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Man in Space A National Historic Landmark Theme Study

Apollo 11 Command Module
(Courtesy of NASA)

Mercury Spacecraft Friendship 7,
Gemini 4 Spacecraft, and
Apollo 11 Command Module

DESCRIPTION

Friendship 7 — Mercury MA-6

Mercury Friendship 7 Spacecraft is a cone-shaped vehicle 9 feet long, 6 feet 7 inches in diameter at the base weighing 2000 pounds. Friendship 7 was built by the McDonald Aircraft Corporation of St. Louis for Project Mercury—America's program to send a man in to orbit around the Earth.

Atop the manned portion of the cone was a small cylinder containing the parachute, and above that, an antenna can. Straddling the antenna can was a tower with two solid propellant rockets, one an escape rocket to propel the entire capsule away from the launch vehicle in case of emergency prior to launch, and the other a tower jettison rocket to remove the tower and escape rocket after successful launch. [1]

The bottom of the cone of the Friendship 7 Spacecraft is covered with a heat shield composed of an ablating fiberglass material. Strapped to the base of the capsule were three accelerating rockets for separating the spacecraft from the launch vehicle and three decelerating solid rockets for return to Earth. All of these rockets were designed to be jettisoned just prior to reentry. [2]

Inside the Friendship 7 Spacecraft there is an astronauts couch and a three piece instrument panel. A trapezoidal window is cut into the skin of the spacecraft between the astronaut and the instrument panel to permit a wide field of view during flight.

Gemini 4 Spacecraft

The Gemini 4 Spacecraft was designed for two astronauts instead of one. It is 11 feet high and 7-1/2 feet in diameter at its base and was built by McDonald Aircraft Corporation of St. Louis.

The Gemini Spacecraft was composed of two modules: the reentry module which included the spacecraft cabin, and the adapter module which was jettisoned prior to reentry. [3]

The reentry module includes the spacecraft cabin, control systems, thrusters for orientating the spacecraft during reentry, and parachutes. The Gemini Spacecraft Cabin contains 50 cubic feet of space and has two overhead hatches for egress during spaceflight for EVA. The floor of the cabin has a forward trapezoidal panel upon which the crew's feet rested, and an aft hatch below the seat pans of the couches which open into a compartment containing part of the environmental control system. The bottom of the reentry module contains the heatshield for reentry. During reentry the adapter module was jettisoned. [4]

Apollo 11 Command Module

The Apollo 11 Command Module is 10 feet 7 inches high and 12 feet 10 inches wide at its base. It weighs 14,000 pounds and was built by North American Rockwell.

There are three sections to the command module: the forward section at the apex of the cone, housing two negative pitch reaction control engines and components of the Earth landing system; the middle section containing crew accommodations, controls and displays, and aircraft systems; and the third, or aft, section around the periphery of the cone near the base containing ten reaction control engines and propellant tanks. Total living volume for the three astronauts is 210 cubic feet. The heat shield on the Apollo 11 Command Module consists of a fiberglass honeycomb filled with an elastomeric ablator, over a stainless steel structure. [5]

During flight the Command Module was attached to the Service Module which contained the service propulsion system and reaction control fuel-oxydizer tanks, fuel cells for electric power, cyrogenic oxygen, hydrogen, and onboard consumables. [6] The Service Module was jettisoned prior to reentry and not recovered.

STATEMENT OF SIGNIFICANCE

The Mercury Spacecraft Friendship 7, Gemini 4 Spacecraft, and Apollo 11 Command Module are nationally significance because they collectively represented the three classes of spacecraft that were constructed to carry Americans into space and eventually toward the goal of the first manned landing on the Moon in July 1969. All three spacecraft are the actual flight vehicles used in their respective missions. They each carried one or more crew members and were the only parts of the space flight hardware designed to be recovered. Each of these space craft represented a first or breakthrough for its series. For example, Friendship 7 carried John Glenn into space in 1962 as the first American to orbit the Earth; Gemini 4 carried Ed White and saw the completion of his "walk in space", Apollo 11 carried the first men to land on the surface of the Moon. In recognition of these achievements each of these spacecrafts is now housed in the Milestones of Flight Gallery of the National Air and Space Museum in Washington, DC.

GENERAL HISTORY [7]

Mercury Spacecraft Friendship 7

On February 20, 1962, John H. Glenn, Jr., became the first American to orbit the Earth. He accomplished this feat in the Mercury spacecraft Friendship 7. A modified Atlas missile was the booster.

On the day of the launch, Glenn boarded Friendship 7 at 6:06 a.m. EST. Minor problems delayed the launch several times, but the countdown was completed at 9:47 a.m. and all engines of the Atlas ignited. Five minutes later, John Glenn was in orbit. He checked the spacecraft and found all systems performing as expected.

Near the end of his first orbit, Glenn noticed that Friendship 7 drifted slowly to the right when the automatic control system was on. He switched to manual control and corrected the problem. Mission controllers were pleased about the way Glenn resolved the problem, but they were faced with a potentially far more serious one.

An instrument light at mission control indicated that the heatshield and compressed landing bag were loose. If this were true, Friendship 7 and its human cargo would be incinerated during atmospheric entry. There was a solution. The retro-rocket package was strapped to the heatshield; if the package were retained after retro-fire, its straps would hold the heatshield in place. By the time pack burned away, aerodynamic pressure would keep the shield from slipping.

Four and a half hours after launch, Glenn was nearing the end of his flight. All three retro-rockets fired while Friendship 7 was over California, slowing it enough to enter the atmosphere. As the heat of entry increased, Glenn saw bits of the retro-package fly past his window. When one of the straps swung in front of the window he knew the package was gone.

The glass-fiber and resin ablative heatshield did its job — Friendship 7 survived reentry. At an altitude of 28,000 feet, the drogue parachute opened, followed by the main one at 10,000 feet. Glen flipped the landing bag release switch and felt a reassuring "clunk" as the bag and heatshield dropped into position. The premature deployment signal had been nothing more serious than a fault in the ground controller's console.

Friendship 7 splashed down in the Atlantic Ocean 4 hours and 55 minutes after launch. Seventeen minutes later, the destroyer USS Noa was floating alongside, ready to retrieve the bobbing spacecraft. Once the craft was cradled in a mattress pallet on Noa's deck, Glenn fired the explosive bolts holding the hatch in place. When the hot, tired astronaut emerged from the spacecraft, America had a new hero.

Gemini 4 Spacecraft

Astronaut Edward H. White II became the first American to "walk in space on June 3, 1965. His 22-minute extravehicular activity was one of the most dramatic accomplishments of the United States' manned program. White strolled over North America during the third orbit of the four-day flight of Gemini 4.

Gemini 4 was launched from pad 19 at the Kennedy Space Center (formerly Cape Canaveral) in Florida at 10:16 a.m. EST on June 3, 1965. Less than 10 minutes after lift off, the Titan 2 booster had placed the spacecraft in a 100- by 175-mile high orbit. James A. McDivitt was Gemini 4's command pilot, Edward White was the pilot.

The two-man Gemini was an intermediate step between the single seat Mercury earth-orbiting spacecraft, and the three-man Apollo lunar vehicle. Project Gemini's objectives were to demonstrate the techniques of orbital rendezvous and docking, conduct missions lasting up to two weeks, and to conduct extravehicular activities, or "space walks." Such operations would be needed in a few years for the Apollo lunar flights.

During the third orbit, McDivitt and White depressurized Gemini 4's cabin, and at 2:45 p.m. EST, White opened his hatch and stood up. He had several pieces of specialized equipment for the extravehicular activity. A 25-foot long gold-colored "umbilical," connected him to the spacecraft. The umbilical contained his oxygen supply hose and electrical leads. White wore an emergency oxygen pack on his chest. If anything went wrong with the umbilical, the pack held a 9-minute oxygen supply. His helmet had a gold-plated outer visor to protect him from the intense ultraviolet radiation from the sun. White also had a small hand-held maneuvering unit.

Soviet Cosmonaut Alexi Leonov had performed the first walk in March 1965 (less than three months before White) and had spent ten minutes floating alongside Voskhod-2, but he did not have any means of controlling his movements. White used his maneuvering unit to pull himself out of the cabin, then translated the length of the spacecraft, and practiced several turns before running out of propellant. The maneuvering unit comprised two tanks with a throttle handle and three thrusters. White spent 22 minutes outside of Gemini 4 before Mission Control ordered him back inside.

After the excitement of the extravehicular activity, McDivitt and White undertook the rest of the mission, which lasted for four days. During the rest of the flight, the astronauts performed medical experiments, photographed Earth, and evaluated the spacecraft's systems. After circling Earth 62 times, Gemini 4 splashed down in the Atlantic Ocean at 12:12 p.m. EST on June 7, 1965. The aircraft carrier USS Wasp recovered the craft, which had traveled a total distance of 1,609,700 miles in space

Apollo 11 Command Module

The Apollo 11 Command Module Columbia was the living quarters for the three-man crew during most of the first manned lunar landing mission in July 1969. On July 16, 1969, Neil Armstrong, Edwin "Buzz" Aldrin, and Michael Collins climbed into Columbia for their 8-day journey. The Command Module was one of three parts of the complete Apollo spacecraft. The other two were the Service Module and the Lunar Module.

The Service Module contained the main spacecraft propulsion system and consumables (oxygen, water, propellants, and hydrogen). The Lunar Module was the part Armstrong and Aldrin would use to descend to the moon s surface.

When Apollo 11 lifted off, the spacecraft and launch vehicle combination stood 364 feet tall. Eight days later, when the flight ended, the only part recovered was the 11-foot tall Columbia Command Module.

For the launch, the Lunar Module was stored in a cone-shaped adapter between the Service Module and the launch vehicle. Once the spacecraft was on its way to the moon, the Command and Service Modules (CSM) pulled away from the adapter, turned around, then moved back in to dock with the lunar lander. When the two were linked, the astronauts could crawl between craft via a docking tunnel in the top of the Command Module. After the CSM/Lunar combination reached the moon, Armstrong and Aldrin entered the Lunar Module and undocked from Columbia. Collins remained in lunar orbit aboard Columbia, while his crewmates landed on the surface.

When their surface activities were over, Armstrong and Aldrin took off and rejoined Collins. They fired the CSM's large engine and headed back to Earth. Several days later, on July 24, they discarded the Service Module and entered Earth's atmosphere. Columbia's exterior is covered with an epoxy-resin ablative heatshield. As Columbia entered the atmosphere at a speed of 25,000 miles per hour, its exterior reached a temperature of 2,760°C (5,000°F). This heatshield protected the craft from burning and vaporizing. Columbia finished its flight with a parachute landing in the Pacific Ocean, where USS Hornet retrieved it and its crew.

FOOTNOTES

1. U.S., Congress, House, United States Civilian Space Program 1958-1978, Vol. 1. 97th Cong., January 1981, p. 348.

2. Ibid.

3. Ibid., p. 362

4. Ibid.

5. Ibid., p. 388

6. Ibid., p. 389

7. All of the historical material given below for the Mercury Spacecraft Friendship 7, Gemini 4, and Apollo 11 Command Module has been taken from the following source.

Gregory P. Kennedy, Rockets, Missiles and Spacecraft of the National Air and Space Museum (Washington, DC: Smithsonian Institution Press, 1983), pp. 84, 96, and 122.

BIBLIOGRAPHY

Brooks, Courtney G., Grimwood, James M., and Swenson, Loyd S. Chariots for Apollo: A History of Manned Lunar Spacecraft. Washington, DC: National Aeronautics and Space Administration, 1979.

Hacker, Barton C. and Grimwood, James M. On the Shoulders of Titan: A History of Project Gemini. Washington, DC: National Aeronautics and Space Administration, 1979.

Kennedy, Gregory P. Rockets, Missiles and Spacecraft of the National Air and Space Museum. Washington, DC: Smithsonian Institution Press, 1983.

Swenson, Loyd S. Jr., Grimwood, James M., and Alexander, Charles C. This New Ocean: A History of Project Mercury. Washington, DC: National Aeronautics and Space Administration, 1966.

U.S. Congress, House. United States Civilian Space Programs 1958-1978 Vol. 1.97th Congress, 1st Session, January 1981.

Photo used on this page courtesy of NASA.

Last Modified: Mon, Jan 8 2001 10:00:00 am PDT
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