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Part 2 of 2 Parts (Please read Part 1 first)
     Putting a RBR platform in space closer to the target would be more effective than Earth-bases solutions. In June of 2019, the U.S. Air Force launched DASX dipole antenna, the largest uncrewed structure to ever fly in space. It is about the length of a U.S. football field. The primary mission of the DSX is to transmit VLF waves into the Van Allen radiation belts and measure the precipitating particles with detectors on the DSX. James McCollough at the Air Force Research Laboratory is the primary DSX investigator. He said, “It’s a new way to prod the belts and explore basic questions in space physics.”
     A team of researchers at Los Alamos and NASA’s Goddard Space Flight Center is heading up a second experiment to cause VLF precipitation. In April of 2021, the team intends to launch a sounding rocket carrying the Beam Plasma Interaction Experiment. This is a miniature accelerator that would generate a beam of electrons which would result in VLF waves that should be able to sweep particles out of the radiation belts. Reeves is leading the experiment. He believes that the small accelerators might prove to be a better “broom” for sweeping particles that a huge VLF antenna. He said, “If we validate it with this experiment, we have a lot more confidence we can scale it up to higher power.”
    A third experiment would try to cause the atmosphere itself to generate turbulent radio waves that would draw down the high-energy electrons from the radiation belts. In the summer of 2021, the U.S. Naval Research Laboratory plans to launch the Space Measurements of a Rocket-Released Turbulence mission. A sounding rocket will be launched into the ionosphere which is an atmospheric layer hundreds of miles above the Earth’s surface. That layer is full of electrons and ions. The probe will throw out about three pounds of barium atoms. When the barium atoms are ionized by sunlight, they will create a moving ring of plasma that will emit radio waves. This is equivalent to a space version of a magnetron which is the device that generates microwaves for a microwave oven.
     These three missions will help researchers identify which RBR system is most practical. Any operational system based on these technologies will still be years away. Any of the technologies ultimately selected for implementation will carry risks. It is possible that any full-scale attempt to clean up the high-energy electrons could dump as much energy into the upper atmosphere as is dumped by intense solar flares. That could disrupt navigation and communication for commercial airliners. It would also create a lot of nitrogen and hydrogen oxides which could eat holes in the ozone layer. Allison Jaynes is a space physicist at the University of Iowa. She said, “We don’t know how great the effect would be.”
     In addition to protection against a nuclear space detonation, there may be additional benefits to the RBR technology. NASA scientists have grappled for decades with the dangers of radiation to astronauts as they pass through radiation belts and other sources of radiation. VLF transmitters might be used to clear a path through the radiation belts just prior to the launch of a mission. Jaynes says, “When we become more active space travelers, it could provide a safe passage through the radiation belts.”