ASTRONAUTS

Anyone who travels in space is called an astronaut. The Russians call their space travelers cosmonauts. Most astronauts stay in space for only a few days, but some remain there for months in permanently crewed space stations.

WHAT KINDS OF TASKS DO ASTRONAUTS PERFORM?

On missions into orbit, a commander and pilot fly the spacecraft. Mission specialists make observations and carry out experiments, and, if necessary, they perform EXTRAVEHICULAR ACTIVITIES (EVAs).

HOW DO ASTRONAUTS TRAIN FOR THEIR MISSIONS?

Pilots and commanders have flight training in jet planes and flight simulators. Mission specialists rehearse mission procedures and experiments. They may train for EVA submerged in water tanks, where conditions are similar to the weightlessness of space.

SUITED FOR SPACEWALKING

A spacesuit is a multilayer garment that provides an astronaut with pressurized oxygen and protection from the hazards of space—extreme heat and cold, radiation, and meteorite particles.

EXTRAVEHICULAR ACTIVITIES

Any work that astronauts perform outside a spacecraft is called extravehicular activity (EVA) or spacewalking. On EVA, astronauts wear protective spacesuits. Usually, they are attached to the spacecraft by a safety tether. Sometimes they move around freely, using a jet-propelled backpack, or MMU (manned maneuvering unit).

WHY DO ASTRONAUTS NEED TO LEAVE A SPACECRAFT?

One major job for spacewalking astronauts is to help rescue and repair satellites. Some shuttle astronauts carry out regular in-orbit servicing on the Hubble Space Telescope, replacing faulty or outdated equipment. Astronauts may also carry out space construction work. Lengthy EVAs are helping to assemble the International Space Station (ISS) from parts ferried into orbit by other vehicles.

Table 14. LANDMARK EVAs

DATEMISSIONASTRONAUTEVA
1965Voskhod 2Alexei Leonov1st spacewalk (10 min)
1969Apollo 11Neil Armstrong1st Moonwalk (2 hr 30 min)
2001ISSJim VossLongest spacewalk (8 hr 56 min)
Copyright © 2007 Dorling Kindersley