Less than four years after the launch of the first
satellite into space, Sputnik 1 in October 1957, human space travel began.
Since then, American astronauts have walked on the Moon, and Russian cosmonauts
have remained in space for more than a year at a time in space stations. Today
astronauts travel in both rockets and the SPACE SHUTTLE. In the
decades to come, astronauts are likely to return to the Moon to set up bases,
and even travel to Mars to explore the secrets of our neighbouring
planet.
The last Apollo space mission, Apollo 17, took place in December
1972. Eugene Cernan and Harrison H. Schmitt landed on the Moon’s
surface in a lunar module. In all, six Apollo spacecraft made successful
landings on the Moon.
Yuri Gagarin was first man to travel in space, on 12 April, 1961,
orbiting Earth once. The first American to orbit Earth, John Glenn, flew into
space on 20 February, 1962.
On 20 July, 1969, Apollo 11 made the first Moon landing. Neil
Armstrong and Buzz Aldrin walked on the Moon. Michael Collins
manned the command module.
After launch, all American manned space missions are controlled from
Mission Control at Houston, Texas. Controllers oversee all aspects of mission
operations, such as checking spacecraft engineering data, following in-flight
experiments, and communicating with the crew.
When it was first launched, on 12 April, 1981, the space
shuttle began a new era in space flight. Until then, all launch vehicles had
been expendable – they could be used only once. But the space shuttle is
re-usable – most parts can be used again. The shuttle is made up of twin
booster rockets, a winged orbiter which carries the crew, and an external fuel
tank.
Space Shuttle Endeavour is the most recent orbiter. It has
completed 17 flights since it was first launched in 1992. The winged orbiter
houses the crew and carries the payload (cargo). The crew fly the shuttle from
the upper flight deck and have their living quarters on the mid-deck. There are
three orbiters in use – Discovery, Atlantis, and Endeavour.
The space shuttle is piloted from a two-man cockpit in the front
of the orbiter’s upper deck. The crew are surrounded on all sides by
instruments and controls, and are seen here wearing orange launch and entry
suits (LES). The LES protects the astronaut in the event of a pressure leak in
the flight cabin. It also provides an emergency oxygen supply, a parachute,
life raft, emergency water supply, and full survival and rescue kit.
The shuttle operates from Complex 39 at the Kennedy Space Center
in Florida, USA. The different parts are put together in the huge Vehicle
Assembly Building, originally built to house the gigantic Saturn V Moon
rockets. The shuttle stack sits vertically on the launch pad on top of a mobile
launcher. It stands about 56 m (184 ft) high. During launch, the orbiter
discards first the twin boosters, then the external tank, before climbing into
orbit.
The orbiter’s main engines and the twin solid rocket
boosters (SRBs) all fire together at lift-off.
About 2 minutes after lift-off, the SRBs separate and parachute
back to Earth to be recovered from the sea.
About 6 minutes later, the external fuel tank is jettisoned. It
is not recovered, but burns up in the atmosphere.
Orbiter enters orbit, circling Earth about every 90 minutes. It
usually stays in orbit for about a week.
On its return, the orbiter re-enters the atmosphere. Its heat
shield glows as it is heated by friction.
Once in the atmosphere, the orbiter flies like a glider and
lands on an ordinary runway.
