Dr. Miles Bengtson was a graduate student at University of Colorado Boulder. Following graduation in 2020, Bengtson was offered a postdoctoral position at the AFRL Space Vehicles Directorate’s Spacecraft Charging and Instrument Calibration Lab, or SCICL, with the goal of bringing the multi-energy electron tool from proof of concept to operational status.
The harsh space environment in outer space can cause damage to objects. It includes proton radiation and energetic electron radiation.
“Researchers at AFRL have long been studying how spacecraft materials and components degrade and evolve over time in the space environment, and have developed technologies to help ensure that spacecraft will fulfill their mission lifetimes, despite prolonged operation in this extreme environment,” said Bengtson.
Materials testing is often done in vacuum chambers, where components and material samples are exposed to electron radiation from an electron source.
“The problem is that conventional multi-energy electron devices are monoenergetic only — they only emit electrons at one energy — whereas the space environment contains electrons distributed across all energies, simultaneously,” Bengtson said. “Therefore, the environment where spacecraft materials and components are tested is fundamentally different from the environment they operate in.”
AFRL’s multi-energy electron device will give researchers the ability to produce an energetic electron environment in a laboratory, which closely represents the actual space environment.
“The test capabilities we have developed at AFRL will provide scientists, developers, and manufacturers the ability to perform ‘test like you fly’ studies of how materials respond to energetic electron irradiation,” Bengtson said. “The ability to recreate the space electron flux environment with high fidelity in a laboratory, is an enabling technology for a variety of Air Force and Space Force needs, as well as commercial needs.”
There are many uses for a multi-energy electronic device.
- Laboratory testing enables accelerated adaptation of novel/advanced materials for use on spacecraft since relying only on heritage materials hinders the agile implementation of next-generation materials.
- It will be a useful tool to study material evolution, electric charging, and electrostatic discharge of satellites. This will show how satellite interactions can lead to anomalies.
- It is essential to understand how materials change over time in order to develop next-generation space domain awareness tools.
Bengtson related an example of how the understanding of materials used in spacecraft is assisted through this technology.
“The Spacecraft Charging and Instrument Calibration Lab studies how reflectance spectra from satellites can be used to remotely and passively characterize objects in space,” Bengtson said. “For example, the object called 2020SO was initially thought to be an asteroid passing near the Earth. Further research revealed that the object was made of stainless steel and not an asteroid material. However, it was discovered by studying the spectra of sunlight reflected from the object. This led to the realization the object was actually a spent Centaur rocket body from the Gemini era,” said Bengtson, noting “the multi-energy device enables accurate study of how reflectance spectra change with time on orbit, which was crucial for this endeavor.”
Ryan Hoffmann, the SCICL’s chief scientist, is proud of the technological advances his lab has made in studying materials for spacecraft to improve their robustness or resiliency and to develop space domain awareness tools.
The laboratory covers 5,000 square feet. It contains three large vacuum testing chambers, named Mumbo, Jumbo and ExB magnetized plasma device; a medium vacuum chamber called MiniMum; two bell jars, one for testing solar panel coverglasses under electron radiation and the other for measuring resistance to space materials.
“SCICL is a world-class research laboratory and our exploration into this multi-energy electron source is an example of the progress AFRL is making in the study of the space environment on spacecraft,” Hoffmann said. “Our team is at an advanced prototype stage in the development of the multi-energy electron device. I am excited to say, we have built two prototypes so far, that have demonstrated basic functionality, and are building an advanced prototype now, which will be very close to a fully operational model.”
About AFRL
The Department of the Air Force’s primary scientific research-development center is the Air Force Research Laboratory. The AFRL plays a key role in the development, integration and discovery of affordable warfighting technologies that can be used by our air, space, or cyberspace forces. AFRL has a diverse portfolio that includes science and technology, from basic research to advanced technology development. It employs more than 11,500 people in nine technology areas. For more information, please visit: www.afresearchlab.com.