A mirror flaw in a new $1 billion series of weather satellites threatens to delay their launching and leave forecasters without vital pictures to track storms and hurricanes, a situation that federal officials say would constitute a national emergency.
The problem is a design flaw in mirrors meant to reflect light from telescopes of the next generation of Geostationary Operational Environmental Satellites, which are under construction and destined to orbit 22,300 miles above the Earth.
The craft are the main satellites the nation relies on for weather pictures. The nation has forecasting equipment in aircraft, radar units and other satellites, but only this type of satellite gives a comprehensive overview of the weather situation at any instant.
A single satellite of this type is now in orbit, and the danger is that it could fail before a replacement is launched.
When the mirrors in the next generation of advanced satellites are heated, as sunlight would do in outer space, they warp. Although the program began in 1984, the design flaw was discovered only in the last few weeks, federal officials said in interviews Tuesday.
Five satellites are being built by Ford Aerospace, with construction supervised by NASA. The trouble is likely to give new ammunition to critics of the space agency, which is already reeling from technically unrelated problems with its $25 billion space shuttle fleet and a defective mirror on its $1.5 billion Hubble Space Telescope.
Each satellite has two such mobile mirrors, one for a large sensor to measure temperatures in the Earth`s atmosphere and one for a picture-taking camera.
In Washington, James R. Greaves, NASA`s program manager for meteorological satellites, said delivery of finished sensors might be delayed two to six months if mirrors have to be repaired, and more than a year if new mirrors have to be manufactured. ``We`re hopeful the thing can be modified,`` he said.
The ``scary aspect`` of the situation, Greaves added, was that the nation was down to one operational advanced satellite.
``If that fails, weather people are going to be standing in front of blank screens,`` he said. ``That`s where the hurt is going to be.``