Personnel from NASA's Jet Propulsion Laboratory JPL oversee testing of the rotating radar antenna on NASA's International Space Station-RapidScat.

Personnel from NASA's Jet Propulsion Laboratory JPL in California oversee testing of the rotating radar antenna on NASA's International Space Station-RapidScat in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida. From left are JPL flight technician Kieran McKay and RapidScat project manager John Wirth.

Built at JPL, the radar scatterometer is the first scientific Earth-observing instrument designed to operate from the exterior of the space station. It will measure Earth's ocean surface wind speed and direction, providing data to be used in weather and marine forecasting. ISS-RapidScat will be delivered to the station on the SpaceX-4 commercial cargo resupply flight targeted for August 2014. For more information, visit http://www.jpl.nasa.gov/missions/iss-rapidscat. Photo credit: NASA/Daniel Casper