Kurland, Richard | Engineering Papers

NASA NTRS2000

Terra Flexible Blanket Solar Array Deployment, On-Orbit Performance and Future Applications

The Terra spacecraft (formerly identified as EOS AM1) is the flagship in a planned series of NASA/GSFC (Goddard Space Flight Center) Earth observing system satellites designed to provide information on the health of the Earth's land, oceans, air, ice, and life as a total ecological global system. It has been successfully performing its mission since a late-December 1999 launch into a 705 km polar orbit. The spacecraft is powered by a single wing, flexible blanket array using single junction (SJ) gallium arsenide/germanium (GaAs/Ge) solar cells sized to provide five year end-of-life (EOL) power of greater than 5000 watts at 127 volts. It is currently the highest voltage and power operational flexible blanket array with GaAs/Ge cells. This paper briefly describes the wing design as a basis for discussing the operation of the electronics and mechanisms used to achieve successful on-orbit deployment. Its orbital electrical performance to date will be presented and compared to analytical predictions based on ground qualification testing. The paper concludes with a brief section on future applications and performance trends using advanced multi-junction cells and weight-efficient mechanical components.

Kurland, Richard↗

NASA NTRS2000

Terra Flexible Blanket Solar Array Deployment, On-Orbit Performance and Future Applications

The Terra spacecraft (formerly identified as EOS AM1) is the flagship in a planned series of NASA/GSFC (Goddard Space Flight Center) Earth observing system satellites designed to provide information on the health of the Earth's land, oceans, air, ice, and life as a total ecological global system. It has been successfully performing its mission since a late-December 1999 launch into a 705 km polar orbit. The spacecraft is powered by a single wing, flexible blanket array using single junction (SJ) gallium arsenide/germanium (GaAs/Ge) solar cells sized to provide five year end-of-life (EOL) power of greater than 5000 watts at 127 volts. It is currently the highest voltage and power operational flexible blanket array with GaAs/Ge cells. This paper briefly describes the wing design as a basis for discussing the operation of the electronics and mechanisms used to achieve successful on-orbit deployment. Its orbital electrical performance to date will be presented and compared to analytical predictions based on ground qualification testing. The paper concludes with a brief section on future applications and performance trends using advanced multi-junction cells and weight-efficient mechanical components. A viewgraph presentation is attached that outlines the same information as the paper and includes more images of the Terra Spacecraft and its components.

Kurland, Richard↗

NASA NTRS1992

Advanced photovoltaic solar array - Design and performance

This paper reports on the development of an ultralightweight flexible blanket, flatpack, foldout solar array design that can provide 3- to 4-fold improvement on specific power performance of current rigid panel arrays and a factor of two improvement over a first-generation flexible blanket array developed as a forerunner to the Space Station Freedom array. To date a prototype wing has been built with a projected specific power performance of about 138 W/kg at beginning-of-life (BOL) and 93 W/kg end-of-life (EOL) at 12 kW (BOL) for a 10-year geosynchronous (GEO) mission. The prototype wing hardware has been subjected to a series of system-level tests to demonstrate design feasibility. The design of the array is summarized. The major trade studies that led to the selection of the baseline design are discussed. Key system-level and component-level testing are described. Array-level performance projections are presented as a function of existing and advanced solar array component technology for various mission applications.

Kurland, Richard↗

NASA NTRS1988

Status of Advanced Photovoltaic Solar Array program

The current development status of ultralightweight flexible-blanket foldout solar arrays being designed and fabricated under the NASA Advanced Photovoltaic Solar Array (APSA) program is surveyed. The goal of APSA is the construction of a 25-kW array with specific power 300 W/kg (BOL) by the year 2000. Topics discussed here include array configurations, blanket deployment systems, prototype wing-hardware fabrication, component-level test results, solar-cell technologies, and array performance estimates. Diagrams, drawings, graphs, and tables of numerical data are provided.

Kurland, Richard↗

NASA NTRS1987

Advanced photovoltaic solar array design

An ultralightweight flexible-blanket flatpack, foldout solar array design is defined. The design establishes a critical intermediate milestone of the NASA high-performance Advanced Photovoltaic Solar Array program through its primary objective of realistically demonstrating a solar array that can provide greater than 130 W/kg at beginning of life (BOL) and 100 W/kg at end of life for a 10-year geosynchronous 10-kW (BOL) space power system. This paper reviews the critical features of the preliminary design and the implications for long-term array technology development.

Kurland, Richard↗