TechSat 21 and Revolutionizing Space Missions using Microsatellites

The Air Force Research Laboratory (AFRL) TechSat 21 flight experiment demonstrates a formation of three microsatellites flying in formation to operate as a “virtual satellite.” X-band transmit and receive payloads on each of the satellites form a large sparse aperture system. The satellite formation can be configured to optimize such varied missions as radio frequency (RF) sparse aperture imaging, precision geolocation, ground moving target indication (GMTI), single-pass digital terrain elevation data (DTED), electronic protection, single-pass interferometric synthetic aperture radar (IF-SAR), and high data-rate, secure communications. Benefits of such a microsatellite formation over single large satellites include unlimited aperture size and geometry, greater launch flexibility, higher system reliability, easier system upgrade, and low cost mass production. Key research has focused on the areas of formation flying and sparse aperture signal processing and been sponsored and guided by the Air Force Office of Scientific Research (AFOSR). The TechSat 21 Program Preliminary Design Review (PDR) was held in April 2001 and incorporated the results of extensive system trades to achieve a light-weight, high performance satellite design. An overview of experiment objectives, research advances, and satellite design is presented

Economic and Environmental Costs and Benefits of Living Snow Fences: Safety, Mobility, and Transportation Authority Benefits, Farmer Costs, and Carbon Impacts

Blowing and drifting snow on Minnesota's roadways is a transportation efficiency and safety concern. Establishing standing corn rows and living snow fences improves driver visibility, road surface conditions, and has the potential to lower costs of road maintenance as well as accidents attributed to blowing and drifting snow. It also has the potential to sequester carbon and avoid the carbon emissions of snow removal operations. In recent years the Minnesota Department of Transportation (MnDOT) has paid farmers to leave standing corn rows to protect identified snow problem roadways. They have paid farmers $1.50 per bushel above market price. With increasing demand for corn to fuel the ethanol industry, paying$1.50 per bushel above market price may not be sufficient incentive for leaving standing corn rows. Also, with MnDOT’s memorandum of understanding with USDA to plant living snow fences through the Conservation Reserve Program (CRP), now is an opportune time to review MnDOT’s annual payment structure to farmers and prepare a new one. This project has: 1) developed a calculator to estimate payments for farmers that includes consideration of safety and snow removal cost savings; 2) estimated potential income from carbon payments; 3) worked closely with MnDOT engineers and plow operators, estimated the safety and snow removal costs and carbon emissions avoided by MnDOT through establishing living snow fences; and 4) evaluated farmers’ willingness to establish living snow fences and identified farmers/landowners’ constraints to adoption. Data is provided to MnDOT to assist staff in its decision making related to their Living Snow Fence Program.University of Minnesota Extension; Minnesota Department of Transportatio