The ISS-RapidScat instrument was a speedy and cost-effective replacement for NASA's QuikScat Earth satellite, which monitored ocean winds to provide essential measurements used in weather predictions, including hurricane monitoring. So essential were QuikScat's measurements that when the satellite stopped collecting wind data in late 2009, NASA was challenged to quickly and cost-effectively conceive of a replacement. NASA's Jet Propulsion Laboratory and the agency's station program came up with a solution that uses the framework of the International Space Station and reuses hardware originally built to test parts of QuikScat to create an instrument for a fraction of the cost and time it would take to build and launch a new satellite.

The resulting ISS-RapidScat instrument was aboard the International Space Station and measured Earth's ocean surface wind speed and direction.

ISS-RapidScat used the unique vantage point of the space station to provide near-real-time monitoring of ocean winds, which are critical in determining regional weather patterns. Its measurements of wind speed and direction over the ocean surface have been used by agencies worldwide for weather and marine forecasting and tropical cyclone monitoring. Its location on the space station made it the first space-borne scatterometer that could observe how winds evolve throughout the course of a day.

"As a first-of-its-kind mission, ISS-RapidScat proved successful in providing researchers and forecasters with a low-cost eye on winds over remote areas of Earth's oceans," said Michael Freilich, director of NASA's Earth Science Division. "The data from ISS-RapidScat will help researchers contribute to an improved understanding of fundamental weather and climate processes, such as how tropical weather systems form and evolve."

The agencies that routinely used ISS-RapidScat's data for forecasting and monitoring operations include the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Navy, along with European and Indian weather agencies. It provided more complete coverage of wind patterns far out to sea that could build into dangerous storms. Even if these storms never reach land, they can bring devastating wave impacts to coastal areas far away.

"The unique coverage of ISS-RapidScat allowed us to see the rate of change or evolution in key wind features along mid-latitude storm tracks, which happen to intersect major shipping routes," said Paul Chang, Ocean Surface Winds Science team lead at NOAA's Center for Satellite Applications and Research. "ISS-RapidScat observations improved situational awareness of marine weather conditions, which aid optimal ship routing and hazard avoidance, and marine forecasts and warnings."

NASA's International Space Station Rapid Scatterometer (ISS-RapidScat) Earth science instrument has ended operations following a successful two-year mission aboard the space station. The mission launched Sept. 21, 2014, and had recently passed its original decommissioning date.

ISS-RapidScat was a partnership between JPL and the International Space Station Program Office at NASA's Johnson Space Center in Houston, with support from the Earth Science Division of NASA's Science Mission Directorate in Washington. Other mission partners include the agency's Kennedy Space Center in Florida and its Marshall Space Flight Center in Huntsville, Alabama; the European Space Agency; and SpaceX.

Mission Events

September 21, 2014: Successful Launch

August 19, 2016: A power distribution unit for the space station's Columbus module failed, resulting in a power loss to ISS-RapidScat.

October 17, 2016: Final attempt to restore to normal operations.

November 18, 2016: End of mission

Key Discoveries

During its mission, ISS-RapidScat also provided new insights into research questions such as how changing winds over the Pacific drove changes in sea surface temperature during the 2015-2016 El Niño event. Due to its unique ability to sample winds at different times of day, its data will be useful to scientists for years to come.