What is NASA EEE-INST-001 Standard?

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Dec 25, 2022

The NASA EEE-INST-001 provides instructions for choosing Capacitors, Crystal Oscillators, Diodes and Transistors, Fiber Optics, Filters, Fuses, Microcircuits, Magnetics, Relays, Resistors, Thermistors, Wire and Cable based on mission needs and requirements. 

To qualify for certain specific missions, the parts or equipment must be tested and approved by NASA under the NASA EEE-INST-001. Like all Devices used in space, the equipment must also meet the stringent testing for outgassing (the release of trapped air) and residual magnetism to be suitable for use in space applications. These guidelines are set by Nasa’s EEE-INST-001 guidelines for reliability.

The NASA EEE-INST-001 has laid out three reliability levels of equipment that can be used for several space explorations. The term  “Level” is attached to each component. A Level 1 Part has the highest performance & reliability while a Level 3 part has the lowest. 

  • A reliability Level 1 part has the highest manufacturing control and testing per military or DSCC specifications and low-risk parts for missions 5 years or longer. 
  • Level 2 part has reduced manufacturing control and testing for mission duration being 1-5 years. 
  • Level 3 Part has no guaranteed reliability controls in the manufacturing process and no standardized testing requirements for programs with a mission duration of less than 1 year and up to 2 years. The reliability of the level 3 part can vary significantly with each manufacturer, part type, and LDC due to unreported and frequent changes in design, construction, and materials and they are more likely to fail than the level 1 part.

EEE Parts are specified in the following table for each Federal Stock Class (FSC). The FSC is a code given to a specified part/equipment that allows for the grouping, classification, and naming of such equipment to be used for space applications.

Section

Part Type

FSC

A

Capacitors

5910

B

Connectors

5935

C

Crystal Oscillators

5955

D

Diodes and Transistors

5961

E

Fiber Optics

60GP

F

Filters

5915

G

Fuses

5920

H

Microcircuits, Hybrid

5962

I

Microcircuits, Monolithic

5962

J

Magnetics

5950

K

Relays

5945

L

Resistors

5905

M

Thermistors

5905

N

Wire and Cable

6145

 

EEE parts shall be Selected, Screened, and Qualified by the detailed requirements of a specific mission case for applicable part types and quality levels.

Selection: The EEE Parts can be selected based on reliability levels as well as their respective applications and performance.

  • Military Specification: Most preferred parts are used for military specifications or Standard Military Drawings (SMDs), many consisting of at least 2 reliability levels. Not all military specifications are acceptable for space applications. Unless specifically allowed By the NASA EEE INST 001 Document, it is the responsibility of the user or the engineer to ensure that the aforementioned equipment and other military specifications satisfy the requirements
  • Source Control Drawings (SCDs): This designation includes parts that are procured to a user-controlled specification or custom requirement such as an SCD. The SCD shall include the screening and qualification requirements. in addition to performance parameters, absolute maximum ratings, case outline, terminal description, and other unique requirements. The testing required by the SCD is to be performed by the manufacturer and does not have to be repeated by the user. If an acceptable government-controlled specification is not available for Level 1 programs, an SCD is required along with all the other mentioned testing parameters which shall yield successful results.
  • Manufacturer High Reliability: This part designation includes parts intended for high-reliability applications which are procured to a manufacturer-controlled test program as described in the manufacturer’s catalog. They are controlled only by the manufacturer, who assigns them a special part number and provides a certificate of compliance that they have been tested as advertised.
  • Commercial:   Commercial/consumer parts should be avoided in space applications. Some high-reliability commercial parts, such as Automotive Quality System (AQS) parts, may be acceptable for space applications. It is the responsibility of the user to understand and document the applicable specification or test plan requirements.

Screening:  Screening tests are intended to remove nonconforming parts, parts with random defects, or parts likely to experience infant mortality, from an otherwise acceptable lot and thus increase confidence in the reliability of the parts selected for use. Screening tests shall be performed on flight parts. These tests are in addition to tests performed by the manufacturer for each part designation. Screening tests shall be performed in the order shown unless otherwise indicated. The user or Engineer is responsible for specifying the device’s unique requirements if any.

Qualification: Qualification testing consists of mechanical, electrical, and environmental inspections and is intended to verify that materials, design, performance, and long-term reliability of the part are consistent with the specification and intended application, and to assure that manufacturing processes are controlled. Qualification by usage history or similarity to qualified parts may be acceptable as discussed below.

  • History: A part can be considered qualified if it has been successfully used in

(a) applications identical to that proposed (heritage design) or 

(b) applications different than that proposed, if the application, including derating and environmental conditions, is fully documented and is more severe than the proposed application. 

The part must have been used for 2 years minimum total operating time in orbit. The part must have been built by the same manufacturer in the same facility using the same materials and processes as an equivalent SCD. It is the responsibility of the user to have such evidence documented. 

  • Similarity: A part can be considered qualified if it is similar to a part for which qualification test data exists, and the test data –

(a) satisfies the requirements specified herein for the applicable part level, and 

(b) is available and is less than 2 years old relative to the lot date code of flight parts. To be considered similar, the part shall be made by the same manufacturer on the same manufacturing line or a line with only minor differences, and these differences shall be documented and shown to represent no increased reliability risk.

  • Existing Test Data: Parts can be qualified by existing test data that meets the requirements (a) Lot Specific Data indicates that flight parts have the same lot date code as the qualification samples. Lot-specific data is always acceptable in place of qualification testing when it meets the requirements specified herein.

 (b) Generic Data is an acceptable basis for qualification if it is less than one year old relative to the lot data code of flight parts, and is acquired and reviewed for acceptability by the user. The user shall also verify that the data is representative of flight parts: e.g., built in the same facility using identical or equivalent processes.

Audits & Customer Source Inspection (CSI)

  • Audits: Audits are not necessary for all parts & equipment. However, for Level 1 and Level 2 parts, a site visit to assess the manufacturer’s capability in satisfying the requirements specified herein is recommended for unproven manufacturers. The term “unproven” means that the user has not previously procured parts from the manufacturer, or that the manufacturer has not established a history of supplying reliable parts for space applications. The user is encouraged to consult the NASA Core Suppliers List (CSL) on the World Wide Web for technology, process, and audit information on approved suppliers, and audit/CSI requirements for “unproven” manufacturers.
  • Customer Source Inspection (CSI): CSI is not a requirement but is recommended for unproven parts intended for use in Level 1 and Level 2 applications, and parts of manufacturers with a known problem history. CSI is most effectively performed at precap visual inspection and the final electrical test. If CSI is used as a substitute for required data (i.e., data is reviewed at the manufacturer’s facility rather than acquired by the user), then the CSI shall be fully documented in a trip report. This should summarize the data and reference manufacturer test reports by number.