Space Missions and Risk Mitigation: Why electromagnetic compatibility testing is critical to their success


Authored by: Nika Amralah, Engineering Support

When it comes to space missions, one thing is paramount: risk mitigation. Extensive measures are taken in space projects to reduce the possibility of failure and to verify a spacecraft’s ability to perform its function once launched into space and in orbit. The importance of non-destructive spacecraft evaluation is to simulate and design for the effects of the launch and space environment on the materials, structures, and systems, to ultimately avoid material degradation, reduced functional lifetime, and mission failure. Specifically, electromagnetic compatibility (EMC) testing is an essential stage in spacecraft projects for mitigating risk.

Environmental testing is critical in the development of any spacecraft as it can reveal issues from poor quality control, assembly errors, damage, modelling and calculation errors, and more. The goal of testing is to iterate between identifying errors and subsequently addressing issues until all tests are passed. Once environmental testing is successfully complete, no changes to the spacecraft are permitted prior to launch. The sooner that spacecraft defects are identified, the less project delays, unnecessary costs and redesign efforts are induced. This is the reason why testing is often performed at component or subsystem levels, prior to complete system integration for final product testing.

In addition to vibration, shock, thermal vacuum, and acoustic testing, EMC testing is a necessary part of the qualification test sequence. EMC testing verifies the function of a device in its intended electromagnetic environment, from an emissions and susceptibility perspective. Emissions refers to the electromagnetic signatures emitted from the device, while susceptibility is a measure of the device’s response when subjected to an electromagnetic environment. Emissions and susceptibility are studied within the classifications of conducted and radiated behaviour. The spacecraft, and consequently all onboard subsystems, are not to produce electromagnetic interference (EMI) that may adversely affect either itself or the launch vehicle. In addition, the spacecraft must not be susceptible to emissions that may endanger its ability to perform the mission nominally and safely. This susceptibility condition covers both emissions from the spacecraft itself and from external sources.

EMC testing is performed in an anechoic chamber, like those designed and manufactured by Raymond EMC. In fact, Raymond EMC has experience building anechoic chambers for this very purpose of spacecraft testing.

EMC/EMI test requirements for spacecraft are typically derived from military test standards, and in particular, MIL-STD-461F: Requirements for the Control of Electromagnetic Interference Characteristics of Subsystems and Equipment. The test procedures are to be tailored and adapted to accommodate mission-specific requirements, including special attention for protecting sensitive and mission-critical instruments onboard. There are supplemental test standards that may be referenced including MIL-STD-461C, MIL-STD-464C, as well as guidelines and test methods published by NASA.

With environmental testing, it is possible to mitigate risk by verifying that a spacecraft can survive and operate nominally following exposure to the harsh conditions of launch and space. Testing at lower levels of assembly allows for issues to be identified early and with less time and monetary cost. When it comes to EMC testing, the goal is for the spacecraft to not interfere with itself, cause interference to other devices nearby, or be vulnerable to the electromagnetic environment. With proven experience building EMC chambers for spacecraft applications, Raymond EMC is a trusted supplier to the aerospace industry for all anechoic chamber needs.