The Global Precipitation Measurement (GPM) spacecraft was jointly developed by National Aeronautics and Space Administration (NASA) and Japan Aerospace Exploration Agency (JAXA). It is a Low Earth Orbit (LEO) spacecraft launched on February 27, 2014. The spacecraft is in a circular 400 Km altitude, 65 degrees inclination nadir pointing orbit with a three year basic mission life. The solar array consists of two sun tracking wings with cable wraps. The panels are populated with triple junction cells of nominal 29.5% efficiency. One axis is canted by 52 degrees to provide power to the spacecraft at high beta angles. The power system is a Direct Energy Transfer (DET) system designed to support 1950 Watts orbit average power. The batteries use SONY 18650HC cells and consist of three 8s x 84p batteries operated in parallel as a single battery.The paper describes the power system design details, its performance to date and the lithium ion battery model that was developed for use in the energy balance analysis and is being used to predict the on-orbit health of the battery.

This paper presents an integrating of highly transparent X band reflectarray on the cover glass of solar panels. Two types of element geometries are studied, and optimal unit cell element, effect of the solar cell on the antenna, feed consideration, and final design data are presented. The overall transparency and aperture efficiency of the design are more than 90% and 40% respectively, making it a promising solution as a high gain conformal satellite antenna.

Emcore's latest generation InGaP/InGaAs/Ge ZTJ triple-junction space-grade high-efficiency solar cells have been in volume production since 2009, with over 300,000 flight cells produced to power more than 35 separate satellites. The ZTJ cells, CICs (Coverglass-Interconnected-Cell) and solar panels have also been characterized and qualified to both the AIAA-S-111 and AIAA-S-112 standards. More than 10 life-cycle coupon panels have been thermal cycled to temperature extremes representing varied orbital conditions such as GEO (geosynchronous), LEO (low-earth) and highly elliptical orbits. In its larger 1-cell-per-wafer form factor, the ZTJ solar cell has been used to manufacture solar panels for a dozen NASA and other commercial spacecraft. Currently Emcore Photovoltaics is under contract to NASA's Goddard Space Flight Center (GSFC) to build and deliver the solar panels for the Magnetospheric Multiscale (MMS) Mission and to ATK Space Systems for the Commercial Resupply (CRS) mission to the International Space Station (ISS) and the AMOS-6 commercial telecommunication satellite. In this paper, the results of the qualification, production and testing of the life-cycle coupons and the solar panels for these missions is presented. In addition, the initial on-orbit telemetry performance results of NASA's NuStar (Nuclear Spectroscopic Telescope Array) spacecraft solar array will be presented. The NuStar spacecraft was launched in June of 2012 and built by Orbital Sciences Corporation It is powered by an ATK solar array populated with ZTJ solar cells.