Freedom 7 — Alan Shepard, first American in space

Alan Shepard lay on his back atop a Redstone rocket for more than four hours on the morning of 5 May 1961, through hold after hold, while an estimated 45 million Americans watched on live television. The Soviet Union had already flown Gagarin around the entire planet three weeks earlier, and the pressure on this fifteen-minute mission was continental. The bladder question got settled the undignified way, inside the suit. When yet another hold was called for rising pressure in the booster's liquid oxygen tank, Shepard finally snapped at the control room with the most famous demand in NASA history.

At 9:34 a.m. Eastern time the Redstone lifted off from Launch Complex 5 at Cape Canaveral. The flight was a fifteen-minute arc: Freedom 7 reached 116.5 statute miles of altitude, touched 5,134 miles per hour, and gave Shepard about five minutes of weightlessness before slamming him with roughly 11 g on reentry. Unlike Gagarin, who rode his Vostok largely as a passenger, Shepard took the controls, testing pitch, yaw, and roll by hand. He became the first human being to actually pilot a spacecraft in space.

Splashdown came 303 miles downrange in the Atlantic, where a Marine helicopter hauled capsule and astronaut to the carrier USS Lake Champlain. The whole flight, liftoff to splashdown, lasted 15 minutes and 28 seconds. It was enough. Twenty days later, President Kennedy stood before Congress and committed the United States to landing a man on the Moon before the decade was out, a goal staked on a quarter hour of suborbital flight time.

The capsule's name carried a quiet code: the 7 was simply McDonnell's production number for the capsule, and the Mercury Seven astronauts adopted it as a badge of unity on every flight that followed. Shepard himself was grounded by an inner-ear disease for most of the decade, then fought his way back to flight status and walked on the Moon in 1971 as commander of Apollo 14, the only Mercury astronaut ever to do so.