Virginia on April 27, 1959, to begin their astronaut training. Project Mercury On July 21, 1961, Grissom was pilot of the second Project Mercury flight, Mercury-Redstone 4. Grissom's spacecraft, which he named Liberty Bell 7, was launched from Cape Canaveral, Florida, a sub-orbital flight that lasted 15 minutes and 37 seconds. After splashdown in the Atlantic Ocean, the Liberty Bell 7s emergency explosive bolts unexpectedly fired, blowing off the hatch and causing water to flood into the spacecraft. Grissom quickly exited through the open hatch and into the ocean. While waiting for recovery helicopters from to pick him up, Grissom struggled to keep from drowning after his spacesuit began losing buoyancy due to an open air inlet. Grissom managed to stay afloat until he was pulled from the water by a helicopter and taken to the U.S. Navy ship. In the meantime another recovery helicopter tried to lift and retrieve the Liberty Bell 7, but the flooding spacecraft became too heavy, forcing the recovery crew to cut it loose, and it ultimately sank. When reporters at a news conference surrounded Grissom after his space flight to ask how he felt, Grissom replied, "Well, I was scared a good portion of the time; I guess that's a pretty good indication." Grissom stated he had done nothing to cause the hatch to blow, and no definitive explanation for the incident was found. Robert F. Thompson, director of Mercury operations, was dispatched to by Space Task Group Director Robert Gilruth and spoke with Grissom upon his arrival on the aircraft carrier. Grissom explained that he had gotten ahead in the mission timeline and had removed the detonator cap, and also pulled the safety pin. Once the pin was removed, the trigger was no longer held in place and could have inadvertently fired as a result of ocean wave action, bobbing as a result of helicopter rotor wash, or other activity. NASA officials concluded Grissom had not necessarily initiated the firing of the explosive hatch, which would have required pressing a plunger that required five pounds of force to depress. Hitting this metal trigger with the hand typically left a large bruise, but Grissom was found not to have any of the telltale hand bruising. While the debate continued about the premature detonation of Liberty Bell 7'''s hatch bolts, precautions were initiated for subsequent flights. Fellow Mercury astronaut Wally Schirra, at the end of