Astro Aerospace, a strategic business unit of Northrop Grumman, has completed a major milestone in the development of the reflector boom assembly (RBA) for NASA's Soil Moisture Active Passive (SMAP) Mission. Astro Aerospace conducted the RBA Critical Design Review on Dec. 13-14, 2011.

The RBA is being developed for the SMAP Instrument; the SMAP instrument and mission is being developed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

The SMAP mission will provide global measurements of soil moisture and its freeze/thaw state. These measurements will be used to enhance understanding of processes that link the water, energy and carbon cycles, and to extend the capabilities of weather and climate prediction models.

SMAP data also will be used to quantify net carbon flux in boreal landscapes and to develop improved flood prediction and drought monitoring capabilities.

The SMAP observatory will be launched into a 680-kilometer near-polar, sun-synchronous orbit, with equator crossings at 6 a.m. and 6 p.m. and will provide science data over a three-year period. Astro Aerospace received a contract for the RBA in 2009.

The SMAP instrument consists of an AstroMesh reflector and a single feed horn shared by an L-Band radar and an L-Band radiometer.

The reflector spins about the zenith axis at up to 14.6 revolutions per minute (rpm), providing a conically scanning antenna beam with a surface incidence of approximately 40 degrees. Conical scanning the reflector produces a measurement swath of 1000 km that allows for global data acquisition every 2-3 days.

The spun portion of the RBA weighs nominally 108 pounds (49 kilograms) and the entire RBA, including launch restraint equipment, weighs less than 143 pounds (65 kilograms). The launch restraint equipment attaches the compact, stowed reflector to the side of the spacecraft for launch.

"We have a successful history of teaming with JPL on planetary missions, and passing this Critical Design Review indicates we are on the right path for another successful collaboration because of the expertise, performance and reliability we deliver," said Dan Hoyt, SMAP Reflector program manager for Astro Aerospace.

The AM-Lite class is the newest addition to the AstroMesh reflector family. It is optimized for smaller, 3-meter to 8-meter, deployed apertures and is inherently light, yet stiff enough to maintain its shape, spinning at 14.6 rpm. AM-Lite class qualification hardware has been tested with outstanding radio frequency performance at greater than 50 GHz.

Astro Aerospace has provided seven different AstroMesh reflectors to various customers ranging in size from nine to 12.25 meters that have all deployed successfully on-orbit and are performing flawlessly.