2um wavelengths. The Forest Service will add two additional wavelength detectors to the RS-25 scanner, a .865um and a 2.2um.

The reflective surface shall be durable, have an environmental protective coating or otherwise be abrasion resistant for the airborne operating environment. Reflectivity and surface specifications are the same for each mirror surface and are listed by mirror name in appendix A.

The honeycomb pattern cut into the back of each mirror (excluding rotating triangular mirror) is for weight reduction while still maintaining stiffness and flatness. There are likely several materials and many weight reduction strategies that would be acceptable for this purpose so feel free to recommend alternative materials that cost less and are suitable for airborne operation, machining, and weight reduction methods, that reduce overall cost. Note: The Forest Service solid models leave .25 inch for mirror surface facing thickness. If an offeror believes .25 inch is not required, please state the minimum proposed thickness required to maintain mirror flatness and surface specifications throughout the operating temperature range.

The US Forest Service is open to alternate weight reduction designs in lieu of the modeled honeycomb, or strategies that will decrease mirror weight if they are structurally equivalent or more effective and cost less to make. The web thickness between the honeycomb cutouts may also be made narrower (if surface specifications can be maintained). The US Forest Service will defer to the vendor’s recommendation as to how much material can be removed and what cutout shape the vendor prefers. Acceptable deviations from the provided solid model will maintain similar weight reductions to the provided models and maintain mirror surface and flatness specifications throughout the operating temperature range. The vendor shall inform the Forest Service contracting officer and the technical representative of any proposed deviation(s) from the Forest Service solid models. Proposed changes to the modeled items are not approved unless formally accepted, noted and authorized by the contracting officer or contracting officer technical representative.

3. Tasks The provided solid models represent the finished mirror after plating, if the offeror has any concerns pertaining to tolerances, please verify with the Forest Service contracting officer technical representative, the Forest Service has made every effort to supply all critical dimensions, but an omission cannot be ruled out. The Forest Service has the solid models available in SolidWorks 2023 format, but we can provide STEP, IGES, and several other formats if needed.

3.1. The front surface mirrors will conform to or exceed MIL-PRF-13830B, 9 January 1997. Pay particular attention to Appendix B (Exclude the salt spray exposure, do not overlook the cellophane tape adhesion test requirement).

3.2. The front surface mirrors will be made of Protected Gold and have the following reflectivity figures.

3.2.1. >=95% @ .865um

3.2.2. >=97% @ 2.2um

3.2.3. >=97% @ 3-5um

3.2.4. >=97% @ 8-12um

3.3. Provide mirror handling and cleaning instructions, including acceptable cleaning agents, solvents, and their use of. (Consideration with respect to the tar like sticky substance occasionally found on the mirrors, dust, and smoke.)

3.4. Describe in detail any proposed deviations to the strategy for reducing the base material weight, and or overall weight of each mirror.

3.5. The following lists the names and quantity of parts that make-up one set of mirrors:

3.5.1. 2 each Top mirrors (the same design is used in two places). 6061 T6, or MIC-6, ATP-5 stress relieved.

3.5.2. each Side mirrors (the same design is used in two places). 6061 T6, or MIC-6, ATP-5 stress relieved.

3.5.3. 1 each Parabolic mirror. 6061 T6, or MIC-6, ATP-5 stress relieved.

3.5.4. 1 each Triangle mirror Alum 7075-T6.

3.6. The following two bushings are triangle mirror bearing journals, which are heat shrink or press fitted onto the mirror shaft, and precision ground for a hand interference fit of the bearings.

1. Bushing stainless steel (motor end)

2. Bushing stainless steel (Belleville washer end)

3.7. The hexagon lightening (weight reduction) pattern can have a small radius of .125” or less in the corners. The main goal is to lighten the mirror while retaining stiffness.

3.8. Please note, the center backside hole of the parabolic mirror is a circle and not a hexagon. This circle mates with a locating ball on the mirror carrier.

3.9. Rotating Triangle Mirror

Ideally the small approximately 1/2” space between each triangle mirror face along the length of the mirror will be antireflective black. If antireflective black is not possible then this 1/2” space will be abraded to break the glazed surface of any plating so this space can be hand painted Musou Acrylic flat black.

IMPORTANT

Please Note: ** A finite element analysis (FEA) of the triangular mirror was developed by an engineering team to validate structural integrity, projected lifespan, and airworthiness. The FEA engineers set a 4000 +/-50 rpm limit in the analysis. DO NOT EXCEED 4000 +/-50 rpm for any part of the manufacturing process. If 4000 +/-50 rpm is exceeded the part will have to be scrapped because the FEA is only valid for speeds of 4000 +/-50 rpm or less and torques <= 25 oz in. Applied torques in excess of 25 oz in to the final .75 inch diameter will decrease the service life of the part.

Torque applied to the final diameters of the end shafts:

Spin-up and spin-down are also important factors, the torque will ideally be <= 25 oz in when driving from the .75 inch motor end. A slow spin-up/down spanning 30 seconds should suffice when chucking the part. The .75 inch motor end shaft of the triangle mirror is the weakest area of the mirror. Care should be taken to minimize torque applied to the end shafts of the mirror during lathe turning. If possible, consider chucking and driving the triangle mirror material from both ends when lathe turning and take lighter cuts than would normally be used as the shaft diameter approaches the final .75 inch diameter. Increasing maximum rpm and torques applied to the final diameters of the end shafts is inversely proportional to the service life of the part.

Please Note: ** The rotating triangle mirror is to be burst tested at 4,000 RPM +/-50 RPM for 3 minutes at -40C and at 60C, then inspected using dye penetrant or other non-destructive evaluation.

4. Instructions to Contractors Please include the following information in your proposal.

4.1. Please identify any potential surface treatments as an option to reduce the frosting/condensation problem.

4.2. State the hardness, abrasion resistance, or Mil Spec of the final mirror coating.

4.3. Provide a graph or table of the reflectivity for the following frequencies: .865um, 2.2um, 3-5um, and 8-12um.

4.4. Provide a detail of the make-up of the offerors mirror surface and layers construction details.

4.5. ~~~~~~~~~~~State whether.25 inch can be reduced, is, or is not, acceptable for the mirrored faces base material thickness of the honeycombed parts.

4.6. Please provide cost for two sets of mirrors.

4.7. Please provide an estimated cost for one additional set as an option to purchase within the next 2 to 5 years.

4.8. If .002 oz in @ 4000 +/-50 rpm is not practical to attain, state the best balance specification you expect to achieve.

4.9. If any, please identify any requirements, specifications of concern, or recognized conflicts within this solicitation.

5. Government Furnished Information and Hardware

5.1. Upon request, The Forest Service can provide ABEC 7 hybrid ceramic ball bearings. The bearings MUST be returned to the Forest Service.

5.2. Solid models in SolidWorks 2023, STEP 2014, or IGES formats.

5.3. Finite Element Analysis of the triangular mirror for additional information.

5.4. Upon request, Two each Cylindrical Acrylic shipping containers for Triangular mirrors.

6. Acceptance Testing

6.1. The mirrors will be free of defects, conform to the solid models, and will meet the specified mirror surface specifications.

6.2. The mirrors will be installed in a RS-25 scanner and a cryocooled detector set will be positioned and aligned to the focal point.

6.3. The signal levels from the detectors will be measured and they will be equal to or greater in level than the signal level using the old mirror set being replaced. The origin of the signal will be a 500 degree Kelvin Black Body with a 1mil aperture.

6.4. The contractor will provide a certificate of conformance for the mirrored surfaces specification compliance.

7. Delivery

NIFC/NIICD/IR

Charles Kazimir 3833 S Development Ave Boise, ID 83705

8. Place of Performance The contractor shall perform services at its own or contracted facilities.

9. Period of Performance The period of performance for 2.0 through 2.1.I is 365 calendar days after award.

10. Payment Invoice will be submitted upon delivery and inspection and acceptance.

11. Forest Service Technical Representative The Technical Representative is responsible for the day-to-day technical communication with the Contractor relating to the work. In no event, however, will any understanding, agreements, modification, change order, or other matter deviating from the terms of this order be effective or binding upon the Forest Service unless formalized by proper contractual document executed by the Contracting Officer.

12. Technical Representatives:

Michael Mann or Charles Kazimir 208-387-5647, or Bill Forsyth 208-387-5720 Michael.Mann@usda.gov Charles.Kazimir@usda.gov Bill.Forsyth@usda.gov

13. Quality Control and Assurance (Commercial Services)

The Forest Service relies on the Contractor’s existing quality assurance system for commercial services as a substitute for Government inspection and testing before tender for acceptance unless customary market practices for the commercial service being acquired include in-process inspection. Any in-process inspection by the Government shall be conducted in a manner consistent with commercial practice. The Forest Service may conduct quality assurance for its benefit and has the right to refuse acceptance of nonconforming services. Quality issues with services tendered for acceptance or rejected by the Government shall be resolved under Contract Clause FAR 52.212-4(a), “Contract Terms and Conditions-Commercial Items”.

Performance Requirement Summary – The Performance Requirements Summary (PRS) table describes the acceptable quality level of performance expected by the Government and the means by which the Government may use to validate acceptable services.

13.1. Performance Requirements Summary Table

PWS

Para #

2.0 and 2.1

Build two sets of front surface mirrors for the specified infrared bands.

Tasks 2.0 through 2.1.I and in reference to Appendix A are completed as specified and delivered without damage.

The mirrors will conform to the solid models and mirror surface specifications.

Technical Representative(s) acceptance testing as outlined in Para 3.0

14. Rights in Data The mirror designs, specifications, and solid models are the intellectual property of the Government and shall remain the property of the Government as is or modified as necessary for this contract. The Service Provider is prohibited from using, publishing, or disseminating information resulting from work performed under this order and/or any other information provided by the Government, which the Contractor develops, for any purpose other than performance under this contract without prior written approval from the Contracting Officer.

15. Deliverables

1. Two Parabolic mirrors.

2. Four Side mirrors.

3. Four Top mirrors.

4. Two Triangular mirrors.

NIICD/IR Charles Kazimir 3833 S Development Ave Boise, ID 83705

Phone 208-387-5647 Due within 12 months of contract award.

16. Attachments Appendix A.

Notes from 1960 blueprint drawings are included in the following items descriptions/specifications. These notes are in reference to when the system only had 3-5um and 8-12um detectors in 1960, so if any of the following conflicts with this solicitations goal to make mirrors optimized to use .865um, 2.2um, 3-5um, and 8-12um bands please notify the Forest Service contracting officer and technical representative.

17. Parabolic Mirror comments:

Mechanical

01. Material 6061-T6. Alternate acceptable base materials are MIC-6, or ATP-5 stress relieved aluminum.

02. Nickle plating 0.003 in. / 0.0035 in. thick all over on mirror faces with a .05 inch wrap around edges. All non-mirrored surfaces will be plated with Iridite chem film per MIL-C-5541, Type II, Class 1A.

03. All dimensions after plating

04. All unfinished edges to have 0.01 inch chamfer

05. See cautions and guidance in 2.1.I Optical

01. Parabola Focal point at 6.500 in. +/- 0.050 from vertex.

02. All edges to have 0.01 in. chamfer, 4 each tips of parabola corners can be flattened to eliminate risk of bodily injury from sharp points.

03. Collimated light incident upon the full aperture of the paraboloid shall be focused by the paraboloid so that 90% of the incident light will be contained within a circle of confusion of diameter 0.002 in. and 100% within a circle of confusion of diameter 0.004 in.

04. Surface of parabola to be coated with protected gold high reflecting surface for 0.865um, 2.2um, and 2.5um to 15um wavelengths. The surface reflectivity will be optimized for wavelengths 3um to 12um and the reflectivity will be >=95% Ravg for .865um, and >= 97% Ravg for 2.2um, 3-5um, and 8-12um. (Original 1963 specification was “Surface of the parabola to be coated with high reflecting surface opaque aluminum film deposit coated with Silicon Monoxide, 0.5 wavelength blue-light.”) 04a. Uniformity of reflective coating +/- 1%, (approximately across entire mirror surface)

05. Center line of 0.5 in. diameter hole to be coincident with optical axis within 0.015 in.

06. Optical axis to be perpendicular to the side opposite the paraboloid to within 5 minutes

07. Center line of 0.5 in. diameter hole to be perpendicular to the side opposite the paraboloid to within 30 minutes

08. No orange peel visible to the unaided eye

09. No waviness or irregular surfaces, visible to the unaided eye

10. No greyness visible to the unaided eye

11. No beauty defects objectionable to the potential use except 10 pits not over .010 in. diameter and except 20 scratches not over 0.001 in. wide

12. All optical parameters are measured over the clear aperture on optical surface @ 6328 Angstroms unless otherwise specified.

13. Curvature uniformity: <= 1/2 wavelength per inch peak to valley

14. Irregularity: <= 1/2 wavelength per inch peak to valley

15. Surface Roughness: <= 50 Angstroms

16. Drilled hole tolerance +.005/-.001

18. Side Mirror comments:

Mechanical

01. Material 6061-T6. Alternate acceptable base materials are MIC-6, or ATP-5 stress relieved aluminum.

02. Nickle plating 0.003 in. / 0.0035 in. thick all over on mirror faces with a .05 inch wrap around edges. All non-mirrored surfaces will be plated with Iridite chem film per MIL-C-5541, Type II, Class 1A.

03. All dimensions after plating

04. All edges to have 0.01 inch chamfer Optical (All optical parameters are measured over the clear aperture on optical surface @ 6328 angstroms unless otherwise specified.)

05. Facet flatness: <= 1/2 wavelength per inch peak to valley.

06. Irregularity: <= 1/2 wavelength per inch peak to valley.

07. Optical quality: Scratch and dig, 40/20 per inch.

08. Surface roughness: <= 50 angstroms

09. Reflectivity: >= 95% Ravg @ .865 microns, and >= 97% Ravg @ 2.2um, 3-5um, and 8-12um.

10. Uniformity of reflective coating: +/- 1% (approximately across entire mirror surface)

19. Top Mirror comments:

Mechanical

01. Material 6061-T6. Alternate acceptable base materials are MIC-6, or ATP-5 stress relieved aluminum.

02. Nickle plating 0.003 in. / 0.0035 in. thick all over on mirror faces with a .05 inch wrap around edges. All non-mirrored surfaces will be plated with Iridite chem film per MIL-C-5541, Type II, Class 1A.

03. All dimensions after plating

04. All edges to have 0.01 inch chamfer Optical (All optical parameters are measured over the clear aperture on optical surface @ 6328 angstroms unless otherwise specified.)

04. Facet flatness: <= 1/2 wavelength per inch peak to valley.

05. Irregularity: <= 1/2 wavelength per inch peak to valley.

06. Optical quality: Scratch and dig, 40/20 per inch.

07. Surface roughness: <= 50 angstroms

08. Reflectivity: >= 95% Ravg @ .865um, and >= 97% Ravg @ 2.2um, 3-5u, and 8-12um.

09. Uniformity: +/- 1% (approximately across entire mirror surface)

20. Rotating Triangle Mirror:

Mechanical

01. Material 7075-T6, Note: Bearing journals are Stainless Steel, heat shrink, or press fitted, and then precision ground.

02. Nickle plating 0.005 in. / 0.0065 in. thick on mirror faces with a .05 inch wrap around edges. ~1/2 inch space between mirror faces will be painted low reflectance flat black. All non-mirrored surfaces will be plated with Iridite chem film per MIL-C-5541, Type II, Class 1A.

03. All dimensions after plating

04. Establish Datums on each end at bearing journals. All mechanical facet features checked from bearing journals. Facet to Datum tolerance of triangle mirror flats to be parallel to central axis within +/- 15sec total within a single polygon, maximum of 15sec to adjacent facets.

05. Facet to facet angle 120Deg +/-10sec.

06. Facet to center distance 1.215 inch +/- .0025 inch, variance within a single polygon +/- .001 inch.

07. All non-mirrored surfaces to have a 32 microinch finish or better.

08. The new mirror shall be balanced to within .002 oz in at 4000 +/-50 rpm.

09. 3/8-16 UNC, Deep threaded insert (9/16 inch deep threads minimum).

Optical (All optical parameters are measured over the clear aperture on optical surface @ 6328 angstroms unless otherwise specified.)

01. Facet flatness: <= 1/2 wavelength per inch peak to valley.

02. Irregularity: <= 1/2 wavelength per inch peak to valley.

03. Optical quality: Scratch and dig, 40/20 per inch.

04. Surface roughness: <= 50 angstroms

05. Reflectivity: >= 95% Ravg @ .865um, and >= 97% Ravg @ 2.2um, 3-5um, and 8-12um.

06. Uniformity: +/- 1% (approximately across entire mirror surface)

07. 3 each ~ ½ inch spaces between the mirror flats will be low reflectance flat black.

21. Appendix B Original build notes, FOR REFERENCE ONLY.

Rotating Triangular Mirror Special notes on 1963 blueprint Sequence of Operations:

Unless Otherwise Specified, General Tolerances;

Drilled Hole Tolerances:

Drawing Notes:

Note: The end of triangle mirror ends may be used for metal removal during dynamic balancing. Maximum depth of lightening holes not to exceed .30”(typical 3 corners each end as marked by hatch area.)

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