The MODerate resolution Imaging Spectroradiometer flies on board the Earth Observing System (EOS) satellites Terra
and Aqua in a sun-synchronous orbit that crosses the equator at 10:30 AM and 2:30 PM, respectively, at a low earth orbit
(LEO) altitude of 705 km. Terra was launched on December 18,1999 and Aqua was launched on May 4, 2002. As the
MODIS instruments on board these satellites continue to operate beyond the design lifetime of six years, the cumulative
effect of the space environment on MODIS and its calibration is of increasing importance. There are several aspects of
the space environment that impact both the top of atmosphere (TOA) calibration and, therefore, the final science
products of MODIS. The south Atlantic anomaly (SAA), spacecraft drag, extreme radiative and thermal environment,
and the presence of orbital debris have the potential to significantly impact both MODIS and the spacecraft, either
directly or indirectly, possibly resulting in data loss. Efforts from the Terra and Aqua Flight Operations Teams (FOT),
the MODIS Instrument Operations Team (IOT), and the MODIS Characterization Support Team (MCST) prevent or
minimize external impact on the TOA calibrated data. This paper discusses specific effects of the space environment on
MODIS and how they are minimized.
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