Industry_Questions_and_Answers.pdf

ANSWERS TO INDUSTRY QUESTIONS

Solicitation # 80GRC018R0027

Posted 8/15/18

High Capacity 90 Kelvin Cryocooler for Thermal Control of Space-Based Cryogenic Systems

STUDY

Question 1: Figure 4 in Paragraph 3.1 mentioned that cryocooler will consist of more than one module.

Is there a maximum number of modules that NASA can accommodate?

Answer: No.

Question 2: Can NASA define the length and ID of the convection loop so that we can calculate the parasitic heat leak and the pressure drop in the flow line?

Answer: The pressure drop is given “as less than X” in the SOW. Those parameters will depend on application to a certain extent. Precise details can be worked out during the initial development. For now, start with ~ 20 feet of 1” line and 8 parallel runs of ~ 8 feet each.

Question 3: What is the maximum allowed static pressure of the neon convection fluid, both at load temperatures of 300K and 90 K? What is the volume of the convection loop?

Answer: There is no set maximum pressure; the test hardware (again depending on test) can be modified to meet most reasonable pressures. For volume, see the comment above – precise details can be worked out during the initial contract.

Question 4: The integrated cryocooler system cooling capacity is 135W +/- 12% not including any parasitic loss due to integration. The parasitic loss is a function of the length of the convection loop. Can NASA define the length of the convection loop so that we can calculate the parasitic loss, or alternately define the parasitic loss?

Answer: See answers above. Alternatively at the preliminary state, assume a percentage of the total lift.

Question 5: Is there a limit on the heater load used to raise the environmental temperature from 200K to a higher temperature?

Answer: Not at the moment.

Question 6: The integrated cryocooler system specific power shall be 15 W/W. Will NASA give special consideration if we propose testing a prototype cooler to demonstrate the cooler efficiency?

Answer: Eventually, NASA wants to develop and test a prototype cooler. If NASA GRC feels that is appropriate and fits within the cost window, then NASA will consider that.

Question 7: The following are related to the proprietary natures of the material specified in the RFP.

Can we meet the requirements by releasing summary data without releasing proprietary data?

• The contractor shall provide an analytical model outlining the cryocooler predicted performance.

• The contractor shall provide software specifications including the architecture and overall system specifications.

• Paragraph 4.4: Final written report: CAD model of the integrated cooler system conceptual/preliminary design shall be delivered to NASA as STEP files.

Answer: Yes.

ANSWERS TO INDUSTRY QUESTIONS

Solicitation # 80GRC018R0027

Posted 8/15/18

Question 8: Do you know the estimated number of cryocooler systems that NASA anticipates it will procure in the future?

Answer: No.

Question 9: What is the estimated timeframe is for procuring the cryocooler systems?

Answer: Timeframe for first flight is ~ FY 2026, targeting an engineering prototype in the FY 21/22 timeframe.

Question 10: Would NASA be interested in a response from a potential offeree with considerable terrestrial, including Milspec cryocooler experience, and some legacy to previous “Space” Stirling engine flight development/qualification (not completed) efforts/programs but only limited/indirect legacy to “space” cryocoolers?

Answer: Yes, NASA is hopeful that this solicitation will encourage new sources for space-rated cryocoolers.

Question 11: Does NASA have any interest in, and would it be considered responsive to this solicitation, to propose a dual temperature cryocooler capable of providing both the 90K heat lift that is the focus of this solicitation, and the 20K heat lift also described in, but not the focus of, this solicitation?

Answer: No, NASA wants 90K only.