Simplify the following text for a Grade 10 native English-speaking person.
Original: It has grown across nearby hills and along the Tennessee River , adding textile mills , then munitions factories , to become a major city , including NASA 's Marshall Space Flight Center and the United States Army Aviation and Missile Command nearby at the Redstone Arsenal .
Simplified: It has textile mills and also munitions factories . Also located in this city are NASA 's Marshall Space Flight Center and the United States Army Aviation and Missile Command at the Redstone Arsenal .