  The Transiting Exoplanet Survey Satellite (TESS) will search for planets
transiting bright stars with Ic<13. TESS has been selected by NASA for launch
in 2018 as an Astrophysics Explorer mission, and is expected to discover a
thousand or more planets that are smaller in size than Neptune. TESS will
employ four wide-field optical charge-coupled device (CCD) cameras with a
band-pass of 650 nm-1050 nm to detect temporary drops in brightness of stars
due to planetary transits. The 1050 nm limit is set by the quantum efficiency
(QE) of the CCDs. The detector assembly consists of four back-illuminated MIT
Lincoln Laboratory CCID-80 devices. Each CCID-80 device consists of 2048x2048
imaging array and 2048x2048 frame store regions. Very precise on-ground
calibration and characterization of CCD detectors will significantly assist in
the analysis of the science data obtained in space. The characterization of the
absolute QE of the CCD detectors is a crucial part of the characterization
process because QE affects the performance of the CCD significantly over the
redder wavelengths at which TESS will be operating. An optical test bench with
significantly high photometric stability has been developed to perform precise
QE measurements. The design of the test setup along with key hardware,
methodology, and results from the test campaign are presented.
