Jan 22, 2018
On January 16-17, the mission team conducted a stray light characterization activity involving the OCAMS (OSIRIS-REx Camera Suite) instrument and the TAGCAMS navigation cameras.
Stray light occurs whenever sunlight shines on the OSIRIS-REx science deck and the sun’s rays bounce off its taller structures, such as PolyCam, OTES, and the Sample Return Capsule. Through a series of second, third and higher-level reflections, this redirected light finds its way into the cameras’ fields of view and produces glare in the images, especially for long exposures.
The goal of the stray light test is to study and determine the direction and amount of unwanted light that is scattered into the cameras. The Image Processing Working Group uses these stray-light background patterns to correct images that are acquired when the science deck points toward the Sun, such as during the search for possible dust and gas plumes around Bennu.
The amount of stray light that the spacecraft’s cameras have detected is within normal system performance requirements. This stray light characterization study is simply an effort to understand the behavior of the system in flight in the real space environment, which couldn’t be fully realized on the ground or in computer simulations before launch.