Chal ‧ len ‧ ger /ˈtʃæləndʒəʳ, ˈtʃælɪndʒəʳ/ BrE AmE
a US ↑ space ↑ shuttle which exploded after TAKEOFF on one of its flights in 1986, killing all seven people inside. The terrible accident was watched on television by many people and shocked the whole of the US.