Testing for COTS components

According to European Cooperation for Space Standarization (ECSS), COTS components is a commercial electronic part readily available off-the-shelf, and not manufactured, inspected or tested in accordance with military or space standards

The drive to use COTS (Commercial Off-The-Shelf) components in the space industry is growing since these parts allow to obtain higher performance at the system level, which is difficult to obtain using currently available space components. However, the use of COTS components has an inherent risk because of the lack of confidence in the traceability and the long-term performance of these parts as well as the new concerns affecting mostly this type of products (RoHS, counterfeit parts, long-term reliability, etc.).

Consequently, COTS parts should be considered only if existing hi-rel alternatives are impractical from a performance point of view.

Advantages of using COTS in space application

A key factor for the safe use of COTS parts in space application is to take into account the specific quality and reliability concerns associated with the use of these components in space applications, as well as to obtain technological knowledge and manufacturers’ support necessary to properly estimate the risk and the required countermeasures.

With the introduction of a stringent methodology for product assessment, selection, procurement and testing (screening and qualification), using COTS components can provide a solution when space level parts are not feasible or available for the intended application.

Methodology for the selection and procurement

• Risk assessment. Functionality, Support, Production.
• Part selection. Obsolescence control, Know how, Experience.
• Reliability assurance. Characterization, Screening, Validation.

Qualifying COTS at a reduced cost

When qualifying COTS components, we are fully characterizing the device under space environment working conditions. These COTS are not guaranteed for Space use by the Manufacturer. ALTER guarantees that the parts are tested strictly in accordance with agreed conditions. Then, strictly speaking, when a result deviates from the expected behaviour (under normal environmental conditions) ALTER will raise an incidence report that will be treated together with you to assess the acceptability for your specific project. Although the test execution can be interrupted once the failures are found, providing some saving of the overall cost, take into account that most of the Non-Recurrent Cost will be incurred before the test starts so they will be invoiced. ATN will work with all participants in the project to define the next steps after failure, including assessment about other parts providing more confidence.

COTS components testing

ALTER offers a global solution to specific concerns about the use of COTS space components, such as life cycle (obsolescence) or counterfeit detection, integrating all required steps into the supply and testing chain and providing alternative solutions and risk-mitigation strategies. The company has an accumulated experience on validation of any kind of EEE component putting in place a stringent methodology for product assessment, selection, procurement and testing (evaluation, screening and qualification).

Based on the accumulated experience, and in close cooperation with the customer, specific test flows can be defined for each individual type of components.

The risks associated with the use of COTS can be minimized by means of:

• Appropriate product selection
• Evaluating device construction
• Radiation evaluation
• Incoming inspections
• Defining proper test flow
• Performance of reliability tests

Reference documents: 

• PEM-INST-001, Instructions for PEM Selection, Screening and Qualification (NASA)
• EEE-INST-002, Instructions for EEE Parts Selection, Screening, Qualification and Derating (NASA)
• ECSS-Q-ST-60-13, Commercial Electrica, Electronic and Electromechanical components (ESCC)
• ATN-TN-001, Management of COTS for Space Applications (Alter Technology)