Machines in Space

The earth is one of several satellites of the sun. Satellites are things that go around the sun or a planet at the same speed all the time. The earth's biggest satellite is the moon, but since

1957, when Russia launched the first man-made satellite, there have been hundreds of others sent up to do different jobs.

There are different kinds of man-made satellites in space. Military satellites have cameras which can see what is happening in other countries. These help countries defend themselves against surprise attacks. Communication machines, called Comsats, travel through space at the same speed that the earth turns so that they are always over the same place. Signals from one earth station are received and sent back down to another station thousands of miles from the first. Before Comsats, it was necessary to lay long expensive cables, which couldn't carry many messages. Comsats carry thousands of messages each minute.

Map makers are drawing much more accurate charts and maps because they have photos from survey satellites showing exactly where everything is, and weather forecasters have photos of all the clouds around the world. They can see when a storm is forming, and they can tell how long it will take to strike. Navigators on ships and airplanes can now find out exactly where they are by use of the Satnav system - even when it is cloudy or foggy and no stars are to be seen.

Laboratory satellites are usually the only ones that have people in them. The Russians have a lab that has been constantly occupied by scientists for many years. There are plans to build a very large satellite called a space station. Much of the knowledge about how to do this has been learned aboard American Shuttle labs which become satellites for a few days at a time and then return to the earth, so the labs can be changed and sent into space again to learn something

Someday, people may live their entire lives aboard satellites in space.(1627)

Apollo Astronauts. Land on the Moon.

The start of America's effort to get humans to the moon is often linked to President Kennedy's 1961 speech, which set this as a goal to achieve by the end of the decade. His speech boosted funding for NASA [National Aeronautics and Space Administration), but the journey to the moon really goes back to 1959, when NASA was just beginning.

NASA’s first space exploration program, named Mercury, was an urgent attempt 16 catch up to the Russians, who had already launched an orbiting satellite and put a dog into space. Mercury successfully put an American into earth orbit in 1961 for 24 hours. The next stage of the U.S. space program, called Gemini, advanced spacecraft design by engineering dockable components. The Apollo program followed, named for the Greek god of music, prophecy, medicine, light, and progress.

Apollo spacecraft were designed for travel to the moon. Improving on Gemini's component parts, Apollo spacecraft were made up of three modules. The command module could carry three astronauts. The service module held the engines, electric power generator, and oxygen and water stores.

The lunar module was itself a two-stage vehicle, designed to get the astronauts from the command module orbiting the moon to the moon's surface, and then to serve as their shelter while on the moon. Several test flights were accomplished, but on January 27, 1967 a fire in the command module on the launch pad killed all three drew members. A faulty hatch had prevented their escape. NASA took a step back from its hurried pace. The missions of Apollos 7, 8, 9, and 10 tested equipment in Earth and lunar orbit, but Apollo 11 was slated to land on the moon. It launched on Julyl6, 1969 at 9: 23 a.m.

Seventy-six hours later, it entered lunar orbit. There was a television camera on board the lunar module, so the entire world could see mission commander Neil Armstrong climb lightly dawn the ladder in the moon’s low gravity and could hear his slightly scratchy voice transmitted to Houston: ’’That’s one small step for a man; one giant leap for mankind.”(1741)

Date: 2015-01-29; view: 1160