San Diego ? Walter M. “Wally” Schirra Jr., who as one of the original Mercury Seven astronauts combined the Right Stuff – textbook-perfect flying ability and steely nerves – with a pronounced rebellious streak, died Thursday at 84.

He was the only astronaut to fly in all three of NASA’s original manned spaceflight programs: Mercury, Gemini and Apollo. Although he never walked on the moon, Schirra laid some of the groundwork that made the lunar landings possible and won the space race for the U.S.

Schirra died of a heart attack at Scripps Green Hospital in La Jolla, said Ruth Chandler Varonfakis, a family friend and spokeswoman for the San Diego Aerospace Museum.

In 1962, the former Navy test pilot became the fifth American in space – behind Alan Shepard, Virgil “Gus” Grissom, John Glenn and Scott Carpenter – and the third American to orbit the Earth, circling the globe six times in a flight that lasted more than nine hours.

Schirra returned to space in 1965 as commander of Gemini 6. Some 185 miles above Earth, he guided his two-man capsule to within a few feet of Gemini 7 in the first rendezvous of two spacecraft in orbit.

On his third and final flight, aboard Apollo 7 in 1968, he helped set the stage for the landing of men on the moon during the summer of 1969.

An inveterate prankster, he could be grumpy and recalcitrant in space, most famously during his Apollo mission.

But “on Mercury, Gemini and Apollo, he flew all three and did not make a mistake,” said Christopher Kraft, who was Schirra’s Mercury and Gemini flight director and later head of NASA’s Johnson Space Center.

Schirra was named one of the Mercury Seven in 1959.

Schirra blasted off from Cape Canaveral on Oct. 3, 1962, aboard the Sigma 7 Mercury spacecraft. “I’m having a ball up here drifting,” Schirra said from space before making a perfect splashdown in the Pacific Ocean.

His Gemini mission represented a major step forward in the nation’s space race with the Soviet Union.

“Mostly it’s lousy out there,” Schirra said in 1981 on the occasion of the first space shuttle flight. “It’s a hostile environment, and it’s trying to kill you. The outside temperature goes from a minus 450 degrees to a plus 300 degrees. You sit in a flying Thermos bottle.”

Born in Hackensack, N.J., Schirra was practically born to fly. His father was a fighter pilot during World War I and later barnstormed at county fairs with Schirra’s mother, who sometimes stood on the wing of a biplane during flights.

Schirra took his first flight with his father at age 13 and already knew how to fly when he left home for the U.S. Naval Academy in Annapolis, Md.

Schirra flew 90 combat missions during the Korean War. He received the Distinguished Flying Cross and two Air Medals.

Survivors include his wife, Josephine, daughter Suzanne and son Walter Schirra III.