Colorado Teamwork Leads to Success of Cloudsat, a Satellite Weather Radar Scheduled to Launch April 21

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Colorado scientists from Colorado State University and Boulder-based Ball Aerospace and Technologies Corp. collaborated to help build the $217 million CloudSat satellite project, largely funded by NASA, that will improve weather and climate prediction and develop critical new space technologies.

CloudSat, a NASA Earth System Science Pathfinder Mission, is expected to launch into orbit on April 21 at Vandenberg Air Force Base, Calif. The world’s most sensitive cloud radar is designed to measure properties of clouds essential to understanding Earth’s weather and climate processes.

"CloudSat observations will allow us to peer inside clouds, like a CT scan, to observe for the first time the important processes that affect our weather and climate on the large, global scale," said Graeme Stephens of Colorado State’s Department of Atmospheric Science who has worked on CloudSat for 12 years.     

Stephens, Colorado State’s most recently named University Distinguished Professor, is CloudSat’s principal investigator. However, CloudSat has many partners, including NASA’s Jet Propulsion Laboratory, Canadian Space Agency, U.S. Air Force, U.S. Department of Energy and Ball Aerospace.

This is the second NASA mission that has involved Ball and Colorado State atmospheric scientists in Colorado. In 1984, Colorado State’s Earth Radiation Budget Satellite, built by Ball, was the first NASA science satellite to be launched from the Challenger space shuttle. Colorado State Professor Tom Vonder Haar served as the project scientist on that satellite during its conceptual development stages.

"This project wouldn’t happen without Ball, which designed a launch vehicle critical to the success of this mission," Stephens said of CloudSat. "From day one, they have been an outstanding partner in this great endeavor."

"We’re proud that our adaptable Earth orbiting platforms, in this case the Ball Commercial Platform 2000, have been successful for so many Earth science missions," said Randy Coffey, Ball Aerospace program manager for CloudSat. "The joint collaboration with CSU makes it all the more gratifying."

The vertical profiles of global cloud properties provided by CloudSat will fill a critical gap in understanding how clouds affect climate and uncover new knowledge about clouds and precipitation and the connection of clouds to the large-scale motions of the atmosphere. Clouds are an important stage in Earth’s great water cycle, converting the salty water of the oceans to the fresh water over land needed to sustain life. Without clouds there would be no rains, no freshwater and no human life. Despite this importance, scientists’ ability to forecast clouds and rainfall from clouds is poor and a weak link in all weather and climate modeling, Stephens said.

"Clouds are a very important part of Earth’s weather and climate, and the lack of understanding of cloud feedback is widely acknowledged in the scientific community to be a major obstacle confronting credible prediction of climate change," said co-principal investigator Deborah Vane of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "Despite the fundamental role of clouds in climate and weather, there is much that we do not know. The CloudSat mission aims to provide observations necessary to greatly advance understanding of these climate issues."

CloudSat will help researchers in numerous scientific disciplines to:

– Better understand climate processes: CloudSat data will support new, detailed investigations of how clouds determine the Earth’s energy balance.

– Improve weather forecasts: CloudSat will improve weather prediction models by measuring cloud properties from the top of the atmosphere to the surface of the Earth, filling a gap in existing and planned space observational systems.

– Enhance natural hazard mitigation: CloudSat will penetrate into and through thick cloud systems, providing new information to increase the accuracy of severe storm, hurricane and flood warnings.

– Improve water resource management: CloudSat will link climate conditions to hydrological processes that affect occurrences of drought, incidences of severe weather and availability of water.

– Develop advanced technology: the CloudSat mission is spurring innovative technology including high-power radar sources, methods of radar signal transmission within spacecraft and integrated geophysical retrieval algorithms.

A unique component of the mission design is that the CloudSat spacecraft will fly in orbital formation as part of a constellation of satellites, including NASA’s Aqua and Aura satellites, the French Space Agency (CNES) PARASOL satellite and the NASA-CNES CALIPSO satellite. This will be the first time that five research satellites will fly together in formation.

CloudSat’s radar measurements will overlap those of the other satellites in the constellation. The precision of this overlap creates a unique multi-satellite observing system for studying the atmospheric processes essential to the Earth’s hydrological cycle and weather systems and will provide unsurpassed information about the role of clouds in weather and climate.

The collaborative mission draws on the expertise of industries, universities and laboratories in the United States, Canada, Japan and Europe. The CloudSat satellite will use the first-ever space-borne millimeter wavelength cloud profiling radar, developed for NASA by JPL in partnership with the Canadian Space Agency. This highly advanced radar has the ability to measure both the altitude and the physical properties of clouds. Existing space-based systems can observe only the uppermost layer of clouds and cannot reliably detect the presence of multiple cloud layers or determine the cloud water and ice content.

The mission is managed and implemented by JPL for NASA’s Earth Explorers Program Office at the Goddard Space Flight Center. Ball Aerospace built the spacecraft that will be launched from Vandenberg on the same Delta rocket with the CALIPSO spacecraft.

The U.S. Air Force will operate the CloudSat spacecraft in orbit and will deliver the raw data to the Cooperative Institute for Research in the Atmosphere, or CIRA, located at Colorado State. CIRA will process all CloudSat data and deliver data products to the scientific community. CloudSat data also will be distributed to civilian and military weather forecast agencies.

The U.S. Department of Energy will provide independent verification of the radar performance through its Atmospheric Radiation Measurement Program. Scientists from the United States, Germany, France, Canada and Japan are contributing their facilities and expertise to develop science data products, analyze data and complement the DOE on-orbit verification efforts.

The CloudSat mission is designed for a two-year lifetime to observe more than one seasonal cycle. However, there is no anticipated technical reason why the mission could not last longer, as the radar is expected to operate for a minimum of three years.