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NASA Breaking News

03/08/10 NASA Launches Interactive Simulation of Satellite Communications

NASA today unveiled an interactive computer simulation that allows virtual explorers of all ages to dock the space shuttle at the International Space Station, experience a virtual trip to Mars or a lunar impact, and explore images of star formations taken by the Hubble Space Telescope.

03/08/10 NASA Extends Johnson Safety and Mission Assurance Contract

NASA has exercised a $60 million, one-year extension option for a contract with Science Applications International Corporation of Houston to provide support to safety and mission assurance activities at the agency's Johnson Space Center.

03/07/10 NASA Hosts First-Ever Water Sustainability Forum March 16 -18

NASA today announced its founding partnership of Launch, an initiative to identify, showcase and support innovative approaches to sustainability challenges through a series of forums.

NASA Image of the Day

On March 13, 2008, the International Space Station passed across the field-of-view of Germany's remote sensing satellite, TerraSAR-X, at a distance of 195 kilometers, or 122 miles, and at a relative speed of 34,540 kilometers per hour, or more than 22,000 mph. In contrast to optical cameras, radar does not 'see' surfaces. Instead, it is much more aware of the edges and corners which bounce back the microwave signal it transmits. Smooth surfaces such as those on the station's solar generators or the radiator panels used to dissipate excess heat, unless directly facing the radar antenna, tend to deflect rather than reflect the radar beam, causing these features to appear on the radar image as dark areas. The radar image of the station therefore looks like a dense collection of bright spots from which the outlines of the space station can be clearly identified. The central element on the station, to which all the modules are docked, has a grid structure that presents a multiplicity of reflecting surfaces to the radar beam, making it readily identifiable. This image has a resolution of about one meter (about 39 inches). In other words, objects can be depicted as discrete units--that is, shown separately--provided that they are at least one meter apart. If they are closer together than that, they tend to merge into a single block on a radar image. Since this image was taken, the station has expanded and is more than 90 percent complete, including a full complement of solar arrays. Image Credit: DLR