Modern multijunction (MJ) solar cells require stable optical coatings that provide wider spectral
protection. The requirement to transmit shorter wavelengths to the top cell of the MJ device
imposed new challenges for coatings. Ultraviolet reflection (UVR) and wide-band antireflection
(AR) multilayer coatings were applied on working solar cell covers and test substrates and
subsequently exposed in space on MISSE-7 along with space-simulated ground tests to
determine their performance and stability. Observed effects of long space exposure on the
coatings and assembled solar cells were small. UVR/AR coatings showed stable optical
properties after exposure to proton, UV, atomic oxygen, and protected flexible polymer
substrate materials. The technology for producing effective space-mission coatings that operate
to UV wavelengths near 200 nm was successfully demonstrated. Further development is
pending, including more exposure tests of UVR, AR, and transparent conductive oxide (TCO)
coatings on flexible substrate alternatives and coatings integrated with MJ cells. Progress was
made toward developing stable and protective coatings with improved resistance to radiation-
induced darkening for extended space-mission applications. The additional requirements that
the coatings on MJ flexible solar arrays tolerate deployment from being rolled up, and prevent
static accumulation and discharge, were also satisfied.
PUBLICATION(S)
Prokop NF, Greer LC, Krasowski MJ, Flatico JM, Spina DC. A miniature microcontroller curve
tracing circuit for space flight testing transistors. Review of Scientific Instruments. February
2015;86:024707. doi: 10.1063/1.4908163.
Pellicori SF, Martinex CL, Hausgen P, Wilt D. Development and testing of coatings for orbital
space radiation environments. Applied Optics. February 1, 2014;53(4):A339-350. doi: 10.1364/
AO.53.00A339.
Krasowski MJ, Prokop NF, Flatico JM, et al. CIB: An improved communication architecture for
real-time monitoring of aerospace materials, instruments, and sensors on the ISS. The Scientific
World Journal. 2013;2013(185769):12 pp. doi: 185769.
Gaier JR, Baldwin S, Folz A, et al. Degradation of spacesuit fabrics on low Earth orbit. NASA
Technical Memorandum; August 2012.
Gaier JR, Waters DL, Jaworske DA, et al. Post-flight characterization of samples for the MISSE-7
spacesuit fabric exposure experiment. NASA Technical Memorandum; August 2012.
This investigation is complete; however, additional results are pending publication.