sentences:  Huntsville's economy was nearly crippled and growth almost came to a standstill in the 1970s following the closure of the Apollo program.However, the emergence of the Space Shuttle, the International Space Station, and a wide variety of advanced research in space sciences led to a resurgence in NASA-related activities that has continued into the 21st century.In addition, new Army organizations have emerged at Redstone Arsenal, particularly in the ever-expanding field of missile defense.