The space shuttle is a spacecraft designed for transporting people and cargo to and from orbit around Earth. NASA built the shuttle in the 1970’s to serve as a reusable rocket that could fly many missions. Past spacecrafts could only be used one time.
After 10 years of preparing Columbia, the first space shuttle was launched on April 12, 1981. Now four space shuttles are in use—Columbia (1981), Discovery (1983), Atlantis (1985), and Endeavour (1991), which replaced Challenger.
Two of the most important missions for a space shuttle are to carry satellites and other equipment into space and repair them there if necessary and to allow astronauts to conduct space experiments for studying weightlessness called "microgravity."
The space shuttle has three main parts—the orbiter, rocket systems (two solid rocket boosters and three main engines), and an external fuel tank. The orbiter has the crew cabin (which can carry up to seven crew members) the cargo bay, and the three main engines. Located on each side of the shuttle, the solid booster rockets holds solid fuel. When the fuel is gone, the boosters fall back down to Earth. The external fuel tank holds the shuttle’s liquid fuel.
The space shuttle has three levels—the flight deck, the mid-deck, and the utility floor. The flight deck is where the mission commander and the pilot control the shuttle. The astronauts sleep, eat, and go to the bathroom on mid-deck. The utility floor storage area is where they keep the water and air tanks. The cargo bay is large enough to fit a tour bus. The laboratory is located in the cargo bay on the utility floor. That is where the satellites are stored and experiments are conducted. The cargo bay is where they complete all the missions. For example if one of their missions was to repair a satellite, the astronaut would fix it in the cargo bay.
Heat Shield Tiles
The space shuttle is covered with special tiles to protect it from the intense heat when it reenters the Earth’s atmosphere. The tiles are so safe that if exposed to temperatures of up to 2,300° F, a human could hold them in their bare hand without injury! The tiles can last for up to 100 missions. Without these tiles, the space shuttle would burn to a crisp, killing all the astronauts inside.
Located on the left side of the space shuttle is a Canadian built robotic arm. It is used to pick up satellites and astronauts. The arm has three moving joints similar to the human wrist, elbow, and shoulder. The arm stretches fifty feet in length. It has two video cameras used to record the activities of the crew. The robotic arm has been a very important tool because it was used to build and repair the Russian space station, Mir, and the International Space Station.
Astronauts wear space suits and maneuvering units. These units strap on to an astronaut’s back over the space suit, allowing them to move around in space without being connected to the shuttle. This equipment allows astronauts to take space walks outside the shuttle to work on satellites and other equipment.
Space shuttles are designed to leave Earth vertically using rockets and to land horizontally a lot like an aircraft. The booster rockets take the shuttle 28 (45 km) miles high before they fall away. These engines are designed to be used for 55 space missions, the world’s first reusable rocket engines. The speed of the rockets reaches 3,049 mph (4,973 km/h) before they burn out and fall into the ocean. After the booster rockets fall away, the three main shuttle engines kick in.
The mission commander and the pilot, who are responsible for flying the shuttle, lead the flight crew. The rest of the crew is responsible for making sure the mission completes all of its assignments. Payload specialists conduct experiments or launch and repair satellites or other equipment.
The space shuttle usually lands back at Kennedy Space Center in Cape Canaveral, Florida. If there is bad weather or other problems, the shuttle can land at Edwards Air Force Base in California. Shuttles that land at Edwards have to be carried back to Cape Canaveral by a special Boeing 747 at a cost of nearly $1 million.
The ISS and the Shuttle Working Together
The International Space Station (ISS) is a spacecraft where astronauts could live and work. Since the ISS is large, it is less expensive to take it piece by piece into space and assemble it there rather than build the entire station and launch it into space. In the year 2002, after 44 flights into space, the ISS will be finished.
The center of the ISS is the U.S. Destiny Laboratory. This is where new and extraordinary experiments will be done in near-zero gravity.
The first piece of the ISS put into space was the Zarya control module, launched on November 20, 1998. It was put into orbit by a Russian Proton rocket. Zarya will provide power and communication and help dock other parts of the station. Following this mission, the Endeavour carried the Unity connecting module into space. Unity allows the pieces of the ISS to connect together.
One day the new X-33 will replace the space shuttle. It is only half the size of a space shuttle. NASA is conducting test flights now.
Space Shuttle Names
Each space shuttle was named after a famous ship.
Unless otherwise noted, all images courtesy of NASA. Permission for use at http://www.nasa.gov/gallery/photo/guideline.html.
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