How astronauts work?

Astronauts' missions

The very first astronauts were little more than human test subjects, but today’s astronauts are pilots, scientists, and engineers with active roles in many aspects of their missions. In the first ever piloted spaceflight, Vostok 1, cosmonaut Yuri Gagarin had little more to do than go along for the ride while a ground crew controlled the spacecraft by remote control. The instruments had an override code that Gagarin could have used if something went wrong, but he did not know the code before the flight. It was sealed in an envelope attached to the capsule’s wall. The first U.S. astronauts—those in the Mercury program—had some control over their spacecraft. Alan Shepard tested the manual controls of the Mercury capsule in space and manually fired the retrorockets that slowed the capsule enough to allow it to fall back to Earth. Gordon Cooper, the astronaut aboard the last Mercury flight, was forced to land his capsule manually when the automatic reentry system developed electrical problems.
As missions grew more complex, astronauts began to control more aspects of the mission. Cosmonauts and astronauts of the Soviet Voskhod and U.S. Gemini programs studied the effects of weightlessness, left the spacecraft in pressurized spacesuits to perform extravehicular activities (EVAs) or spacewalks, and guided their capsules close enough to other spacecraft to dock with them. During the Apollo program, astronauts spent days on the surface of the Moon exploring and performing experiments. Astronauts aboard the U.S. Skylab [[KW]] space station [[/KW]] and the Soviet Salyut and Mir stations began to spend months in space at a time.
Astronauts who fly aboard the space shuttle or stay aboard the International Space Station often spend months or years developing their missions. Astronauts have significant roles in planning and carrying out scientific experiments and performing tasks while in space. The U.S. National Aeronautics and Space Administration (NASA) designates space shuttle astronauts as pilots, mission specialists, and payload specialists. Every space shuttle mission includes at least two pilots and at least two mission specialists.
 
Astronaut at Work
Aboard the space shuttle Columbia, scientist-astronaut Franklin Chang-Diaz examines the contents of a student experiment. The experiment measured the effect of growing in space on auxin levels and starch grains in plant roots.
NASA/Science Source/Photo Researchers, Inc.

Pilots can have one of two jobs on a mission: They can be the mission commander or the mission pilot. Commanders work with controllers on the ground to make all critical decisions during the mission. Commanders also fly the shuttle in space and during landing and can take over from the space shuttle’s computers at any time. They also monitor the shuttle’s key systems—such as guidance, navigation, and flight control—throughout the mission. The mission pilot acts as a backup to the commander. The pilot has the same training as, but usually less experience than, the commander.
Mission specialists are scientists and engineers who deal with the specific experiments and equipment onboard for the mission. They must have detailed knowledge of shuttle systems and of the equipment and objectives associated with that mission. Their duties in orbit may include leaving the spacecraft for spacewalks, operating the space shuttle’s robot arm (called the remote manipulator system), deploying satellites, and operating onboard experiments. On every space shuttle flight, one mission specialist acts as flight engineer during launch and landing to support the pilot. Two mission specialists in each mission are assigned emergency spacewalk duties, just in case the mission requires an unexpected spacewalk.
 
Spacewalker and Manned Maneuvering Unit
Astronaut Bruce McCandless floats free above the [[KW]] earth [[/KW]] in a manned maneuvering unit (MMU) during a shuttle mission. McCandless helped design the MMU and was the first to fly one. The MMU is propelled by small nitrogen thrusters controlled by the astronaut’s hands. Because no umbilical cord attaches the astronaut to the spacecraft, it gives much greater mobility than was available to earlier spacewalkers.
NASA/Science Source/Photo Researchers, Inc.

Payload specialists serve on some [[KW]] space shuttle [[/KW]] missions. Payload specialists are not astronauts by profession, but receive months of space shuttle training before their mission. The science team for the mission selects its own payload specialists. Payload specialists work on specific experiments or equipment with which they have significant experience. Because payload specialists are more scientists or engineers than astronauts, they are able to provide greater expertise than a career astronaut could obtain in the 18 to 24 months before a mission. Often a mission specialist and a payload specialist will pair up during training and during the mission to create a team with extensive experience in both space shuttle and scientific systems.
Before the space shuttle Challenger exploded in 1986 (see Challenger Disaster), [[KW]] NASA [[/KW]] allowed a few people who were neither scientists nor astronauts aboard the space shuttle as payload specialists. These included U.S. senator Jake Garn and teacher Christa McAuliffe. After the Challenger explosion, NASA began to require that payload specialists have more space shuttle training and extensive expertise in the mission’s scientific objectives.
 
Astronauts on the Moon
Apollo missions 16 and 17 were the last Apollo missions to the moon. The astronauts devoted much of their time to collecting rock and soil samples. Both missions used a battery-powered rover so the astronauts could gather material from a wider area than previous missions.
Oxford Scientific Films

All crew members usually share in space housekeeping duties such as meal preparation, cleaning, and stowing gear. Between spaceflights, astronauts support other space shuttle missions through jobs in Mission Control or at the launch site, by advising teams that are planning future payloads and missions, or by helping test future experiments and equipment.
Every operation during a flight is important and interesting, but many might be boring to an observer. Much of an astronaut’s job is entering computer instructions, preparing samples, making measurements, recording data, fixing what breaks, and adjusting the checklist when something unexpected happens. Sometimes astronauts retrieve or repair satellites, rendezvous or dock with other spacecraft, and do important emergency repairs. The adaptability of the human crew is crucial to the success of missions in which unexpected things happen.