For Release: March. 16, 1995

Steve Roy
Marshall Space Flight Center, Ala.
(205) 544-6535

RELEASE NO: N95-21

DATE SET FOR FLIGHT OF GLOBAL LIGHTNING OBSERVER

The world’s first space-based sensor capable of detecting atmospheric lightning events with high location accuracy and sensitivity is scheduled for launch on Saturday, March 18, 1995. Built by NASA’s Marshall Space Flight Center in Huntsville, Ala., the Optical Transient Detector will be carried into orbit 440 miles (710 kilometers) above the Earth by a Pegasus rocket furnished by Orbital Science Corporation.

The Optical Transient Detector is a compact optical instrument which detects momentary changes in light intensity in its field of view, day or night. This momentary change is an indication of the occurrence of lightning. It will detect, locate and measure the intensity of lightning for scientific investigation of the distribution and variability of total lightning over the Earth and to increase our understanding of the Earth's Atmosphere system. Lightning is closely coupled to storm convection dynamics, and can be correlated to the global rates, amounts and distribution of convective precipitation. The Optical Transient Detector will contribute to studies of the Earth’s water cycle, sea-surface temperature variations, electrical coupling of thunderstorms with the ionosphere and magnetosphere, and modeling of the global distribution of electrical fields and currents in the Earth's atmosphere. In addition, it will begin the development of a global lightning climatological database for use in NASA’s Mission to Planet Earth Global Climate Change Program.

Data from the Optical Transient Detector will be analyzed by scientists located at Marshall Center’s Global Hydrology and Climate Center. Data products will be developed and produced in the climate center's Optical Transient Detector Science Computer Facility and archived and distributed in the Earth Observing Systems Data Information System for the hydrologic cycle.

The Optical Transient Detector is one of three payloads on the Pegasus rocket scheduled be launched from an Orbital Systems Corporation L-1011 aircraft operating out of Vandenberg Air Force Base, Calif. The Optical Detector is mounted on a small satellite system called MicroLab-1. In orbit, with the Optical Detector’s relatively wide 100-degree field of view, it will be able to survey virtually all areas of the globe, where lightning occurs.

Following the launch operations at Vandenberg Air Force Base, a written status report on the Optical Transient Detector operations will be distributed by fax. Subsequent status reports on the science operations of the project will be distributed periodically or may be obtained by calling Steve Roy at (205) 544-6535.