On July 21, 1961, NASA astronaut Gus Grissom completed the second successful human spaceflight mission for the United States of America.

His suborbital flight in the Liberty Bell 7 capsule lasted 15 minutes and 30 seconds and reached an altitude of 103 nautical miles. Everything went according to plan until just after Grissom splashed down in the Atlantic Ocean. While Grissom was waiting on the recovery crew to come get him, the hatch cover on Liberty Bell 7 unexpectedly blew open and water started pouring into the capsule. Grissom barely made it out alive, but Liberty Bell 7 sank into the ocean.