It's also why astronauts wear dosimeters (devices that measure their personal exposure to ionising radiation in real time) that send out a warning if they reach dangerous levels. Indeed, the SAA is why strong shielding is in place over the most frequently occupied parts of the International Space Station (ISS), such as the gallery and the sleeping quarters, reducing the amount of radiation the astronauts are exposed to. "Putting equipment into a 'safe mode' means operations that are more vulnerable to radiation are curtailed," Tarduno said. Related: 'Vigorous' magnetic field oddity spotted over South Atlantic (opens in new tab)Īstronauts have also witnessed problems with computers on board spacecraft that fly in the vicinity of the SAA. Satellites using the microwave tracking system DORIS - which stands for Doppler Orbitography and Radiopositioning Integrated by Satellite - for example, see a resulting shift of the onboard oscillator frequency. Failing to take precautions would likely lead to system failure.Ĭertainly, the more complex electronics have become, the more potential there is for problems to emerge. Hubble is unable to collect astronomical data during these moments, which is not ideal, but necessary. Shutdowns protect many important studies, including those using the Hubble Space T telescope, which passes through the SAA 10 times a day, spending a good 15% of its time there.
To protect them from potential hardware damage, space agencies and other satellite operators power them down so that the anomaly doesn't end up knocking out onboard computers and interfere with data collection. The low altitude of the radiation hotspot, however, puts it within the orbit of certain satellites, which become bombarded by protons that exceed energies of 10 million electron volts (eV) at a rate of 3,000 "hits" per square centimetersr per second.Īs Tarduno pointed out, this affects the spacecraft's onboard electronic systems, which hampers the operation of these objects. Ordinarily the Van Allen belts stretch at an altitude of between 1,000 and 60,000 km (620 and 37,000 miles(1,000 and 60,000 km) above Earth's surface. What happens to spacecraft and astronauts in the South Atlantic Anomaly? Īll About Space (opens in new tab) magazine takes you on an awe-inspiring journey through our solar system and beyond, from the amazing technology and spacecraft that enables humanity to venture into orbit, to the complexities of space science. This article is brought to you by All About Space (opens in new tab). With more incoming radiation, a satellite can become charged, and attendant arcs can result in serious damage." “Think about an electrical discharge or arc. "Satellites passing through this region will experience higher amounts of radiation to the point that damage could occur," Tarduno told All About Space. This causes problems with communications satellites and other equipment because the lower magnetic field intensity allows Earth's radiation belt - technically the inner Van Allen radiation belt - to come closer to Earth's surface. "I'm not fond of the nickname, but in that region, the lower geomagnetic field intensity eventually results in a greater vulnerability of satellites to energetic particles, to the point that spacecraft damage could occur as they traverse the area," said John Tarduno, professor of geophysics at the University of Rochester. As a result, solar rays come as close as 124 miles (200 kilometers (124 miles) to the Earth's surface and the more intense solar radiation results in an increased flux of energetic particles in this area. At the location of the SAA, however, the particles of solar cosmic rays are not being held back to the same extent as they are elsewhere above the planet.
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