Description: MMA has proposed a technical approach creates a highly simplistic antenna architecture by taking advantage of natural mechanics of high-strain composite materials to create a 1D parabolic reflector surface. At smaller scales (1-2 m2), the architecture allows continuous reflector surfaces for ESPA-class spacecraft, while at larger scales a modular architecture is taken advantage of to produce much larger apertures without requiring comparatively large spacecraft. The effort will develop a large aperture at Ku, Ka, and W frequencies using rollable shell surfaces that combine the surface accuracy of rigid reflectors with the packaging advantages of flexible reflectors. Developing a stowable, “morphing”, high-strain composite reflector surface with sufficient surface roughness and position knowledge for frequencies up to 94 GHz will enable large apertures with reduced stowed envelope and can dramatically reduce the hardware, instrument and mission implementation costs. Originally inspired by the shape of a beam being deflected under load, MMA is using analysis and lab testing to determine the prescribed loading configuration capable of deflecting a semi-rigid member into a parabolic curve. By using the mechanics of bending rather than molding and manufacturing to prescribe the reflector’s shape, the system provides a repeatable method of forming a parabolic surface. This architecture lends itself to a structurally simple system, providing high reliability and low complexity. Phase I efforts demonstrated through analysis and prototyping that loading conditions exist for isotropic beams to form a surface closely matching a parabola, while RF performance simulations verified the reflector’s ability to perform with minimal gain losses up to 95 GHz. The phase II effort will build upon this early development to design, build, and test a deployable tri-band antenna system.

Benefits: NASA utilizes multi-band radar for precipitation and moisture related weather monitoring instruments. Recent missions have incorporated large, expensive antenna systems that drive large mission costs such as the Global Precipitation Measurement Mission ($1B). The availability of a relatively large aperture (2 square meters) that performs at Ku/Ka/W frequencies but can stow in a small volume (~.001 cubic meters) enables missions to be conducted on much smaller, less expensive satellite platforms (300-400 kg ESPA/ESPA Grande) that can be launched as secondary payloads on larger rockets, or utilize many of the emerging lower cost rockets for a dedicated launch. This approach supports rapid deployment of experimental missions as well a mission which utilizes multiple satellites in a constellation to provide faster revisit times and also enables instrument upgrades and rapid, low cost replacement/replenishment. The broad frequency capabilities of this antenna technology also support commercialization into other RF applications required by NASA including communications, other applications of RF remote sensing and imaging, etc.

The same economic drivers that support NASA commercialization of this technology apply to non-NASA markets. The DoD, foreign countries, and commercial interests are all in need of improved, timely weather data. The U.S. military has expressed interest in smaller, lower cost, dis-aggregated satellite system architectures that support rapid upgrades and replacements. This technology can support such efforts in precipitation measurement, hurricanes, ocean surface winds and many more weather needs with more accurate and timely data availability from low earth orbits. Many countries suffer the negative effects of typhoons and hurricanes and actively fund low cost weather satellite missions that can be greatly enhanced by this antenna technology. Commercial entities are also potential data consumers for such efforts as disaster relief and assessments of weather damage, agricultural impacts, etc. As mentioned above, the wide band capability of this technology also supports a wide range of other RF applications that will also drive commercialization of this antenna/reflector technology.