Carpenter was the second American to orbit the Earth, and the fourth American in space. His daughter, Kristen Stoever, confirms he passed away at 5:30am in Vail, Colorado.
His wife, Patty Barrett, says Carpenter died of complications from a stroke in a Denver hospice.
As an astronaut and aquanaut who lived underwater for the U.S. Navy, Carpenter was the first man to explore both the depths of the ocean and the heights of space.
Carpenter gave the famous send-off - "Godspeed, John Glenn" - when Glenn became the first American in orbit in February 1962.
Three months later, Carpenter orbited 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.
Carpenter's death leaves John Glenn as the last living member of the Mercury Seven.
The Associated Press contributed to this report
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