Gemini 5
Encyclopedia
Gemini 5 was a 1965 manned spaceflight in NASA
's Gemini program. It was the third manned Gemini
flight, the 11th manned American flight and the 19th spaceflight of all time (includes X-15 flights over 100 kilometres (62.1 mi)). It was also the first time an American manned space mission held the world record for duration, set on August 26, 1965, by breaking the Soviet Union's previous record set by Vostok 5
in 1963.
On August 21, 1965 at 16:07:15 UTC, the REP was released into orbit from the Gemini 5 spacecraft.
mission to eight days. This flight was crucial because the length of time it took to fly to the moon, land and return would take eight days. This was possible due to new fuel cell
s that generated enough electricity to power longer missions, a pivotal innovation for future Apollo
flights. Cooper and Conrad were to have made a practice space rendezvous
with a "pod" deployed from the spacecraft, but problems with the electrical supply forced a switch to a simpler "phantom rendezvous," whereby the Gemini craft maneuvered to a predetermined position in space. Mercury
veteran Gordon Cooper was the first person to travel on orbital missions twice. He and Conrad took high-resolution photographs for the Defense Department, but problems with the fuel cells and maneuvering system forced the cancellation of several other experiments. The astronauts found themselves marking time in orbit, and Conrad later lamented that he had not brought along a book. On-board medical tests, however, continued to show the feasibility of longer flights.
Conrad, who had a reputation for frequently having a punchline on hand, called the mission "Eight days in a garbage can." (the garbage can referring to the small size of the Gemini cabin, which was about the size of the front seat of a Volkswagen Beetle
.)
(axial oscillation of the rocket). This was measured at +0.38 g (3.7 m/s²) during stage 1 flight, exceeding the permitted +0.25 g (2.5 m/s²) for a total of about 13 seconds. The cause was traced to a pre-launch procedure and pogo never affected another Gemini flight. The initial orbit was 163 by 349 kilometres.
The first major event on the mission was the ejection of the Rendezvous Evaluation Pod (REP) at 2 hours and 13 minutes into the flight. The radar showed that the pod was moving a relative speed of two meters per second.
While out of radio contact with the ground, the crew found that the pressure in the fuel cell had dropped from 850 to 65 psi (5,860.5 to 448.2 kPa) 4 hours and 22 minutes into the flight. This was still above the 22.2 psi (153.1 kPa) minimum but Cooper decided to shut it down. Without power they would be unable to rendezvous with the REP, and it could also mean a premature end to the mission.
Tests on the ground found that it was possible for the fuel cell to work, even with low oxygen pressure. However, with the fuel cell off, they would only be able to stay in orbit for a day and still have enough battery power for reentry.
It was decided to turn the fuel cells back on and test them by using equipment that required more and more power. These showed that the fuel cells were stable and the crew could continue the mission.
In the meantime, Buzz Aldrin had been working out an alternative rendezvous test. He had a PhD in orbital mechanics and worked out a scheme where the crew could rendezvous with a "point in space".
The crew became cold as they drifted. Even with the coolant pipes in the suits turned off and the airflow on low, they still shivered. Stars slowly drifting by the windows also proved disorienting, so the crew put covers on the windows.
As with Gemini 4, the crew had trouble sleeping in alternate sleep periods. They still had little rest when they decided to take their sleep periods together.
The phantom rendezvous came on the third day. It went perfectly, even though it was the first precision maneuver on a spaceflight. They tried four maneuvers—apogee adjust, phase adjust, plane change, and coelliptical maneuver—using the orbit attitude and maneuvering system
(OAMS).
The ground crew discovered a small problem the next day. The fuel cell produced wastewater (not suitable for drinking, as it was too acidic) that was stored in a tank on board. This was the same tank used for drinking water, with the potable and non-potable water separated by a bladder wall. The problem was that the fuel cell was producing 20% more discharge than expected. However, it was soon determined that there would still be room left over at the end of the mission.
On the fifth day, a relatively major problem occurred when one of thrusters in the OAMS stopped working. This meant the cancellation of all the experiments requiring fuel. None of the attempts to resolve the thruster problem was successful.
Seventeen experiments were planned, with one cancelled, as it involved photography of the REP. Experiment D-1 involved the crew photographing celestial objects, and D-6 was a ground photography experiment. Experiments D-4/D-7 involved making brightness measurements of celestial and terrestrial backgrounds and of rocket plumes. Experiments S-8/D-13 investigated whether the crew's eyesight changed during the mission.
All the medical experiments from Gemini 4 were performed, as well as experiment M-1 into the performance of the heart. This involved Conrad wearing inflatable leg cuffs. Experiment M-9 also investigated whether the astronauts' ability to measure horizontally changed.
S-1 involved Cooper taking the first photographs of the zodiacal light
and the gegenschein
from orbit. There was also syntopic photography of Earth. One photograph of the Zagros Mountains
revealed greater detail than the official geologic map of Iran
. Experiment S-7, the Cloud-Top Spectrometer revealed that the height of clouds could be determined from orbit.
Retrofire came 190 hours 27 minutes 43 seconds into the mission over Hawaii
. They controlled the reentry, creating drag and lift by rotating the capsule. Due to a computing error, the crew landed 130 kilometers short of the planned landing point in the Atlantic Ocean. Though the computer had worked perfectly, a programmer had entered the rate of the Earth's rotation as 360° per 24 hours instead of 360.98° See Sidereal day.
The Gemini 5 mission was supported by the following U.S. Department of Defense resources: 10,265 personnel, 114 aircraft and 19 ships. Recovery was by USS Lake Champlain
.
due to the pioneering nature of the flight. The slogan "8 Days or Bust" was emblazoned across the wagon, but NASA managers objected to this, feeling it placed too much emphasis on the mission length and not the experiments, and fearing the public might see the mission as a failure if it did not last the full duration. A piece of nylon cloth was sewn over the slogan.
, Houston, Texas
.
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Gemini program. It was the third manned Gemini
Project Gemini
Project Gemini was the second human spaceflight program of NASA, the civilian space agency of the United States government. Project Gemini was conducted between projects Mercury and Apollo, with ten manned flights occurring in 1965 and 1966....
flight, the 11th manned American flight and the 19th spaceflight of all time (includes X-15 flights over 100 kilometres (62.1 mi)). It was also the first time an American manned space mission held the world record for duration, set on August 26, 1965, by breaking the Soviet Union's previous record set by Vostok 5
Vostok 5
-Backup crew:-Reserve crew:-Mission parameters:*Mass *Apogee: *Perigee: *Inclination: 64.9°*Period: 88.4 minutes...
in 1963.
Crew
Backup crew
Mission parameters
- MassMassMass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
: 3605 kilograms (7,947.7 lb) - PerigeePerigeePerigee is the point at which an object makes its closest approach to the Earth.. Often the term is used in a broader sense to define the point in an orbit where the orbiting body is closest to the body it orbits. The opposite is the apogee, the farthest or highest point.The Greek prefix "peri"...
: 162 kilometres (100.7 mi) - Apogee: 350.1 kilometres (217.5 mi)
- InclinationInclinationInclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
: 32.61° - PeriodOrbital periodThe orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
: 89.59 min
- REP (Rendezvous Evaluation Pod) sub-satellite:
On August 21, 1965 at 16:07:15 UTC, the REP was released into orbit from the Gemini 5 spacecraft.
Objectives
Gemini 5 doubled the U.S space-flight record of the Gemini 4Gemini 4
Gemini 4 was the second manned space flight in NASA's Project Gemini, occurring in June 1965. It was the tenth manned American spaceflight . Astronauts James McDivitt and Edward H. White, II circled the Earth 66 times in four days, making it the first US flight to approach the five-day flight of...
mission to eight days. This flight was crucial because the length of time it took to fly to the moon, land and return would take eight days. This was possible due to new fuel cell
Fuel cell
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used...
s that generated enough electricity to power longer missions, a pivotal innovation for future Apollo
Project Apollo
The Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...
flights. Cooper and Conrad were to have made a practice space rendezvous
Space rendezvous
A space rendezvous is an orbital maneuver during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance . Rendezvous requires a precise match of the orbital velocities of the two spacecraft, allowing them to remain at a constant...
with a "pod" deployed from the spacecraft, but problems with the electrical supply forced a switch to a simpler "phantom rendezvous," whereby the Gemini craft maneuvered to a predetermined position in space. Mercury
Project Mercury
In January 1960 NASA awarded Western Electric Company a contract for the Mercury tracking network. The value of the contract was over $33 million. Also in January, McDonnell delivered the first production-type Mercury spacecraft, less than a year after award of the formal contract. On February 12,...
veteran Gordon Cooper was the first person to travel on orbital missions twice. He and Conrad took high-resolution photographs for the Defense Department, but problems with the fuel cells and maneuvering system forced the cancellation of several other experiments. The astronauts found themselves marking time in orbit, and Conrad later lamented that he had not brought along a book. On-board medical tests, however, continued to show the feasibility of longer flights.
| Gemini 5 | REP |
|---|---|
| REP | Rendezvous Evaluation Pod |
| NSSDC ID: | 1965-068C |
| Mass | 34.5 kilograms (76.1 lb) |
| Launch date | August 21, 1965 |
| Release time | 16:07:15 UTC |
| Perigee | 162 kilometres (100.7 mi) |
| Apogee | 350.1 kilometres (217.5 mi) |
| Period | 89.59 min |
| Inclination | 32.61° |
| Reentered | August 27, 1965 |
Conrad, who had a reputation for frequently having a punchline on hand, called the mission "Eight days in a garbage can." (the garbage can referring to the small size of the Gemini cabin, which was about the size of the front seat of a Volkswagen Beetle
Volkswagen Beetle
The Volkswagen Type 1, widely known as the Volkswagen Beetle or Volkswagen Bug, is an economy car produced by the German auto maker Volkswagen from 1938 until 2003...
.)
Flight
The launch was perfect except for a few seconds of pogoPogo oscillation
Pogo oscillation is a potentially dangerous type of self-excited combustion oscillation in liquid fuel rocket engines. This oscillation results in variations of thrust from the engines, causing variations of acceleration on the rocket's structure, giving variations in fuel pressure and flow rate....
(axial oscillation of the rocket). This was measured at +0.38 g (3.7 m/s²) during stage 1 flight, exceeding the permitted +0.25 g (2.5 m/s²) for a total of about 13 seconds. The cause was traced to a pre-launch procedure and pogo never affected another Gemini flight. The initial orbit was 163 by 349 kilometres.
The first major event on the mission was the ejection of the Rendezvous Evaluation Pod (REP) at 2 hours and 13 minutes into the flight. The radar showed that the pod was moving a relative speed of two meters per second.
While out of radio contact with the ground, the crew found that the pressure in the fuel cell had dropped from 850 to 65 psi (5,860.5 to 448.2 kPa) 4 hours and 22 minutes into the flight. This was still above the 22.2 psi (153.1 kPa) minimum but Cooper decided to shut it down. Without power they would be unable to rendezvous with the REP, and it could also mean a premature end to the mission.
Tests on the ground found that it was possible for the fuel cell to work, even with low oxygen pressure. However, with the fuel cell off, they would only be able to stay in orbit for a day and still have enough battery power for reentry.
It was decided to turn the fuel cells back on and test them by using equipment that required more and more power. These showed that the fuel cells were stable and the crew could continue the mission.
In the meantime, Buzz Aldrin had been working out an alternative rendezvous test. He had a PhD in orbital mechanics and worked out a scheme where the crew could rendezvous with a "point in space".
The crew became cold as they drifted. Even with the coolant pipes in the suits turned off and the airflow on low, they still shivered. Stars slowly drifting by the windows also proved disorienting, so the crew put covers on the windows.
The phantom rendezvous came on the third day. It went perfectly, even though it was the first precision maneuver on a spaceflight. They tried four maneuvers—apogee adjust, phase adjust, plane change, and coelliptical maneuver—using the orbit attitude and maneuvering system
Orbit attitude and maneuvering system
The orbit attitude and maneuvering system was a propulsion system used in orbit by the Gemini spacecraft.-Operations:Besides providing rotation control to let a pilot steer the spacecraft, the OAMS provided translation control for the Gemini spacecraft, moving it linearly up, down, sideways,...
(OAMS).
The ground crew discovered a small problem the next day. The fuel cell produced wastewater (not suitable for drinking, as it was too acidic) that was stored in a tank on board. This was the same tank used for drinking water, with the potable and non-potable water separated by a bladder wall. The problem was that the fuel cell was producing 20% more discharge than expected. However, it was soon determined that there would still be room left over at the end of the mission.
On the fifth day, a relatively major problem occurred when one of thrusters in the OAMS stopped working. This meant the cancellation of all the experiments requiring fuel. None of the attempts to resolve the thruster problem was successful.
Seventeen experiments were planned, with one cancelled, as it involved photography of the REP. Experiment D-1 involved the crew photographing celestial objects, and D-6 was a ground photography experiment. Experiments D-4/D-7 involved making brightness measurements of celestial and terrestrial backgrounds and of rocket plumes. Experiments S-8/D-13 investigated whether the crew's eyesight changed during the mission.
S-1 involved Cooper taking the first photographs of the zodiacal light
Zodiacal light
Zodiacal light is a faint, roughly triangular, whitish glow seen in the night sky which appears to extend up from the vicinity of the sun along the ecliptic or zodiac. Caused by sunlight scattered by space dust in the zodiacal cloud, it is so faint that either moonlight or light pollution renders...
and the gegenschein
Gegenschein
The gegenschein is a faint brightening of the night sky in the region of the antisolar point.- Explanation :Like the zodiacal light, the gegenschein is sunlight reflected by interplanetary dust...
from orbit. There was also syntopic photography of Earth. One photograph of the Zagros Mountains
Zagros Mountains
The Zagros Mountains are the largest mountain range in Iran and Iraq. With a total length of 1,500 km , from northwestern Iran, and roughly correlating with Iran's western border, the Zagros range spans the whole length of the western and southwestern Iranian plateau and ends at the Strait of...
revealed greater detail than the official geologic map of Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
. Experiment S-7, the Cloud-Top Spectrometer revealed that the height of clouds could be determined from orbit.
Retrofire came 190 hours 27 minutes 43 seconds into the mission over Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
. They controlled the reentry, creating drag and lift by rotating the capsule. Due to a computing error, the crew landed 130 kilometers short of the planned landing point in the Atlantic Ocean. Though the computer had worked perfectly, a programmer had entered the rate of the Earth's rotation as 360° per 24 hours instead of 360.98° See Sidereal day.
The Gemini 5 mission was supported by the following U.S. Department of Defense resources: 10,265 personnel, 114 aircraft and 19 ships. Recovery was by USS Lake Champlain
USS Lake Champlain (CV-39)
USS Lake Champlain was one of 24 s completed during or shortly after World War II for the United States Navy. She was the second US Navy ship to bear the name, and was named for the Battle of Lake Champlain in the War of 1812....
.
Insignia
This was the first mission to have an insignia patch. After Gemini 3, NASA barred astronauts from naming their spacecraft. Cooper, having realized he had never been in a military organization without one, suggested a mission patch to symbolize the flight. NASA agreed, and the patches got the generic name of "Cooper patch." Cooper choose the image of a covered wagonConestoga wagon
The Conestoga wagon is a heavy, broad-wheeled covered wagon that was used extensively during the late 18th century and the 19th century in the United States and sometimes in Canada as well. It was large enough to transport loads up to 8 tons , and was drawn by horses, mules or oxen...
due to the pioneering nature of the flight. The slogan "8 Days or Bust" was emblazoned across the wagon, but NASA managers objected to this, feeling it placed too much emphasis on the mission length and not the experiments, and fearing the public might see the mission as a failure if it did not last the full duration. A piece of nylon cloth was sewn over the slogan.
Spacecraft location
As of 2006, the spacecraft is on display at Space Center HoustonSpace Center Houston
Space Center Houston is the official visitors' center of the Lyndon B. Johnson Space Center—the National Aeronautics and Space Administration's center for human spaceflight activities—located in Houston...
, Houston, Texas
Houston, Texas
Houston is the fourth-largest city in the United States, and the largest city in the state of Texas. According to the 2010 U.S. Census, the city had a population of 2.1 million people within an area of . Houston is the seat of Harris County and the economic center of , which is the ...
.
See also
- SplashdownSplashdown (spacecraft landing)Splashdown is the method of landing a spacecraft by parachute in a body of water. It was used by American manned spacecraft prior to the Space Shuttle program. It is also possible for the Russian Soyuz spacecraft and Chinese Shenzhou spacecraft to land in water, though this is only a contingency...
- Space capsuleSpace capsuleA space capsule is an often manned spacecraft which has a simple shape for the main section, without any wings or other features to create lift during atmospheric reentry....
- Space explorationSpace explorationSpace exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....
- U.S. space exploration history on U.S. stampsU.S. space exploration history on U.S. stampsWith the advent of unmanned and manned space flight a whole new era of American history had presented itself. Keeping with the tradition of honoring the country's history on the face of U.S. postage stamps, the U.S. Post Office began honoring the various events with its commemorative postage stamp...
External links
- Gemini 5 Mission Report (PDF) October 1965
- NASA Gemini 5 press kit - August 12, 1965
- Gemini 5 in On The Shoulders of Titans: A History of Project Gemini
- Spaceflight Mission Patches: http://www.genedorr.com/patches/Intro.html
- NASA data sheet: http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=1965-068A
- U.S. Space Objects Registry http://usspaceobjectsregistry.state.gov/search/index.cfm