Gemini/Titan-II launch vehicle lift-off at Cape Kennedy,
Florida in a test flight.
In May 1961, soon after the
first Project Mercury flight, President John F. Kennedy
declared that the United States would put an astronaut on
the Moon before the end of the decade. The Space Race with
the Soviets had just become a race to the Moon, and the
United States was determined to win it.
At the conclusion of
Project Mercury, however, the United States had amassed only
two days and six hours in space. It soon became evident that
an intermediate step was needed before an attempt to go to
the Moon could be made. Thus, Project Gemini was conceived.
On December 7, 1961, the National Aeronautics and Space
Administration (NASA) announced a plan to extend the piloted
spaceflight program by developing a two-person spacecraft.
On January 3, 1962, NASA officially named the program
Gemini, for the third constellation of the Zodiac and its
twin stars, Castor and Pollux.
Gemini was planned to
perfect the techniques needed for a lunar mission. Its
primary purpose was to demonstrate space rendezvous and
docking techniques that would be used during the later
Apollo flights to the Moon, when the lunar lander would
separate from the command module in orbit around the Moon,
then meet up with it again after the astronauts left the
lunar surface. Gemini also sought to extend astronauts'
stays in space to two weeks, longer than even the Apollo
missions would require.
During Gemini, ten piloted
missions lifted off from Cape Canaveral, Florida, in less
than 20 months. The Manned Spacecraft Centre (renamed the
Johnson Space Centre in 1973) near Houston, Texas, took over
the role of Mission Control, and ground operations became
smooth and efficient, due in part to the extremely short
launch windows. For instance, Gemini XI had only a
two-second “window” when it could launch, due to the need to
rendezvous with a target already in orbit. Meanwhile, the
program introduced 16 new astronauts to the space
The Gemini spacecraft
(originally called Mercury Mark II) was an improvement on
the Mercury capsule. It was 19 feet long (5.8 meters), 10
feet (three meters) in diameter, and weighed about 8,400
pounds (3,810 kilograms)—twice the weight of Mercury. But it
had only 50 percent more cabin space for twice as many
people, and was extremely cramped. Ejection seats replaced
Mercury's escape rocket, and more storage space was added
for the longer Gemini flights. The long-duration missions
also used fuel cells instead of batteries for generating
electrical power. An adapter module fitted to the rear of
the capsule (and jettisoned before re-entry) carried on-board
oxygen, fuel, and other consumable supplies. Engineering
changes, such as systems that could be removed and replaced
easily, simplified maintenance. Since spacewalks were an
essential part of these missions, the spacesuit became a
crucial piece of equipment, providing the only protection
for the astronaut from the deadly environment of space.
The Titan II rocket, more
powerful than the rockets used for the Mercury missions,
placed the larger spacecraft into orbit. The targets for
rendezvous operations were un-crewed Agena upper stages,
which were launched ahead of the Gemini.
Unlike Mercury, which had
been able to change only its orientation while in flight,
Gemini needed to the capability to move forward, backward
and sideways in its orbital path, and even change orbits to
rendezvous with other spacecraft. The complexity of
rendezvous demanded two people on board, and more piloting
than had been possible with Mercury. It also required the
first onboard computers to calculate complicated rendezvous
The first two Gemini
flights were unpiloted. Gemini 1 made 64 orbits and
confirmed that the Titan II launch vehicle and the
spacecraft were compatible. Gemini 2 tested all the
spacecraft systems in a suborbital flight.
and Young inside their Gemini spacecraft before launch.
The first piloted flight
was Gemini III—nicknamed Molly Brown. Only the Gemini III
was nicknamed; pilot Virgil Grissom named it after the
Broadway musical The Unsinkable Molly Brown. His spacecraft
during Project Mercury had sunk at the end of his flight.
The Molly Brown, piloted by Grissom and John Young, made
three orbits in its almost five-hour flight on March 23,
1965, in which the astronauts were able to alter their oval
orbit to a more circular one and to execute other orbital
changes using the thrusters. Their attempt at a precision
landing, however, was unsuccessful, as were several future
flights, and the spacecraft splashed down more than 50 miles
(80 kilometres) from its target.
Gemini IV, a four-day
flight piloted by James McDivvitt and Edward White, was
launched on June 3, 1965. The highlight of this flight was
the first extravehicular activity (EVA) by an American;
White's 22-minute "spacewalk." Using a handheld
unit, he “swam through space” while attached to his lifeline
tether, moving at nearly 18,000 miles per hour (29,000
kilometres per hour). The mission also attempted to
rendezvous with the second stage of the Titan launch vehicle
but was unsuccessful. They later learned that a spacecraft
trying to catch up with another needed to drop to a lower,
faster orbit first before rising again.
The Gemini V mission,
piloted by L. Gordon Cooper, Jr. and Charles Conrad, Jr.,
lasted almost eight days and completed 120 orbits in August
1965. It demonstrated the first use of fuel cells for
electrical power, although they did not supply enough power
and some experiments and a planned rendezvous had to be
This photograph of
the Gemini 7 spacecraft was taken from the hatch window
of the Gemini 6 spacecraft during rendezvous and station
keeping manoeuvres at an altitude
of approximately 160 miles on December 15, 1965.
The Gemini VI flight,
scheduled for launch on October 25, 1965, was scrubbed when
the Agena target spacecraft with which the crew had planned
to rendezvous and dock exploded during its launch.
Consequently, Gemini VII, piloted by Frank Borman and James
Lovell, Jr., was launched first, on December 4, 1965, to
become the rendezvous target for Gemini VI. When Gemini VI
was launched on December 15, piloted by Walter Schirra, Jr.
and Thomas Stafford, the two spacecraft rendezvoused and
flew in formation for five hours. Gemini VII remained aloft
for 14 days to study the effects of long-duration flight.
The 330 hours in space had no long-term harmful effects on
the crew, but the flight turned into somewhat of an
endurance test for the two pilots, confined in their hot,
Astronaut Edward H. White II, pilot for the Gemini 4
spaceflight, floats in zero gravity of space.
The extravehicular activity was performed during the third
revolution of the Gemini 4 spacecraft.
White is attached to the spacecraft by a 25-ft. umbilical
line and a 23-ft. tether line,
both wrapped in gold tape to form one cord.
In his right hand White carries a and-Held Self-Maneuvering
Unit (HHSMU). The visor of his helmet is gold plated to protect him from
the unfiltered rays of the sun.
Gemini VIII, launched on
March 16, 1966, was piloted by Neil A. Armstrong and David
R. Scott, who carried out the first docking and undocking
with another spacecraft. The flight lasted only 10 hours, 41
minutes because of a malfunctioning thruster that caused the
spacecraft to spin uncontrollably at a rate of about one
revolution per second. This caused the crew to execute the
first emergency landing of a piloted U.S. spaceflight
Thomas P. Stafford and
Eugene A. Cernan became the first backup crew to fly a
spaceflight mission after the original crew of Elliott See
and Charles Bassett died in a plane crash four months before
the flight. Gemini IX was launched on June 3, 1966, and flew
almost four days. A docking had been scheduled, but the crew
discovered when they rendezvoused with the target that its
protective shroud was still attached, making docking
impossible. Plans to test an Astronaut Manoeuvring Unit as
part of a spacewalk was also cancelled when Cernan's
faceplate became fogged, limiting his visibility.
Gemini X, a three-day
flight launched on July 18, 1966 with John Young and Michael
Collins as pilots, demonstrated the first double docking,
first docking with an Agena target vehicle, and later with
another Agena still floating from an earlier mission.
Collins “walked” in space for 39 minutes at the end of a
tether. This mission accomplished all of Gemini's
objectives: rendezvous, docking, manoeuvring, and a
spacewalk during which work was performed.
Areas of Sudan and
Egypt as seen from Gemini 11 spacecraft.
On Gemini XI, launched on
September 12, 1966, the crew matched orbits with an Agena
test vehicle only 85 minutes after launch and docked several
times. This three-day flight, piloted by Charles Conrad, Jr.
and Richard Gordon, Jr., reached the highest Earth orbit to
date—739.2 miles (1,189.3 kilometres). This flight ended
with the first totally automatic, computer-controlled
re-entry, which brought the spacecraft down only about 2.8
miles (4.5 kilometres) from its recovery ship.
Launched on November 1,
1966, Gemini XII, crewed by Edwin “Buzz” Aldrin and James
Lovell, Jr., was the final flight in the series. By the time
of this four-day flight, the program still had not
demonstrated that an astronaut could work easily and
efficiently outside the spacecraft. This flight used new,
improved restraints for the astronauts to hook to outside
the spacecraft, and underwater training, which became a
staple of all future spacewalk simulations, was added as a
training technique for working in space. Aldrin totaled a
record five-and-a-half hours in space.
Agena Target Docking
vehicle seen from Gemini 8 spacecraft.
By Gemini's end, orbital
rendezvous and docking had become routine, and it seemed
clear that humans could live, work, and stay healthy in
space for days or even weeks at a time. Above all, the
program had added nearly 1,000 hours of valuable spaceflight
experience in the years between Mercury and Apollo, which by
1966 was nearing flight readiness.
Virgil I. "Gus" Grissom
John W. Young
James A. McDivitt
Edward H. White II
L. Gordon Cooper, Jr.
Charles "Pete" Conrad, Jr.
Walter M. Schirra, Jr.
Thomas P. Stafford
James A. Lovell, Jr.
Neil A. Armstrong
David R. Scott
Thomas P. Stafford
Eugene A. Cernan
John W. Young
Charles "Pete" Conrad,
Richard F. Gordon, Jr.
James A. Lovell, Jr.
Edwin E. "Buzz" Aldrin, Jr.
the red flight numbers for a detailed description of the mission