Mercury-Redstone 4

Mercury-Redstone 4 was the second United Stateshuman spaceflight, on July 21, 1961. The suborbitalProject Mercury flight was launched with a Mercury-Redstone Launch Vehicle, MRLV-8. The spacecraft, Mercury capsule #11, was nicknamed Liberty Bell 7. It was piloted by astronautVirgil "Gus" Grissom.

The spaceflight lasted 15 minutes 30 seconds, reached an altitude of more than 102.8 nautical miles (190.4 km), and flew 262.5 nautical miles (486.2 km) downrange, landing in the Atlantic Ocean. The flight went as expected until just after splashdown, when the hatch cover, designed to release explosively in the event of an emergency, accidentally blew. Grissom was at risk of drowning, but was recovered safely via a U.S. Navyhelicopter. The spacecraft sank into the Atlantic and was not recovered until 1999.