Abstract
The NPOESS Preparatory Project (NPP) spacecraft was launched on Oct. 28, 2011, and began the commissioning phase of several of its instruments shortly thereafter. One of these instruments, VIIRS, was found to exhibit a gradual but persistent decrease in the optical throughput of several bands, with the near-infrared bands being more affected than those in the visible. This paper will discuss the sequence of events and activities which identified the cause of the optical degradation and the current and expected future state of the optics.
VIIRS On-orbit Optical Anomaly
The NPOESS Preparatory Project (NPP) spacecraft was launched on Oct. 28, 2011, and began the commissioning phase of several of its instruments shortly thereafter. One of these instruments, VIIRS, was found to exhibit a gradual but persistent decrease in the optical throughput of several bands, with the near-infrared bands being more affected than those in the visible. This paper will discuss the sequence of events and activities which identified the cause of the optical degradation and the current and expected future state of the optics.