TAB_2_SOW_8-10-17.pdf

Statement of Work Langley Research Center (LaRC) Experimental Test Range (ETR) Absorber Replacement

August 11, 2017 Purpose - This requirements document identifies specifications to install and replace the ETR Radio Frequency (RF) absorber. The integrity of the existing RF absorber material was compromised by exposure to humidity during a facility upgrade. The absorber has taken in moisture which increased its mass and weight, causing the tips to sag and reducing the electromagnetic (EM) performance of the material. The EM absorber material requires replacement to achieve the desired chamber performance to meet existing and future program/customer technical, operational and mission scheduled objectives.

There is also a safety issue due to the risk of the absorber panels falling from the ceiling as a result of taking moisture due to humidity. This installation does not require a Chebyshev design.

Background -The ETR compact range anechoic chamber, built in the 1990’s, is used to create a far field EM environment to enable researchers to quantify antenna gain patterns and radar cross section signatures from 300 MHz to 40 GHz. In order to meet the LaRC Vibrant Transformation to Advance Langley (ViTAL) plan objectives to have the ETR include the capabilities of the other anechoic chambers housed in building 1299, this branch has continued to utilize internal branch funding and cost sharing opportunities, and is presently undergoing major investments to enable it to be fully operational by 2020 to replace the capabilities currently housed in the LaRC compact range pilot facility and tapered antenna chamber. These facilities will be removed from service in 2020 in accordance with the LaRC ViTAL plan. A photograph of the ETR reflector and chamber walls is shown in Figure 1 (see Attachment A).

Facility Description - The ETR chamber volume is 40’ by 40’ by 100’. The ceiling, walls and floor are covered with EM absorber designed to maximize field performance between 300 MHz and 18 GHz. The main access to the chamber is through the back wall which contains a 30’ high x 16’ wide opening consisting of four panels that hang in tracts that form a solid wall when closed. The doors are manufactured by HUFCOR Inc from Janesville, WI (order No. 512693-1M). The feed antenna is located to the side of a parabolic reflector with rolled edges that is approximately 27.5’ x 27.5’ (8.4 m x 8.4 m). The doors have a warning label that water based adhesive should not be applied for face material application. The facility has a floor rail system to traverse test targets into the chamber. Figure 2 (see Attachment A) shows the rail system. Figure 3 (see Attachment A) shows the reflector support substructure.

Certifications – The vendor shall provide test documentation certifying each individual piece of absorber delivered meets the tolerance specifications for dimensionality, humidity absorption, UL-94HBF fire retardant and RF reflectivity.

Specifications:

Base/Option

Base/Option Approximate

Start Date

Approximate Delivery

Date (NLT) Area Coverage Material Zone Installation Disposal

Base September

November

2017 600 sqft Partial floor 6' x 36" Wedge IV No No

1 August 2018

December 2017 Back chamber wall w/doors 40' x 40'

36” Curvilinear Pyramid V Yes Yes

2 August 2018

September

Two side walls 40' x 100' 44’ Pyramid, 56’ Wedge

36" Wedge & Pyramid *

II, III &

IV Yes Yes

3 August 2019

December

2018 Remaining floor 36" Wedge & Pyramid **

II, III, &

IV Yes N/A

4 August 2019 September

2019 Ceiling 40' x 100' 36" Wedge & Pyramid

II, III, &

IV Yes Yes

5 August 2019 December

2019 Front wall 40’ x 40’ 12" Pyramid I Yes Yes Table 1 Deliverables

The contractor shall provide polyurethane EM absorber for the ETR facility in accordance with the following phases:

• The implemented design shall use industry best practices in the RF absorber chamber installation to minimize discontinuities anywhere in the anechoic enclosure.

• The EM absorber must be certified to comply with UL-94HBF fire retardant requirements.

• Fabrication Tolerances to be met thru individual testing:

o 90 degree cuts shall be no more than 90 degrees +/- 0.4 degrees o Piece to piece dimension variation shall be no more than:

+/- 0.125 inches in length, width and height.

• Dimensional stability with changes in humidity (< 10% - 80%) o Material dimensions (length, width, height and tip location) shall be stable to within +

0.0 inches / - 0.125 inches, over the humidity range specified

• 6 foot length wedge absorber shall be used where appropriate to minimize joints between the absorber.

• The maximum reflectivity of the 36” pyramid shall be:

o -30dB @ 300MHz o -45dB @ 1GHz o -50dB @ 10GHz

• Absorber chamber installation shall require materials being glued to the ceiling and walls with manufacturer recommended adhesive.

• The absorber shall maintain electrical performance and structural integrity within the ETR environment:

o Temperature: 55 – 90 degrees F o Relative Humidity: 20 – 80%

Base

• Dimensional depth to be approximately 36” for zones II thru V.

Option 1

• Dimensional depth to be approximately 36” for zones II thru V.

• The chamber back wall identified as zone V shall be installed with a curvilinear pyramid absorber to minimize the back scatter reflection.

Option 2

• Dimensional depth to be approximately 36” for zones II thru V.

o *Requires absorber to cover substructure and rails

Option 3

• Dimensional depth to be approximately 36” for zones II thru V.

o ** Pyramid shall extend 44’ from front wall

• Absorber covering the rails shall be installed over a low profile platform that must be manually removed and replaced for accessing target transportation rails. This 36” wedge absorber can have a durability coatings to minimize absorber damage from regular handling. The rail cover absorber will be handled regularly.

o The Contractor shall install integrated EM absorber to the substructure beneath the reflector and target transport rails to minimize backscatter reflection. A diagram of the ETR facility is shown in Figure 4 (see Attachment A).

Option 4

• Dimensional depth to be approximately 36” for zones II thru V.

Option 5

• Dimensional depth to be approximately 12” for zones I.

Safety and Health Plan Requirements: The Contractor shall submit a Safety and Health Plan within 15 calendar days of award date. The Contractor shall not commence work until a functional review of the submitted Safety and Health Plan is completed by the NASA LaRC Safety and Mission Assurance Office (SMAO) Safety and Facility Assurance Branch (SFAB) and the Safety and Health Plan is approved by the Contracting Officer. The contractor shall attended an onsite safety briefing starting at 7:30 before initial work commences. The Contractor is required to continually update the Safety and Health Plan when necessary (e.g., requirement change, safety regulation change, safety incident impact). The Contractor shall submit a revised Plan for Contracting Officer approval no later than 30 calendar days after the effect of a change or incident. The Safety and Health Plan shall be written to address the following:

• The contractor must follow all NASA and Federal regulations.

• Designated Safety Official responsible for implementation and adherence to the proposed

Safety and Health Plan.

• Describe the procedures used to identify hazards associated with the work to be performed on the contract as well as the hazards associated with operations in close proximity to contract operations (i.e. Job hazard analysis, daily safety briefings, etc.)

• Describe methods for employees to report (reprisal-free) hazardous conditions (e.g., close calls).

• Describe the hazard communications program as defined in CFR 29 Part 1910.1200 and LPR

1710.12. Include process for compliance with and updating of Safety Data Sheets (SDS) for each chemical, glue, solvent, etc., used on the job-site.

• The contractor must present documentation showing the onsite contractor received all appropriate safety training for duties performed as required by OSHA (i.e. aerial lift, fork lift, fall arrest systems, etc.).

• Address process for immediate reporting of all serious accidents, injuries, and close calls to the NASA LaRC Safety Office at 864-7233. Submission of documented accident, injury and close call reports shall be provided to the NASA LaRC Safety Office within 24 hours of the accident, injury, or close call.

Figure 1. ETR reflector and chamber walls.

Figure 2. Rail system

Figure 3. Reflector showing support sub structure

Figure 4 Diagram of ETR facility.

Zone IV wedge

Zone III pyramidal pyramidal Zone I 0 1 2-1-2-3-4-5-6-7 3 4 5 6 7

-1

-2 -3

-4

-5 quiet zone

30.5 m (100 ft.)

reflector

D ow n-Range (m

Cross-Range (m) reference point (internal use only)

Zone II pyramidal pylon rails w alkw ay pyramidal Zone V feed