Space Travelers
An astronaut is a person who pilots a spacecraft or works in space to
complete a mission. Russian astronauts are called cosmonauts. French astronauts
are called spacetionauts. The word astronaut comes from Greek words that mean
sailor among the stars. Cosmonaut means sailor of the universe.
There are three different kinds of astronauts—pilots, mission specialists,
and payload specialists. A pilot commands and pilots the spacecraft. Most pilot
astronauts are test pilots from the United States Air Force, Navy, or Marines.
Mission specialists conduct experiments, launch satellites, and perform
spacewalks. Another kind of astronaut is called a payload specialist. Payload
specialists carry out scientific experiments with the payload (cargo) on the
spacecraft. Most payload specialists are scientists approved by NASA.
Selecting Astronauts
The first astronauts and cosmonauts were selected only from military pilots.
On August 1, 1985, NASA began accepting applications for pilot astronauts and
mission specialist astronauts from scientists, engineers, medical doctors, and
educators as well. Before that time, astronauts were selected in groups of 7 to
35 people. All astronauts in space shuttles must be able to speak English. There
is no age limit, but all candidates must pass the NASA space flight physical.
Pilot astronaut candidates require 1,000 hours as a command pilot in
high-performance jet aircraft. They also must be between 5 feet 4inches and 6
feet 4 inches tall. Mission specialist candidates do not need flight experience
like pilot astronauts, but they must have at least three years of professional
experience related to the mission. They must be between 5 feet and 6 feet 4
inches tall. Payload specialists must have the education and training to conduct
their experiments.
Training
Astronauts have to train for every possible emergency. They also need to
become familiar with the spacecraft and instruments that they will be using and
the tasks that they expect to perform before they go into space.
Flight training is done in jet aircrafts. Mission specialist candidates
receive less flight training than scientist astronauts selected in 1966 and
1967. Scientist astronauts had to complete one year of military flight training
before NASA accepted them to fly in space. Astronauts have been trained for
weightlessness. Today, pilot and mission specialist candidates experience the
near absence of gravity as large planes fly through a series of arcing climbs
and dives. For about 30 seconds during each arc, they float weightlessly in the
padded body of the aircraft. Floating in water also simulates (reproduces
conditions of) weightlessness.
Mission training involves the study of cockpit layout and flight-controls
systems, engineering work, and familiarity with the equipment. During such
training, candidates are assigned to space flight systems and support
activities. They are evaluated (checked) on their performance of these tasks
raining. The evaluations determine whether or not the candidates will be
accepted as astronauts. Becoming an astronaut does not guarantee immediate
assignment to a mission. Some pilots have waited as long as 12 years before
flying in space. While waiting, astronauts continue to work on various
engineering assignments. Some astronauts become experts in several support or
operational areas. Such special knowledge helps astronauts get assigned to
flights on which their specialty is necessary. Once assigned to a crew,
astronauts spend most of their time training in simulators. Simulators are
devices that reproduce the conditions of space flight. Crewmembers spend as many
as eight hours a day in simulators rehearsing every part of their mission.
Instructors continually give the crew problems to solve and correct to prepare
them for all possible emergency situations. Astronauts spend more time in
simulators than in space. They regard the simulators as valuable preparation for
what they will later face on actual flights. For example, the Apollo 13
astronauts used the oxygen and power supply of their lunar module to return home
safely after an explosion damaged their main spacecraft. This operation was less
difficult to carry out because the crew had practiced it in simulators.
Astronauts also train in mock-ups. Mock-ups are full sized models of the
spacecraft. They help crewmembers practice working and living in the close
quarters of the spacecraft. Astronauts store items, prepare food, and check
equipment in the mock-ups. They also practice entering and leaving the
spacecraft. Rookie astronauts may spend as long as 18 months training for a
mission. Astronauts who already have traveled in space may need only 6 months of
training before they are ready to fly again.
Special training prepares astronauts for tasks that are not part of all
missions. For example, astronauts involved in the 1975 U.S.-Soviet Apollo-Soyuz
Test Project learned the Russian language and participated in flight simulations
in both the United States and the Soviet Union. Astronauts who worked in the
Spacelab or on Mir practice operating special equipment and instruments needed
to conduct scientific and engineering experiments. Some shuttle astronauts train
with jet-powered backpacks to practice flying away from and back to their
spacecraft without a safety line. A safety line connects an astronaut to the
space shuttle so the astronaut will not keep on going into space.
Going through all of this takes a lot of time and work, but this training
helps astronauts to successfully carry out their missions and help improve our
lives on Earth.
