James Heirtzler

Many near Earth spacecraft have had problems over the South Atlantic Anomaly.The figure shows where MODIS, NASA's premier remote sending instrument, was made inoperative on June 15, 2001 (the big red star). The smaller yellow dots are where TOPEX had problems during the years1992-1998. The contour lines are the strength of the geomagnetic field for the altitude of TOPEX (about 1000 km), calculated using the IGRF for 1995. The field strength is minimum over the South Atlantic Anomaly. It was possible to get MODIS back in operation after 16 days.