Today, the context is alarmingly relevant. North Korea’s possession of nuclear weapons, coupled with its absence of satellites, prompts defense scientists to consider a surprise orbital blast a “Pearl Harbor of space.” In response, the U.S. military is quietly but urgently exploring Radiation Belt Remediation (RBR) technologies. One such endeavor is the recently launched DSX dipole antenna by the U.S. Air Force, which aims to beam very low frequency (VLF) waves into the radiation belts to precipitate high-energy electrons.
The idea stems from the natural process where radio waves from space or lightning on Earth disturb trapped electrons, causing them to dive into the upper atmosphere and rapidly lose energy, often triggering auroras. James McCollough, the principal investigator of DSX, sees the project as “a new way to prod the belts and explore basic questions in space physics.” Complementing DSX are two experiments scheduled for launch in 2021: the Beam Plasma Interactions Experiment, a miniature accelerator that could act as a more compact solution for sweeping up particles, and the Space Measurements of a Rocket-Released Turbulence mission, which will use ionized barium to generate radio waves and draw down electrons.
The initiatives stem from a deepened understanding of wave-particle interactions in the Van Allen belts, enriched by data from NASA’s Van Allen Probes. Geoff Reeves, a space physicist at Los Alamos National Laboratory, noted, “Compared to 10 years ago, we just know so much more about how these wave-particle interactions work.”
However, the implications of such technologies are not without concerns. They bear the potential to unleash as much energy into the atmosphere as solar eruptions do, possibly affecting navigation and communication systems, not to mention the creation of nitrogen oxides and hydrogen oxides, which threaten the ozone layer. Space physicist Allison Jaynes emphasizes, “We don’t know how great the effect would be.”
Beyond military applications, the civilian benefits of RBR could be significant. Shielding astronauts from radiation en route to deep space is a longstanding challenge for NASA and other space agencies. VLF transmitters might be used to clear out high-energy electrons before spacecraft enter danger zones. As Jaynes puts it, “When we become more active space travelers, it could provide a safe passage through the radiation belts.”
Relevant articles:
– U.S. tests ways to sweep space clean of radiation after nuclear attack, Science | AAAS
– Going Nuclear Over the Pacific, Smithsonian Magazine
– A Very Scary Light Show: Exploding H-Bombs In Space, NPR
– Getting Serious about the Threat of High Altitude Nuclear Detonations, War on the Rocks