This week in 1991, STS-48 launched aboard space shuttle Discovery to deploy the Upper Atmosphere Research Satellite — the first multi-instrumented satellite to observe numerous chemical components of Earth’s atmosphere for better understanding of photochemistry. NASA’s fleet of satellites, its airborne missions and researchers address some of the critical challenges facing our planet today and in the future — climate change, sea level rise, freshwater resources and extreme weather events. The NASA History Program is responsible for generating, disseminating and preserving NASA’s remarkable history and providing a comprehensive understanding of the institutional, cultural, social, political, economic, technological and scientific aspects of NASA’s activities in aeronautics and space. For more pictures like this one and to connect to NASA’s history, visit the History Program’s webpage.