Space exploration is the physical exploration of outer space. The politics, science, and engineering behind space flight all fall under the auspices of space exploration. There are many rationales behind space exploration; among the most common are ones focusing on scientific research or the future survival of humanity.
This endeavor has been to some degree a dream and goal of humanity for the past several centuries, but it was not until the development of large liquid-fueled rocket engines during the early 20th century that it really became possible.
The Solar System, showing the Sun, Inner Planets, Asteroid Belt, Outer Planets, and a comet
The first major milestone of this endeavor was the launch of the USSR's Sputnik 1 on October 5, 1957, the first man-made object to orbit the Earth. After this event, the USA declared itself to be in a space race with the Soviet Union.
Major achievements of the first era of space exploration (which lasted until 1969) were:
- First man in space, (Yuri Gagarin aboard Vostok 1) on April 12, 1961 (again by the USSR).
- Frst spacewalk (by Alexei Leonov, also a Soviet cosmonaut) in 1965.
- First Moon landing by Neil Armstrong and Buzz Aldrin aboard Apollo 11 on July 20, 1969 (by the USA).
- The next notable achievement in space was the launch of first space station, Salyut 1, from the USSR.
After the first 20 years of exploration, focus began shifting from one-off flights to renewable hardware, such as the Space Shuttle program, and from competition to cooperation as on the International Space Station. Recently, private interests have begun pushing space tourism, while larger government programs have been advocating a return to the Moon and possibly missions to Mars in the near future.
Space Exploration Exhibit
James Spellman, Jr., DAFC, GS-11, 60th Medical Group Public Affairs, David Grant USAF Medical created the Space Exploration exhibit at Travis Heritage Center. The following is his background text on the Aerojet General XLR-73 rocket engine, Projects Mercury and Gemini.
Aerojet General XLR73
Prototype Rocket Engine for the X-15 research program.
The famed X-15 research aircraft project -- the “grandfather” of today’s Space Shuttle -- had somewhat of a problem during its earliest stages of development, when the Wright Air Development Center (Wright-Patterson AFB, Ohio) Power Plant Laboratory pointed out the lack of an acceptable rocket engine as a major shortcoming of the original proposal by the National Advisory Committee of Aeronautics (forerunner of today’s National Aeronautics and Space Administration, or NASA). The laboratory suggested several rocket engines “more suitable” for manned aircraft, but essentially WADC urged further study before the final selection of a specific engine.
In October 1954, representatives from the Air Force, Navy, and NACA, who were planning the X-15 design competition, selected four rocket-powered engines as possibilities.
The original list included the Aerojet General XLR73 -- seen here on display -- the Bell Aircraft XLR81, North American Aviation's NA-5400 and Reaction Motors' XLR10.
Of the four rocket engines under consideration, only the Aerojet XLR73 was a funded development engine. Consequently, the XLR73 was the only engine which -- theoretically at least -- would have cost nothing additional in total program costs.
The engine ultimately selected for the X-15 program was not one of the four originally presented, but the Reaction Motors XLR99.
The Mercury Monument honoring the original seven astronauts
is shown here at sunrise at Pad 14 - December 18, 1964.
Initiated in 1958 and completed in 1963, Project Mercury was the United States' first man-in-space program. The objectives of the program, which made six manned flights from 1961 to 1963, were simple:
- to orbit a manned spacecraft around Earth.
- to investigate man's ability to function in space.
- to recover both man and spacecraft safely.
The Travis Heritage Center displays a full-scale representation of the one-man Mercury spacecraft flown by the “Original 7” astronauts from 1961 to 1963. Built by McDonnell Aircraft of St. Louis, Missouri, for the National Aeronautics and Space Administration, a typical Mercury spacecraft measured 11 feet, 6 inches long with a diameter of 6 feet, 2 inches and weighs 1,356 pounds.
Project Mercury is considered by many as the beginning of the golden age of space exploration.
Astronaut Alan B. Shepard, Jr. (Lt. Cmdr, USN) became America’s first astronaut aboard Freedom 7 on May 5, 1961 during a 15-minute suborbital flight.
Astronaut Virgil I. “Gus” Grissom (Capt, USAF) followed suit on another suborbital flight aboard Liberty Bell 7 on July 21, 1961. Unfortunately, Liberty Bell 7 sank in the waters of the Atlantic Ocean when the escape hatch prematurely opened shortly after splashdown. However, almost 40 years to the day - at a depth of three miles - the spacecraft was found and recovered on July 20, 2001.
Astronaut John H. Glenn, Jr. (Lt. Col, USMC) became the first American to orbit the Earth aboard Friendship 7 on February 20, 1962.
Astronaut M. Scott Carpenter (Lt. Cmdr, USN) performed a similar three-orbit mission aboard Aurora 7 on May 24, 1962.
With increasing confidence, the flight envelope was expanded by Astronaut Walter M. Schirra, Jr. (Lt. Cmdr, USN) during a six-orbit “textbook” mission aboard Sigma 7 on October 3, 1962.
The longest Mercury mission on record closed out the program on May 15-16, 1963 when Astronaut Leroy Gordon Cooper, Jr. (Maj, USAF) flew 22 orbits over 35 hours aboard Faith 7.
Astronaut Donald K. “Deke” Slayton (Capt, USAF) was originally grounded from flying a Mercury mission due to a heart murmur condition. He became the chief of the Astronaut office, responsible for the crew selections of the Gemini, Apollo and Skylab missions – until he returned to flight status as NASA’s “oldest rookie” to fly the Apollo-Soyuz Test Project mission in 1975.
On December 7, 1961, the National Aeronautics and Space Administration (NASA) announced a plan to extend the existing manned space flight program by the development of a two-man spacecraft. The program was officially designated Gemini on January 3, 1962. Project Gemini was the second human spaceflight program of the United States of America. It operated between Projects Mercury and Apollo, during the years 1963-1966.
Gemini 6 Views Gemini 7
NASA successfully completed its first rendezvous mission with two Gemini spacecraft - Gemini VII and Gemini VI - in December 1965. This photograph, taken by Gemini VII crewmembers Frank Lovell and Frank Borman, shows Gemini VI in orbit 160 miles (257 km) above Earth. The main purpose of Gemini VI, crewed by astronauts Walter Schirra and Thomas Stafford, was the rendezvous with Gemini VII. The main purpose of Gemini VII, on the other hand, was studying the long-term effects of long-duration (up to 14 days) space flight on a two-man crew. The pair also carried out 20 experiments, including medical tests. Although the principal objectives of both missions differed, they were both carried out so that NASA could master the technical challenges of getting into and working in space.
The Gemini Program was needed after it became evident to NASA officials that an intermediate step was required between projects Mercury and Apollo. The model on display here is a 1/5th scale representation of the two-man spacecraft.
The major objectives assigned to Gemini were:
- To subject two men and supporting equipment to long-duration flights, a requirement for projected later trips to the Moon or deeper space.
- To effect rendezvous and docking with other orbiting vehicles, and to maneuver the docked vehicles in space, using the propulsion system of the target vehicle for such maneuvers.
- To perfect methods of reentry and landing the spacecraft at a pre-selected land-landing point.
- To gain additional information concerning the effects of weightlessness on crew members and to record the physiological reactions of crew members during long-duration flights.
After 10 successful flights, the Gemini program clearly placed the United States in the lead over the Soviet Union in manned space flight. The flight of Gemini VIII included the successful emergency recovery of the tumbling orbiting capsule by Neil Armstrong.”