November 14, 1997
Successful measurements in this key region of the atmosphere could lead to improved weather forecasting and better understanding of climate-related events such as El Nino.
Based on technology tested aboard research aircraft, the Space-Readiness Coherent Lidar Experiment (Sparcle) will detect the frequency shift of an eye-safe laser pulse as it reflects off dust and aerosol particles as they move with the winds. The resulting measurements should give researchers precise information about the speed, direction and vertical profile of tropospheric winds.
Due to launch in 2001 at an estimated cost of $15 million, Sparcle will be managed by NASA's Marshall Space Flight Center, Huntsville, AL, as the second Earth-orbiting mission in the agency's New Millennium Program. If successful, a more robust system based on Sparcle could be a candidate for launch aboard a free-flying satellite within the following few years.
"After several years of critical basic research, the technology to accomplish these measurements has only just reached the point that we could consider demonstrating this promising concept on a Space Shuttle flight," said William Townsend, Acting Associate Administrator for NASA's Office of Mission to Planet Earth. "If this experiment is successful, we expect that the operational deployment of such a capability would produce substantial improvements in the accuracy of weather forecasts, and new insights into the causes and effects of climate change."
Global wind data from an orbiting system has been identified as the number one item on a "wish list" of measurements compiled by the international operational meteorology community, according to Dave Emmitt, Sparcle mission scientist and a research assistant professor at the University of Virginia, Charlottesville.
"This is an exciting time for a number of people who have, until now, had only paper studies to convince their colleagues that winds could be measured accurately from space with lasers," Emmitt added. "The global community of atmospheric researchers, weather forecasters, and weather-sensitive industries will be watching as NASA explores this new frontier of space-based laser sensing of the Earth's winds."
The experiment will be carried to orbit and back in two Space Shuttle Hitchhiker canisters that weigh approximately 200 pounds (320 kilograms) each. Researchers hope to obtain approximately 50 hours of wind data.
Other partners in the development of Sparcle include NASA's Goddard Space Flight Center, Greenbelt, MD; Langley Research Center, Hampton, VA; the Jet Propulsion Laboratory, Pasadena, CA; the University of Alabama at Huntsville, and several private companies.
A mission called Earth Orbiting-1, scheduled for launch in May 1999, will demonstrate an advanced land imager system with a multispectral capability that can replace the current measurement approach used by such systems as the Landsat satellites. It also will demonstrate a hyperspectral capability that can break up the radiation reflected by Earth's land surfaces into hundreds of distinct bands, as compared to the half-dozen bands common on today's remote-sensing spacecraft.
The primary goal of the New Millennium program is to identify, develop, validate in flight key instrument and spacecraft technologies that can lower the cost and increase the performance of science missions in the 21st century. The overall program is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science and Office of Mission to Planet Earth, Washington, DC.
NASA's Mission to Planet Earth enterprise is a long-term research program designed to study the Earth's land, oceans, air, ice and life as a total system.