Allan McDonald in 2016 holds a commemorative poster honoring the seven astronauts killed aboard the space shuttle Challenger.
Howard Berkes/NPR
hide caption
Allan McDonald, who directed the booster rocket project at NASA contractor Morton Thiokol, urged delaying the launch of the space shuttle before it exploded in 1986. He has died at age 83.
Allan McDonald in 2016 holds a commemorative poster honoring the seven astronauts killed aboard the space shuttle Challenger.
Howard Berkes/NPR
hide caption
Weeks before the 1980 census officially began, the Federation for American Immigration Reform launched its campaign to exclude unauthorized immigrants from population counts that, according to the Constitution, must include the "whole number of persons in each state."
Ernie Leyba/The Denver Post via Getty Images
hide caption
