NASA SBIR 2005 Solicitation


SUBTOPIC TITLE:Energy Conversion and Storage for Space Applications
PROPOSAL TITLE:Affordable High Performance Electromagnetically Clean Solar Arrays

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
DR Technologies, Inc
7740 Kenamar Court
San Diego ,CA 92121 - 2425
(858) 677 - 1226

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Theodore  G. Stern
7740 Kenamar Court
San Diego, CA  92121 -2425
(858) 677 - 1230

We propose an Electromagnetically Clean Solar Array (ECSA) with enhanced performance, in Watts/kg and Watts/m2, using flight proven, high efficiency solar cells. For electrostatic cleanliness, our innovation is to use large flat sheets of specially processed environmentally durable, ITO-coated DC93-500 transparent silicone material to replace the multitude of coverglasses and grounding components on a solar panel. For magnetic environments, we propose the use of a Kapton layer with a printed wiring pattern that mirrors the solar cell string to cancel magnetic moments. This metallized Kapton layer would replace the bare Kapton normally used as the solar panel substrate insulating front surface. A key innovation is to reduce the cost of solar panels by adapting the transparent shielding layer and the printed circuit layer with features to assemble solar cells into completely connected and wired panels using lamination. Features built into the layers position the Cell-Interconnect (CI) assemblies, solder pre-forms and wiring connections, allowing a one step process for "glassing," stringing, laydown and wiring. This eliminates the most costly labor and schedule intensive elements of conventional solar panel assembly. This research directly addresses the topic needs of providing electrostatic and magnetic cleanliness and affordability for flight proven solar panel technology.

Electromagnetic cleanliness is needed for missions that use sensitive instruments, including magnetometers and electric field instruments. Current and future missions such as NASA's THEMIS (Time History of Events and Macroscale Interactions during Substorms) and MMS (Magnetosphere Multi-Scale) spacecraft, have instruments so sensitive that the electric and magnetic fields generated by the solar array can overwhelm the instruments' measurements. This research promises significant improvement in electrostatic and magnetic noise signatures in solar arrays, which could enable more sensitive measurements than are currently possible. The need for lower cost methods for assembling solar arrays, which is a by-product of this research, has applicability across nearly all of NASA's missions, since solar array costs contribute significantly to total mission cost, and the ability to currently reduce these costs is limited by the "standard way of doing business." Schedule reduction has been identified by NASA as a need for spacecraft bus power systems, and the proposed modular approach together with other schedule reduction features, will allow a significant reduction in turn-around time from mission conception to solar array delivery.

The same features that provide electromagnetic cleanliness will increase durability of commercial solar arrays in space against radiation, debris, ion thruster plumes and other degradation factors. This improved durability, together with the cost and schedule reductions being developed by this SBIR will lead to opportunities with commercial spacecraft power systems. Communications spacecraft need higher and higher power arrays as the number of transponders and communication traffic grows. The spacecraft providers for these missions are driven primarily by cost, durability and tight schedules, although state-of-the-art performance is important as well. For a typical 20kW spacecraft, the solar arrays can comprise 20% of the total spacecraft cost. A modular panel that reduces piecepart count and assembly costs by 1/3 would provide the spacecraft integrator with a significant competitive advantage. Longer lives are also being demanded by commercial spacecraft operators, and the additional shielding will allow improved resistance to degrading factors in space.

NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.

Optical & Photonic Materials
Photovoltaic Conversion

Form Printed on 09-19-05 13:12