EMC for Space Systems – AIAA S-121A-2017

EMC for space systems

AIAA S-121A-2017 is a test standard based on military standards MIL-STD-461 and MIL-STD-464 that addresses EMC for space system requirements.  This standard relies heavily upon appropriate tailoring in the development of a test plan.

EMC and Space System Applications

The burgeoning New Space Economy is providing opportunities for a wide array of product developers to provide equipment and subsystems designed for space missions.  These systems must be robustly designed to be suitable for missions where high-reliability is essential.  The American Institute of Aeronautics and Astronautics (AIAA) has created this standard to provide designers with an adequate tool to conduct verification and validation testing for electromagnetic emissions and susceptibility. 

AIAA S-121A Testing

An emphasis in this standard’s test protocols is the testing of actual flight hardware in representative modes of operation.  This means that special attention must be focused on defining these methods and creating the necessary off chamber interfacing hardware to control and monitor the Equipment Under Test (EUT).  Furthermore, test planning should include the identification and documentation of risks and intended mitigations that will serve as a baseline for stakeholders’ decisions and rationale.

Test Requirements for Units and Subsystems

Requirements are normally tailored by the procuring agency to reflect the needs of a specific program.  These requirements include the following parameters

  • Conducted Interference for audio frequencies
  • Conducted interference for radio frequencies (50 kHz to 20 MHz)
  • Common mode emissions from power and signal cables
  • Antenna conducted emissions
  • Transient conducted emissions
  • Conducted susceptibility for power leads, antenna ports
  • Conducted susceptibility for bulk cables
  • Radiated Emissions for audio, magnetic, and radio frequencies
  • Radiated Susceptibility for magnetic and radio frequencies
  • Conducted Susceptibility for lightning transients 
  • Conducted Susceptibility from Personnel Bourne Electrostatic Discharge (ESD)

Special Test Requirements for AIAA S-121A

Test requirements and procedures for space applications can often exceed those of the military standards that this standard was derived from.  This can often be the case for radiated emissions where the limits for certain frequency bands are extremely low.  To achieve these measurements, tailored testing involving scans at reduced Resolution Bandwidths (RBW).  Performing these tests requires detailed communications with test facilities to ensure that testing is performable and to calculate required time for test performance.

CVG Strategy Experts

Our experts at CVG Strategy have extensive experience in EMI/EMC testing for a number of industries and products, both military and commercial.  We also have expertise in testing for space requirements including AIAA S-121A.  Our industry experts can assist in developing tailored test plans, test witnessing and troubleshooting.  We can also provide design analysis and guidance for space applications.

CVG Strategy is a consultancy offering coaching, mentoring, training and program development focused on areas including Business Process Improvement, ITAR and Export Compliance, Cyber Security and Quality Management Systems.

Jamie Hamilton

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