The Polaris Dawn crew, launched on 10 September, will travel into an oval-shaped orbit that extends as high as 1,400 kilometers from Earth. That’s well into the inner band of Earth’s Van Allen radiation belts, which begin at around 600 miles (1,000 kilometers) in altitude.
- The Van Allen radiation belt is a zone of energetic charged particles, most of which originate from the solar wind.
- According to NASA, the Earth’s magnetosphere traps the high energy radiation particles and shields the Earth from the solar storms and the constantly streaming solar wind that can damage technology as well as people living on Earth.
- These trapped particles form two belts of radiation, known as the Van Allen Belts, that surround the Earth like enormous donuts1.
- The outer belt is made up of billions of high-energy particles that originate from the Sun and the inner belt results from interactions of cosmic rays with Earth’s atmosphere.
- Astronauts must fly though the Van Allen Belts to reach outer space, so it is important to fly through this region quickly to limit their exposure to radiation.
- It is located beyond low-Earth orbit. These radiation belts were discovered in 1958 by astrophysicist James Van Allen.
- In 1968, NASA’s Apollo Mission 8 was the first crewed spaceship to fly beyond the Van Allen belts to orbit the Moon and then return to Earth.
- The most recent time humans have set foot on the Moon or traveled beyond low-Earth orbit was in 1972, during the final mission of the Apollo program, Apollo 17.
