The National Aeronautics and Space Administration (NASA) invites potential offerors to submit a response to this RFI to find interested and qualified sources for the design, development, and collaboration for the fabrication of two flight-like engineering development unit (EDU) Coriolis flow meters to accurately measure any typical satellite propellant fluid or gas within a temperature range of 0 to 50 deg C (non-cryogenic).  Some fluids include, but are not limited to, liquid hydrazine (N2H4), liquid nitrogen tetroxide (N2O4 or NTO), liquid monomethylhydrazine (MMH), liquid water, and liquid anhydrous ammonia.  The capability of the same or similar device (extensible with minor design / manufacturing modifications) to measure pneumatic or supercritical gas would also be of benefit.  Such gases would include helium, nitrogen, and xenon all at a higher maximum expected operating pressure (MEOP) of up to 6000 psig compared to the MEOP listed in the included table.

The eventual goal of a future flight derivative of such a meter is to accurately measure a fluid being transferred from one spacecraft to another in geosynchronous orbit (GEO) and eventually between cis-lunar, deep space, lunar or Martian surface vehicles.  

NASA is soliciting responses to determine the applicable rough order of magnitude (ROM) cost and schedule for the design and development of two flight-like EDU Coriolis flow meters that may be used for environmental and functional testing at NASA facilities.  The test articles will be designed by the vendor, built at the vendor and third party facilities, and acceptance tested at NASA facilities to ensure that the design meets the stringent requirements of the deep space environment, such as radiation, vacuum, and electromagnetic interference (EMI) for the electronics.  The fabrication includes typical workmanship standards such as the American Welding Society (AWS) and Electrical and Electronic Engineering (EEE) or approved equivalents for the EDUs.  Refer to Section 4 of the RFI reference document “Coriolis Flow Meter Performance Goals and Environmental Requirements”.  The wetted components of the flight-like EDUs shall be certified to the requirements of AIAA S-080 or a similar aerospace code approved by NASA.  The response should include the cost and schedule estimate for the production of 2 units to the requirements listed herein.  Note the actual fabrication and acceptance testing of the electrical hardware (circuit boards) and space-flight rated electrical component procurements do not need to be included in the quote.  If requested by manufacturer, this scope could be performed as government furnished service in collaboration with the vendor, NASA, and a third party.  The wetted and mechanical components will be fabricated by the vendor.

The intent of this RFI is to obtain information from industry to assist NASA in its acquisition development.  NASA is soliciting for interest from all companies with past experience and qualifications in this type of design, fabrication, and qualification/test service.  This includes past aerospace heritage companies and other companies interested in expanding their production line to aerospace qualified components via collaboration with an experienced government engineering, manufacturing, and quality assurance team.

NASA reserves the right to share all information received in response to this RFI throughout various NASA centers / programs and to use all information submitted in response to this RFI in NASA’s formulation of a potential later formal solicitation seeking competitive proposals.  However, any submitted competition sensitive data should be clearly marked proprietary and will only be shared with the NASA specific solicitation team civil servant members.  Although information contained herein represents current program content and acquisition planning, it is subject to change.  Response to this RFI is requested within the context of the general approach described in the following paragraphs and attached document.

The Government will provide in its planned future Request for Proposal a more detailed performance specification which outlines the flight qualification levels required for any technologies proposed; however, the additional reference document titled “Coriolis Flow Meter Performance Goals and Environmental Requirements” can be used as an initial guide for this RFI.

Coriolis Flow Meter Overall Description and Preliminary Requirements

The characteristics listed in Table 1 are the key goals required to support planned operations.  Reference the additional document posted with the RFI titled “Coriolis Flow Meter Performance Goals and Environmental Requirements” for further information on the design parameters.

Table 1

Flow Meter Performance – NASA Key Goals

Fluid Compatibility

Required: N2H4, deionized water, and isopropyl alcohol

Desired: MMH, N2O4, CFC-113, NaOH

Min/Max Flow Rate

0.001 to 0.1 kg/s

Fluid Temperature

0 to 50 degrees C

External Temperature Exposure

(Non-Operating Temperature while Dry)

-70 to 60 degrees C

Pressure Operating Range (MEOP)

0 to 500 psig

Proof Pressure

1.5 X MEOP (hydrostatic test)

Burst Pressure

2.5 X MEOP for AIAA or approved equivalent

Totalized Mass Accuracy (Forward)

0.5% or better for 100 kg transfer at >0.02 kg/s

Totalized Mass Accuracy (Reverse)

0.5% or better for 200 kg transfer at >0.02 kg/s


0.2% or better

Turndown Ratio

20:1 or better at <0.5% totalized accuracy

Liquid Throughput Capacity

Up to 20,000 kg

External Leakage

1 X 10^-6 standard cubic centimeter per second (SCCS) with gaseous helium (GHe)

Mechanical Fluid Line End Interface

Female boss per SAE AS5202, tube fitting per SAE J514,

or Swagelok VCO® for ground test unit


RS-485 is preferred

(would accept others except analog voltage/current)

Electrical Interface

RS-485 preferred if signal is digital

(if not, recommend alternate)

Power Supply Operating Voltage Range

+28VDC nominal (+24VDC to +32VDC)

Power Draw

Not to exceed 50 W at any time

Storage Life

10 years

Operational Life

10 years (usage >2 times per year for up to 24 hours each)

Additional Summary of Proposed Component Capabilities

NASA is soliciting for the approximate values/ranges of industry past flight or ground experience/qualification levels for key historical discriminators of the following parameters to leverage evolved development resulting in production time and development cost savings.

  1. Mass flow rate range and unit pressure drop at 0.1 kg/s
  2. Device size and mass (including required electronics)
  3. Cycle and usage life
  4. Fundamental frequency (electronics and measurement device)
  5. Mean time between failures
  6. Required power, current draw, in-rush start up current, and ground resistance
  7. Minimum, maximum, and preferred sample rate
  8. Recommended calibration cycle (based on accuracy degradation over time, if any)
  9. Electrical interface (typical options offered, such as RS-485)

The vendor shall provide information for the following parameters and discuss how the design performance (accuracy) will be impacted by their variations: 

  1. Temperature, pressure, density, and viscosity
  2. Vibration and shock during non-operational launch phase
    1. Externally induced limitations
  3. Radiation exposure limits over usage life
  4. Magnetic fields
  5. EMI/EMC
  6. Percent two-phase flow

The vendor shall also provide information and/or recommendations related to the following: 

  1. Signal conditioning
  2. Required supporting hardware (for nominal operation)
  3. Ability to maintain listed requirements following flow path exposure to vacuum and rewetting at high flow rate including water hammer effect (at near instantaneous pressure surges up to 1.2x MEOP)
  4. Ability to differentiate gas from liquid states
  5. Ability to withstand the external pressure decay of a launch (sea level atmospheric pressure to vacuum at ascent pressure loss rate of approximately 0.8 psi/sec)
  6. Mechanical mounting interface (vibration isolation requirements or nonoperational vibration limits without impact to later operational use, etc.)
  7. Internally created vibration range
  8. Compatibility with high frequency pulsed flow (>50 Hz)
  9. Required flow conditioning and measurement linearity
  10. Potential outgassing of materials
  11. Required electronics, circuit boards, etc. that manufacturer would need assistance with upgrade to flight qualification standards (if must be local to sensor unit vs. use of satellite processor for compiling or computing output results of sensor)
  12. Required software and if manufacturer under potential flight contract would be willing to share detailed root code with government engineers or can unit’s raw output signals be processed using standard methods

The vendor shall also provide information related to the response (any past qualification or test / analysis levels) of the unit to

  1. Radiation
  2. Vibration (random and sinusoidal) and quasi-static acceleration
  3. Shock during and prior to use (e.g. during launch while the unit is unpowered)
  4. Thermal vacuum
  5. EMI/EMC

Note that any items not tested or analyzed should be marked as not tested or analyzed previously to help assist with NASA delta qualification time requirements and cost assessment.

Specific Information Solicited for this Request for Information: 

Responders to this RFI are encouraged to comment on any of the preliminary requirements listed and/or to express their interest in this proposed acquisition by submitting the following information:

  1. Organization name, address, principal activity, business size, and primary point of contact
  2. Rough estimate of cost and schedule for each of the following:
    1. Design and development, including documentation for NASA formal design review/approval of all drawings, analysis, bill of materials, and test plans for two flight-like EDUs.  Note the actual fabrication and acceptance testing of the electrical hardware (circuit boards) and space-flight rated electrical component procurements do not need to be included in the quote.  If requested by manufacturer, this scope could be performed as government furnished service in collaboration with the vendor, NASA, and a third party.  The wetted and mechanical components will be fabricated by the vendor.
    2. Please note in estimate, if vendor would be potentially offering up any of its investment capital to new research and technology product lines that could have potential future multiple user / program use or would require 100% government funding of development efforts.
    3. Note that the use of an existing Coriolis sensor design is acceptable if paired with flight rated electronics developed under this effort as long as the sensor design shows reasonable margins for the requirements listed in the table and attached document.
  3. Lead times for design and development for delivery of design to NASA and third party fabrication vendor.
  4. Description of your company’s experience in developing and producing devices of a similar nature for aerospace systems or other stringent Department of Defense or nuclear industry applications or uses, similar to the requirements described in this RFI
  5. Documentation demonstrating your company’s core competencies (skills, knowledge, expertise, facilities, production equipment, quality certifications, and documentation systems)
  6. Typical vendor device characteristics from previous flight or ground qualified units of a similar design for all items shown in this RFI or submit outline of plan for delta design/qualification of component, if not previously aerospace flight qualified

Response Instructions

The requested responses are for information and planning purposes only. NASA does not intend to post information or questions received to any website or public access location. NASA does not plan to reply to the individual responses, and respondents will not be notified of the results of the evaluation. Respondents deemed fully qualified will be considered in any resultant solicitation for the requirement. Feedback to this RFI may be utilized in formulating the Government’s acquisition strategy and documents. All responses should be provided electronically in Microsoft Word document format. Font should be Times New Roman, size 12. Responses should not exceed 15 pages and should reference RFI# NNK22ZES002L. Please submit electronic responses no later than 4:00 PM ET, on Tuesday, January 4, 2022, to the NASA/KSC Procurement Office, e-mail

This preliminary information is being made available for planning purposes only, subject to FAR Clause 52.215-3, entitled “Solicitation for Information and Planning Purposes”. It does not constitute a Request for Proposal, Invitation for Bid, or Request for Quotation, and it is not to be construed as a commitment by the Government to enter into a contract. Moreover, the Government will not pay for the information submitted in response to this RFI, nor will the Government reimburse an Offeror for costs incurred to prepare responses to this RFI.

No solicitation exists at this time; therefore, do not request a copy of the solicitation. If a solicitation is released later this fiscal year as currently planned, it will be synopsized in the and on the NASA Acquisition Internet Services (NAIS). It is the potential Offeror’s responsibility to monitor these sites for the release of any solicitation or synopsis.

Please advise if the end desired flight-like EDUs requirement is considered to be a commercial or commercial-type product. A commercial item is defined in FAR 2.101.

NASA Clause 1852.215-84, Ombudsman, is applicable. The Center Ombudsman for this acquisition can be found at .

POINT OF CONTACT:  Timothy Freeland, Contracting Officer NASA/KSC Procurement Office Phone:  321-867-1095  Email:

SECONDARY POINT OF CONTACT:  Brian Nufer, Engineer, Fluid Systems NASA/KSC Phone:  321-861-7311  Email: