From 1981 to 2011, the United States focused on reusable space shuttles. Many successful shuttle launches completed scientific and military space missions during this time. However, the space shuttle program was marred by two major tragedies. On January 28, 1986, the space shuttle Challenger exploded 73 seconds after liftoff. All seven people on board died, including a teacher named Christa McAuliffe. McAuliffe would have been the first civilian in space. The second tragedy occurred on February 1, 2003. The shuttle Columbia was returning from a 16-day research mission when it disintegrated while reentering Earth’s atmosphere. The seven-person crew died. After each of the disasters, space shuttle operations were suspended for more than two years. Based on the text, which of the following statements is true?

A
Challenger exploded at the beginning of its mission, and Columbia exploded at the end of its mission.

B
The Challenger disaster took place in 2003, and the Columbia disaster took place in 1986.

C
Both Challenger and Columbia were carrying teachers on board.

D
Both the Challenger and the Columbia disasters had survivors.