WEATHER satellites teach important lessons. It's easy to become dependent on high technology. Then, having become so dependent, it's dangerous to take that technology for granted.One such technology may let us down. The United States geostationary satellite (GOES) system, which gives North Americans a bird's-eye view of weather, is just an electronic "heartbeat" away from blackout. Normally, two satellites monitor weather from Eastern North America out over the Atlantic Ocean and from western regions out over the Pacific. However, the National Oceanic and Atmospheric Administration (NOAA) now has only GOES-7 - the last unit in the present GOES series - to work with. The follow-on GOES-Next series of advanced satellites remains grounded. Technical problems have delayed its launch, originally expected in 1989, until December 1992 or later. There could be a complete gap if GOES-7 fails before a replacement arrives on orbit. In any event, the satellite will run low on maneuvering fuel next year. Congressional studies, including hearings and a recent report by the General Accounting Office, have detailed serious mismanagement by the National Aeronautics and Space Administration and its contractors who are developing the GOES-Next system for NOAA. NASA administrator Richard Truly admits the faults and promises his agency will do better. A major error was made in trying to save time and money by forgoing "proof-of-concept" engineering tests of the GOES-Next design. These would likely have shown that NASA's timetable to produce an operational GOES-Next satellite was unrealistic. Lesson 1: Don't cut corners in developing sophisticated technology. Lesson 2: It is fundamentally bad management of a crucial operational system to allow its continued use to depend on the timely arrival of untested technology. NOAA should not have shut down the old GOES production line before GOES-Next was ready. Officials in both NOAA and NASA acknowledge this point. Lesson 3: In this high-technology world, no nation is an island. Other Western Hemisphere countries depend on GOES, and the United States benefits from other nations' satellite systems. All of these systems share data to track weather globally. Also, a European satellite has been repositioned to give broader Atlantic Ocean coverage enabling NOAA to position GOES-7 to see more of western North America. Perhaps it is time to develop a fully integrated global weather satellite network in which national systems would back up each other. This would mean designing national systems to mesh together smoothly. It also would mean sharing technology so that all national systems worked to the same high standards. In a crowded world where common safety from weather hazards now depends partly on satellite monitoring, such sharing has become a necessity.