Solar cells, integrated circuits, and sensors can be damaged by radiation. In 1962, the Van Allen belts were temporarily amplified by a high-altitude nuclear explosion (the Starfish Prime test) and several satellites ceased operation. Magnetic storms occasionally damage electronic components on spacecraft. Miniaturization and digitization of electronics and logic circuits have made satellites more vulnerable to radiation, as incoming ions may be as large as the circuit's charge. Electronics on satellites must be hardened against radiation to operate reliably. The Hubble Space Telescope, among other satellites, often has its sensors turned off when passing through regions of intense radiation. An object satellite shielded by 3 mm of aluminum will receive about 2500 rem (25 Sv) per year.[5] Proponents of the Apollo Moon Landing Hoax have argued that space travel to the moon is impossible because the Van Allen radiation would kill or incapacitate an astronaut who made the trip. James Van Allen himself, now deceased (August 9, 2006), dismissed these ideas. In practice, Apollo astronauts who travelled to the moon spent very little time in the belts and received a harmless dose [6]. Nevertheless NASA deliberately timed Apollo launches, and used lunar transfer orbits that only skirted the edge of the belt over the equator to minimize the radiation. Astronauts who visited the moon probably have a slightly higher risk of cancer during their lifetimes, but still remain unlikely to become ill because of it.
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