[Illustration: 82. Marine helicopter hovers over _Freedom 7_ after
the spacecraft carried the first American into space. Astronaut
Shepard dangles in body harness as he is hoisted to helicopter.]
On May 5, 1961, Alan B. Shepard, Jr., became the first American in
space. He flew this Mercury spacecraft, _Freedom 7_, through a
15-minute, 22-second sub-orbital, or ballistic, space flight.
A Redstone booster, burning liquid oxygen and hydrazine-base fuel,
lifted _Freedom 7_ from the launch pad at Cape Canaveral. The vehicle’s
single engine developed 35,380 kilograms (78,000 pounds) of thrust.
The structure of the Mercury is titanium, covered with steel and
beryllium shingles. The heat shield at the base of the spacecraft is of
beryllium.
The heat shield served as a “heat sink” by storing the heat created by
the spacecraft’s reentry into the earth’s atmosphere. The spacecraft
reached the ocean before the heat could penetrate the interior of the
craft. (Later flights used ablative heat shields, which protected the
spacecraft by vaporizing and burning away during reentry.)
_Freedom 7_ traveled at a maximum speed of 8335 kilometers (5180 miles)
per hour, going 485 kilometers (302 miles) downrange. The maximum
altitude was 187 kilometers (116 miles).
Prime contractor for Mercury was the McDonnell Aircraft Company.
The _Freedom 7_ is from the National Aeronautics and Space
Administration.
Diameter 2 m. (6 ft., 6 in.) max.
Length 2.8 m. (9 ft., 2 in.) at launch
Weight 1660 kg. (3650 lb.) at launch; 1100 kg. (2422
lb.) as exhibited