
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.

Important Missions
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."

Main Parts
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.

Levels
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.

Robotic Arm
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.

Space Suit
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.

Launch
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.

Crew
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.

Landing
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.