The disintegration of the Space Shuttle Challenger on January 28 , 1986 , proved a pivotal moment in Reagan 's presidency . All seven astronauts aboard were killed . On the night of the disaster , Reagan delivered a speech , written by Peggy Noonan , in which he said : In 1988 , near the end of the Iran – Iraq War , the U.S. Navy guided missile cruiser accidentally shot down Iran Air Flight 655 killing 290 civilian passengers . The incident further worsened already tense Iran – United States relations
Iran Air Flight 655
Iran Air Flight 655
Ronald Reagan