NASA from Skylab to the International Space Station
"An Act to provide for research into the problems of flight within and outside the Earth's atmosphere, and for other purposes." With this statement, the Congress and the President authorized the establishment of the National Aeronautics and Space Administration (NASA) on October 1, 1958.
The National Aeronautics and Space Administration (NASA) is a federal agency of the United States government responsible for the country’s civilian space program. It was formally established on July 29, 1958 when President Eisenhower signed the National Aeronautics and Space Act.
After the successful moon landings of the Apollo program, NASA moved into a new phase of science and space exploration beginning with Skylab.
Skylab was America’s first orbiting space station. Originally conceived in 1965, the station was built from a Saturn 1B upper stage. The one hundred and seventy thousand pound station with a habitable volume of 11,290 cubic feet was assembled on earth and launched in May 1973 atop the first two stages of a Saturn V. It entered into a 235 mile orbit and was occupied for one hundred and seventy-one days by three crews from 1973-1974. The missions (SL-2, SL-3 and SL-4) were 28, 59 and 84 days long respectively. Skylab included an Apollo Telescope Mount with multi-spectral solar observatory, Multiple Docking Adapter, Airlock Module and Orbital Workshop. The station was powered by solar rays with some assistance from fuel cells aboard the docked Apollo spacecraft.
NASA planned to have the Shuttle dock with Skylab and push it into a higher orbit, but the Shuttle wasn’t ready in time for the mission. Skylab slipped out of orbit on July 11, 1979 and disintegrated in the atmosphere spreading debris across a wide swath of Western Australia.
On May 24, 1972, President Nixon and Soviet Premier Kosygin agreed to a joint space mission between the United States and the Soviet Union. The mission, primarily a symbol of détente, involved the docking of an Apollo Command/Service Module with a Soyuz spacecraft. The mission took place in July 1975 and involved a number of scientific experiments. Ironically, Deke Slayton, one of the original seven Mercury astronauts, finally got his chance to fly into space when he joined the Apollo-Soyuz mission. Slayton was grounded from previous missions for medical reasons.
Space Shuttle Program (1981-2011)
The Space Shuttle Program became NASA’s main focus in manned space flight from the late 1970’s well into the twenty-first century. It was designed as a reusable space vehicle that was launched like a rocked and returned as a gliding plane. Six shuttles were built including Enterprise, Columbia, Challenger, Discovery, Atlantis and Endeavor. Columbia was the first shuttle to formally launch into space on April 12, 1981. (The Enterprise was used for flight and landing tests after being dropped from a 747 jet, but it never flew into space.)
The Space Shuttle was launched with an external liquid propellant tank and two solid rocket boosters. The shuttle operated in low earth orbit from 115 to 400 miles and could carry a maximum payload of 54,000 pounds. Mission length could last from five to seventeen days with a crew of between two and eight astronauts.
The Space Shuttle fleet flew 135 missions. Two shuttles and fourteen crewmembers were lost in mission disasters: Challenger exploded seventy-three seconds after liftoff on January 28, 1986 and Columbia broke apart sixteen minutes before landing on February 1, 2003.
The Space Shuttle program ended on July 21, 2011 when Atlantis touched down at the Kennedy Space Center. The three decade long program involved more than three hundred astronauts.
The Enterprise is currently on display at the U.S.S Intrepid Air and Space Museum in New York City. Discovery will replace Enterprise at the Air and Space Museum. Endeavor is on display at the California Science Center and Atlantis will be displayed at the Kennedy Space Center.
International Space Station (1998-present)
The International Space Station (ISS) was primarily designed to be a space based laboratory, observatory and factory. It was also intended to be a staging base for future deep space missions to the moon, mars and beyond.
The International Space Station (ISS) is a combination of the Japanese Kibo laboratory, the Russian Mir-2, the American Freedom and the European Columbus. The station primarily consists of modules, external trusses and solar arrays.
The station is divided into two sections, the Russian Orbital Segment (ROS) and the United States Orbital Segment (USOS) which is jointly shared by several countries. The U.S. Orbital segment was completed in 2011 and the Russian segment is scheduled to be finished by 2016. Ownership and use of the station has been established by agreements and treaties.
The ISS is an orbiting research laboratory where crew members conduct experiments in biology, physics, astronomy, meteorology and other areas. The ISS is also capable of testing systems and equipment for various space missions. The station orbits the earth at an altitude between 205 miles and 410 miles and completes almost sixteen orbits per day. The station is so large it can often be seen with the naked eye from earth.
Crew members assigned to an ISS Expedition usually spend six months in space. The ISS has so far seen crew members from fifteen different nations. Crews were originally limited to three members but have been increased to six since 2009. Crew size will expand to seven once the Commercial Crew Development Program (CCDev) becomes active. The CCDev program was started in 2010 in order to create commercially operated spacecraft capable of reaching the ISS.
With the retirement of the Space Shuttle the Soyuz spacecraft is the prime delivery vehicle for the ISS. The Soyuz craft stays docked with the station till it’s time to return the crew members to earth. The ISS has been funded till 2020 and may be extended till 2028 and beyond.
NASA is currently developing a new generation of manned vehicles with greater emphasis on private sector development.