Major concerns in vacuum environments include outgassing, multipaction, and whiskering

Vacuum Challenges for Demanding Space Applications

Outgassing

Many non-metallic materials outgas when exposed to a vacuum environment, including plastics commonly found in coaxial cables, such as PTFE, PVC, and PE. Emitted gases can recondense on critical components such as camera lenses, degrading performance. As a result, NASA and the European Space Agency (ESA) have developed standards to define outgassing rates and databases to compile the performance of various materials.

Multipaction

Multipaction (also known as the multipactor effect) is an electron resonance effect that occurs when RF fields accelerate electrons in a vacuum and cause them to impact with a surface, which depending on its energy, releases one or more electrons into the vacuum. When the electrons release and timing of the impacts are such that a sustained multiplication of the number of electrons occurs, it can lead to loss and distortion of the RF signal and even result in damage to the RF components or subsystems.

In RF cable assemblies, multipaction can occur at the connector between the inner and outer conductors. Our engineers mitigate multipaction risks by designing mating connectors with overlapping dielectrics to remove any free path between conductors.

Whiskering

Tin is commonly used in solder for coaxial connectors and plating of semi-rigid coaxial cables. Metals such as pure tin can grow whiskers in a vacuum and high-temperature environments, leading to shorts or FOD, and are generally prohibited from spaceflight use. To avoid whiskering, designers should specify tin/lead alloys for solder or plating.

 

Related Products

MaxGain®    PhaseTrack®     Semi-Rigid     SiO2     SpaceFlight

MaxGain®

MaxGain® is an ultra-low loss, flexible microwave coaxial cable with a full range of connectors available as fully tested custom cable assemblies.

PhaseTrack®

PhaseTrack® cable assemblies are designed for applications demanding minimal phase change over temperature. All PhaseTrack cables use a proprietary TF4™ dielectric that does not have the abrupt shift in the phase that occurs with solid- or tape-wrapped PTFE-based products under normal room ambient temperature conditions.

Semi-Rigid

Semi-Rigid cable assemblies are optimized for phase performance under harsh enviroments. They are available in sizes commonly used in most in-box applications and are compatible with many connectors.

SiO2

The SiO2 semi-rigid cable assemblies are used in applications demanding the ultimate in phase tracking performance and extreme environments.

SpaceFlight

The SpaceFlight product line embodies the critical requirements necessary for reliable performance in space. Our proprietary material conditioning and vacuum testing of assemblies ensure outgassing is minimized to meet NASA standards ASTM E‐595.