Editing South Atlantic Anomaly (section)

==Intensity and effects==
[[File:Mission Control center of NASA.png|thumb|left|The location of the SAA is visible on the main screen at NASA's Mission Control Center in Houston.]]
The South Atlantic Anomaly is of great significance to astronomical [[satellite]]s and other [[spacecraft]] that [[orbit]] the Earth at several hundred kilometers altitude; these orbits take satellites through the anomaly periodically, exposing them to several minutes of strong ionizing radiation, caused by the trapped protons in the inner Van Allen belt.

Measurements on [[Space Shuttle]] flight [[STS-94]] have ascertained that absorbed dose rates from charged particles have extended from 112 to 175 μGy/day, with dose equivalent rates ranging from 264.3 to 413 μSv/day.<ref>{{cite journal |last1=Badhwar |first1=G. D |last2=Kushin |first2=V. V |last3=Akatov |first3=Yu A |last4=Myltseva |first4=V. A |date=1999-06-01 |title=Effects of trapped proton flux anisotropy on dose rates in low Earth orbit |journal=Radiation Measurements |language=en |volume=30 |issue=3 |pages=415–426 |pmid=11543145 |issn=1350-4487 |doi=10.1016/S1350-4487(99)00068-2 |bibcode=1999RadM...30..415B |url=https://www.sciencedirect.com/science/article/abs/pii/S1350448799000682}}</ref>

The [[International Space Station]], orbiting with an [[inclination]] of 51.6°, requires extra shielding to deal with this problem. The [[Hubble Space Telescope]] does not take observations with its sensitive UV detectors while passing through the SAA.<ref>{{cite web |title=Hubble Achieves Milestone: 100,000th Exposure |publisher=[[Space Telescope Science Institute]] |date=July 18, 1996 |url=https://hubblesite.org/contents/news-releases/1996/news-1996-25.html |access-date=January 25, 2009}}</ref> Passing through the anomaly caused false alarms on [[Skylab]] [[Apollo Telescope Mount]]'s [[solar flare]] sensor.<ref name="elder">{{cite book |last=Elder |first=Donald C. |title=From Engineering Science to Big Science: The NACA and NASA Collier Trophy Research Project Winners |publisher=NASA |year=1998 |editor-last=Mack |editor-first=Pamela E. |series=The NASA History Series |chapter=The Human Touch: The History of the Skylab Program |id=SP-4219 |url=https://history.nasa.gov/SP-4219/Contents.html |chapter-url=https://history.nasa.gov/SP-4219/Chapter9.html}}</ref> Astronauts are also affected by this region, which is said to be the cause of peculiar "shooting stars" ([[phosphene]]s) seen in the visual field of astronauts, an effect termed [[cosmic ray visual phenomena]].<ref name="AskA">{{cite web |title=What is the South Atlantic Anomaly? |work=Ask the Astronomer |url=http://www.astronomycafe.net/qadir/q525.html |access-date=December 6, 2009}}</ref> Passing through the South Atlantic Anomaly is thought to be the reason for the [[Globalstar#First-generation satellite problems|failures of the Globalstar network's satellites]] in 2007.<ref>{{cite web |title=Space Intelligence News |publisher=Ascend |date=March 2007 |url=http://www.ascendworldwide.com/content/spacetrak/sinsample.pdf |url-status=dead |archive-url=https://web.archive.org/web/20070214142051/http://www.ascendworldwide.com/content/spacetrak/sinsample.pdf |archive-date=2007-02-14}}</ref>

The [[PAMELA detector|PAMELA]] experiment, while passing through the SAA, detected [[antiproton]] levels that were orders of magnitude higher than expected. This suggests the Van Allen belt confines antiparticles produced by the interaction of the Earth's upper atmosphere with [[cosmic ray]]s.<ref>{{cite journal |title=The Discovery of Geomagnetically Trapped Cosmic-Ray Antiprotons |journal=The Astrophysical Journal Letters |last1=Adriani |first1=O. |last2=Barbarino |first2=G. C. |last3=Bazilevskaya |first3=G. A. |last4=Bellotti |first4=R. |last5=Boezio |first5=M. |last6=Bogomolov |first6=E. A. |last7=Bongi |first7=M. |last8=Bonvicini |first8=V. |last9=Borisov |first9=S. |last10=Bottai |first10=S. |last11=Bruno |first11=A. |last12=Cafagna |first12=F. |last13=Campana |first13=D. |last14=Carbone |first14=R. |last15=Carlson |first15=P. |last16=Casolino |first16=M. |last17=Castellini |first17=G. |last18=Consiglio |first18=L. |last19=De Pascale |first19=M. P. |last20=De Santis |first20=C. |last21=De Simone |first21=N. |last22=Di Felice |first22=V. |last23=Galper |first23=A. M. |last24=Gillard |first24=W. |last25=Grishantseva |first25=L. |last26=Jerse |first26=G. |last27=Karelin |first27=A. V. |last28=Kheymits |first28=M. D. |last29=Koldashov |first29=S. V. |last30=Krutkov |first30=S. Y. |display-authors=5 |volume=737 |issue=2 |at=L29 |date=August 2011 |doi=10.1088/2041-8205/737/2/L29 |bibcode=2011ApJ...737L..29A |arxiv=1107.4882}}</ref>

NASA has reported that modern laptop computers have crashed when [[Space Shuttle]] flights passed through the anomaly.<ref>{{cite web |title=Shuttle Computers Navigate Record of Reliability |publisher=NASA |last=Siceloff |first=Steven |date=June 28, 2010 |url=http://www.nasa.gov/mission_pages/shuttle/flyout/flyfeature_shuttlecomputers.html |access-date=July 3, 2010}}</ref>

In October 2012, the [[SpaceX CRS-1]] Dragon spacecraft attached to the International Space Station experienced a transient problem as it passed through the anomaly.<ref>{{cite news |title=Dragon enjoying ISS stay, despite minor issues |work=NASA Spaceflight |last=Bergin |first=Chris |date=October 19, 2012 |url=https://www.nasaspaceflight.com/2012/10/dragon-iss-stay-minor-issues-falcon-9-investigation/ |access-date=October 20, 2012}}</ref>

The SAA is believed to have started a series of events leading to the destruction of the [[Hitomi (satellite)|Hitomi]], Japan's most powerful X-ray observatory.  The anomaly transiently disabled a direction-finding mechanism, causing the satellite to rely solely on gyroscopes that were not working properly, after which it spun out of control, losing its solar panels in the process.<ref>{{cite news |title=Japan's most powerful X-ray satellite is dead |work=[[Engadget]] |last=Moon |first=Mariella |date=April 29, 2016 |url=https://www.engadget.com/2016-04-29-rip-hitomi.html |access-date=April 29, 2016}}</ref>