On May 25, 1961 President Kennedy announced: 的 believe this nation should commit
itself to achieving the goal, before this decade is out, of landing a man on the Moon and
returning him safely to Earth. In pursuit of this goal, it was considered necessary to
conduct several unmanned test flights and supporting programs, including the Mercury,
Gemini, Ranger, Surveyor and Lunar Orbiter.
The Mercury program aimed at meeting the Soviet challenge and putting American
astronauts into orbit around the earth. The Mecury-Redstone launched the first U.S.
astronaut into space on May 5, 1961. Alan Shepard spent about 15 minutes in space
during a sub-orbital mission aboard the Mercury capsule 擢reedom 7. Gus Grissom
followed in his Mercury craft, the 鏑iberty Bell, on an identical mission shortly after.
Since the Redstone was only 登ne-staged, it did not have the propulsive power to put
two astronauts in space on the same mission. The Mecury-Atlas launch vehicle was a
登ne-and-a-half stage vehicle which used an ultra-light-weight structure to reduce the
lift-off weight of the rocket. Even with this development, it can barely make it into a
low-altitude Earth orbit. This modified vehicle launched John Glenn in his 擢riendship 7
capsule into three Earth orbits on February 20, 1962. He was followed by astronauts
Scott Carpenter, Walter Schirra, and Gordon Cooper in Mercury missions of somewhat
longer duration.
The Gemini program was the next major space activity. Its two-stage design
permitted two men to ride into space together so that they could conduct 兎xtra vehicular
activities, or EVA痴. On June 3, 1965, Ed White took a daring step out of the Gemini 4
capsule into space. There he somersaulted, floated lazily on his back, pirouetted, and
stood grinning like a kid on Gemini痴 titanium hull for 21 minutes. The Gemini capsule
was also designed to use fuel cells, which is one of the first technologies required for lunar
The Ranger series was the first American unmanned spacecraft to land on the
Moon. The idea was that the spacecraft were going to fly straight into the Moon and
would be destroyed on impact, so the pictures had to be sent back as quickly as they were
taken. The first few Ranger shots (August, 1961 - October, 1962) failed for a variety of
reasons, not all connected with the spacecraft itself. However, Ranger 4 did reach the
Moon on April 26, 1962, being the first American spacecraft to do so.
The Surveyor series was very successful in obtaining information about the lunar
surface. Surveyor 1 lifted from Cape Kennedy on May 30, 1966 with textbook precision.
It was the first flight of a space probe, and the first operational use of the liquid-hydrogen
fueled booster. It eased itself on the Moon using gentle blasts from three small
liquid-fueled vernier rockets, under the control of a computer which was kept informed of
height and velocity by the onboard radar. The Surveyor carried solar cells, generating
electricity from sunlight, so it was able to transmit thousands of superb photographs
before the Sun set and the long lunar night began. Even then, it survived the low
temperatures and revived at dawn, giving the experimenters an extra bonus.
On August 10, 1966, the United States launched the Lunar Orbiter 1. Orbiter痴
mission was primarily photographic. Orbiter 1 functioned superbly, producing the first
high-definition pictures of the lunar Farside. Later, Orbiters did even better, producing a
portfolio of lunar photographs. These photographs were of great importance, because the
Rangers and Surveyors had begun to give the impression that the Moon was a somewhat
dull, flat, and uninteresting place. But now the image was beginning to emerge of a world
with landscapes as dramatic as any on Earth.
The next step in reaching President Kennedy痴 goal was the Apollo program,
which required an entirely new launch vehicle, the Saturn. On January 27, 1967, during a
ground test of the Apollo spacecraft, fire broke out in the three-man command module.
Because of the pressurized pure-oxygen atmosphere inside the spacecraft, a flash fire
engulfed and killed the three astronauts: Grissom, White, and Commander Chaffee. As a
result of this tragedy, the Apollo program was delayed more than a year while a major
review of vehicle design and materials was accomplished. In October 1968, the first
manned Apollo flight was launched by a Saturn IB booster. Astronauts Shirra,
Cunningham, and Eisele circled the Earth for 163 orbits, checking spacecraft performance,
photographing the Earth, and transmitting television pictures. In December 1968, Apollo
8, a landmark flight, carrying astronauts Borman, Lovell, and Andrews, circled the moon
ten times. The Apollo 9 flight