Scott Carpenter

Born: May 1, 1925; Died: October 10, 2013.

Scott Carpenter, who has died aged 88, was an astronaut who made three orbits of the Earth in 1962 and led the way for the first landing on the Moon seven years later. He was the second American to orbit the Earth but as an astronaut and an aquanaut, was also the first man to explore both the depths of the ocean and the heights of space.

The first American to orbit the earth was John Glenn in February 1962 and it was Carpenter who gave him the famous send-off "God speed, John Glenn". Three months later, Carpenter followed Glenn, orbiting the Earth three times. He lost contact with Nasa during the off-target landing but was found safely floating in his life raft 288 miles away.

A former Navy pilot, Carpenter remembered the launch into space on the morning of May 24, 1962 as particularly nerve-racking. "You're looking out at a totally black sky, seeing an altimeter reading of 90,000 feet and realise you are going straight up," he said. "And the thought crossed my mind: 'What am I doing?'" In the end, though, the momentary fear was worth it. "The view of Mother Earth and the weightlessness is an addictive combination of senses."

For the veteran Navy officer, flying in space or diving to the ocean floor was more than a calling. In 1959, soon after being chosen as one of Nasa's pioneering seven astronauts, Carpenter wrote about his hopes: "This is something I would willingly give my life for."

He was born in Boulder, Colorado, and brought up by his maternal grandfather after his parents divorced. On leaving school, he joined the US Navy before studying aeronautical engineering at the University of Colorado. After returning to the military, he trained as a Navy test pilot and in 1959 was selected as a possible candidate for manned space flights. There were 110 servicemen candidates chosen; Carpenter was in the last seven.

He was finally selected as the backup pilot for John Glenn in 1961 and the following year gave Glenn his famous send-off. It was a spur of the moment phrase, Carpenter later said. "In those days, speed was magic because that's all that was required ... and nobody had gone that fast," he explained. "If you can get that speed, you're home free, and it just occurred to me at the time that I hope you get your speed. Because once that happens, the flight's a success."

Three months later, Carpenter was launched into space from Cape Canaveral, Florida, and completed three orbits around Earth in his space capsule, the Aurora 7.

His 4 hr 39min 32sec of weightlessness were the nicest thing that ever happened to him, he said. "The zero-G sensation and the visual sensation of spaceflight are transcending experiences," he said, "and I wish everybody could have them."

Things started to go wrong on re-entry. He was low on fuel and a key instrument that tells the pilot which way the capsule is pointing malfunctioned, forcing Carpenter to manually take over control of the landing. Nasa's Mission Control then announced that he would overshoot his landing zone by more than 200 miles, and worse, they had lost contact with him. Talking to a suddenly solemn nation, CBS newsman Walter Cronkite said: "We may have ... lost an astronaut."

However, always cool under pressure, Carpenter oriented himself by simply peering out the space capsule's window. The Navy found him in the Caribbean, floating in his life raft with his feet propped up.

His perceived nonchalance did not sit well some with Nasa officials, particularly flight director Chris Kraft. The two feuded about it from then on.

Kraft accused Carpenter of being distracted and behind schedule, as well as making poor decisions. He blamed Carpenter for low fuel.

On his website, Carpenter acknowledged that he didn't shut off a switch at the right time, doubling fuel loss. Still, Carpenter in his 2003 memoir said: "I think the data shows that the machine failed."

Carpenter never went back in space, but his explorations continued. In 1965, he spent 30 days under the ocean off the coast of California as part of the Navy's SeaLab II programme. "I wanted, number one, to learn about it (the ocean), but number two, I wanted to get rid of what was an unreasoned fear of the deep water," Carpenter said.

After another stint at Nasa in the mid-1960s, helping develop the Apollo lunar lander, Carpenter returned to the SeaLab programme as director of aquanaut operations for SeaLab III.

He retired from the Navy in 1969, founded his company Sea Sciences, and dived in most of the world's oceans, including under the ice in the Arctic. Life was an adventure for Carpenter and he said it should be for others: "Every child has got to seek his own destiny. All I can say is that I have had a great time seeking my own."

He is survived by his fourth wife, Patty, and four sons and two daughters. Two other sons pre-deceased him.