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Earth, our mother planet, is being attacked everyday by about 25 tons of dust & sand-sized particles. An asteroid, the size of a small car, hits Earths atmosphere about once in every year.

Fortunately she knows how to defend herself. When that small car-sized asteroid enters her atmosphere, she burns the asteroid up before the latter touches her surface. And so… So no damage is done.

But what exactly are asteroids? Asteroids are fragments from the formation of the Solar System some 4.6 billion years ago. Fortunately, most asteroids are found in the Asteroid Belt found between the planets Mars & Jupiter, the gas giant. OK. Scientists think that asteroids found in the belt can be as big as 940 km across.

Like everybody though, Earth can not cope with each & every one of the asteroids.

If an asteroid has managed not to be completely burned up while sprinting into Earths atmosphere, then ???? Scientists think that the collision would cause local damage to the surrounding area.

If that same asteroid however measures more than 1 km across when it touches Earths surface, disaster is on its way. Scientists believe that this impact could have worldwide effects. Man however is helping or trying to help our mother Earth.

Astronomers are now observing & tracking asteroids, which are at an average distance from Earth to Moon. By immediately tracking potential dangers & learning a lot more about their orbital paths, scientists have more time to study potentially threatening situations. Clear? In the next few years, NASA hopes to discover more than 90% of all Earths threatening objects larger than 1 km across.

But we have to stop these threatening asteroids from hitting Earth so as to save ourselves.

In some movies, we see a missile being launched straight towards a big asteroid. The latter then explodes & the film usually ends. But in reality, its not that simple. Did you ever think what might happen to the biggest remains of that big asteroid? Maybe it would go & enter Earths atmosphere or maybe not. If it does pass this first test, maybe it will cause big damages or maybe not. You’ll agree with me that man can not take such a risk.

An idea suggests that if a small asteroid is indeed intending to hit Earth, an engine is to be anchored in it… This engine is simply going to push the asteroid away.

Yet another strategy to put the asteroid out of the way is to attach solar sails to it… The gentle pressure of sun light on the sails will deflect the asteroid away from Earth.

Luckily an asteroid the size of a football field manages to hit the Earth only every thousand years or so but mind you I do not know when such an asteroid did hit Earth last.

K.A.Cassimally is the editor in chief of Astronomy Journal, a small publication of the RCPL Astronomy Club, Mauritius.

Here is the new website(to be launched in February 2004): http://www.rcplastronomyclub.zik.mu

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K.A.Cassimally

A celestial body orbiting another celestial body of larger size is a satellite. An artificial satellite is a manufactured object or vehicle intended to orbit the earth, the moon, or another celestial body. Since October 4th, 1957 humanity is capable of putting artificial satellites in orbit around the earth. The Russians were the first with Sputnik; a small satellite that orbited the earth for a couple of months & transmitted beeps for 21 days.

The USA launched its first satellite on January 31st, 1958. This satellite was named Explorer 1, & through the data transmitted back to earth by Explorer 1, scientists discovered the van Allen radiation belts, zones in space around the earth, & the planets Jupiter & Saturn, containing high-energy protons & electrons.

fifty years ago artificial satellites did not exist. OK. Since Sputnik more than 4800 satellites have been launched by governments & private companies around the world. Satellites are used for satellite TV of course, but there’re many more purposes for satellites.

Types of Satellites

The Moon is a satellite of the earth; the earth is a satellite of the sun. The first is called a moon, the second a planet. Man made (artificial) satellites orbit any celestial body & are always called a satellite, whether they orbit the earth, the moon, the sun or any other celestial body.

We use satellites for different purposes & all satellites can be placed in one of the following categories:

Communications Satellites

Distribution of television & audio signals, and telephone connections via satellite are done by Communications Satellites. These types of communications typically need a satellite in geostationary orbit. In 1964 the US Department of Defense launched the first satellite that was placed in geostationary orbit. This satellite was named Syncom 3.

Today geostationary satellites are used to provide voice, audio & video communications like satellite TV by Dish Network Satellite.

Navigation Satellites

These satellites were of enormous help to transportation companies, especially transportation over water & through the air. The US GPS satellites are in Low Earth Orbit (LEO) & can determine position with a precision of 1 cm (0.4 inch). However, that very precise positioning is available for military purposes only. For commercial use the precision is less accurate.

Navigation satellites are also used for distance measurements for instance between buildings.

Weather Satellites

Observing the earth is the task for weather satellites, and then especially what happens in the atmosphere. Different kinds of cameras, like infrared & normal cameras are used to observe either the same part of the earth, from a geostationary orbit, or more closely from polar orbits to get more detailed pictures. These low orbit weather satellites focus more on the study of the atmosphere than on the current weather it self.

Military Satellites

Very similar to weather satellites, military satellites are also used for observing the earth. Generally with higher resolution cameras & instead of normal communications equipment, they use encryption as well. Some times these types of satellites have very different types of orbits. For instance a very elliptical orbit which brings the satellite as far away from the earth as the moon & as close to the earth that it shortly enters the atmosphere, to get as close as possible to the earth surface without falling back to earth.

Probably many more tactics are used, but for obvious reasons, these are unknown.

Scientific Satellites

Observing the earth for scientific purposes is also very good possible with satellites. Making maps with low polar orbits satellites for instance, but also measuring the exact shape of the earth, geological research, etc can all benefit greatly from scientific satellites.

But scientific satellites are not just used for observing the earth. The research of space benefits also from scientific satellites. For instance the Hubble Satellite which actually is a enormous telescope that orbits the earth. Because the Hubble telescope doesn’t have to “see” through the atmosphere it can produce much clearer & detailed images than earth based telescopes.

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Gary Davis

Ever since the beginning of time, mankind has been fascinated with wonders of space. Before the mid-1900s, all mankind could do was gaze at the stars from Earth & wonder what it would be like to go into space. Man would look through telescopes & make theories on how the universe worked.

Even with growing knowledge in the field, it was not until 1957 when the first Earth orbiter, the Soviet’s Sputnik 1, was sent into space & placed in orbit at an altitude of 1,370 miles & weighed 184 pounds. Later in that year, the Soviets sent Sputnik 2 into space with a dog named Laika. Laika was the first animal to venture into space.

Then in 1985, the United States successfully sent their very own satellite into space. In 1960, the Soviets launched two dogs into space & successfully returned them to Earth. From this point started the space race. The space race was a challenge between the USSR & the United States to see who could land a man on the moon first.

In 1961, the first man in space was cosmonaut Yuri Gagarin who was in space for sixty minutes before returning to Earth in Vostok 1 & was sent by the USSR. Astronaut Shepard flew the first manned sub-orbital space-flight by the Americans. The first true American orbital flight was by John Glen & he stayed in space for five hours in Mercury 6 in 1962. Then in 1963, the USSR sent the first woman into space; her name was Valentina Tereshkova-Nikaleva. They also had the first person to take a space-walk in 1965. In 1968, the National Aeronautics & Space Administration or NASA tested the first Saturn 5 rocket, which would be used for the Apollo missions. The first manned Apollo missions & the first flight around the moon took place in 1968. Finally, on July 21, 1969, the United States placed the first man on the moon winning the space race.

Now, the future of space exploration depends on many factors. So… Some of these factors are as followed: how much technology advances, how political forces change rivalries as well as partnerships with other nations, and how important space exploration is to the general public. NASA is working on a single-stage-to-orbit (SSTO) vehicle, but until it’s until then, NASA plans to us the space shuttle fleet to the year 2012. It’s clear that mankind has devoted itself to the exploration of the unknown & that we’re committed to find new planets on which man can live & prosper. An interesting spacecraft is the X-33, which is a single stage orbiter. The X-33 will allow companies to put satellites in orbit for a cheaper cost.

Space travel does take its effect on humans though. Piloted space flights have to supply oxygen, food, & water for their occupants & even longer flights need to have a way to dispose of or recycle waste. The even longer flights, spacecrafts will eventually need to become mostly self-sufficient. The astronauts will have to exercise & since the astronauts will be weightless, the shuttle will need to provide more than just the core physical needs for the astronauts to stay healthy.

The weight of the craft is so important that it plays a crucial role in the amount of food supplied by the spacecraft. Most food provided to the astronauts is dehydrated, which is rehydrated by a device that is some what like a water gun, to save space as well as weight.

However, some foods are given in their conventional form such as fruits, candy, & bread. Water is usually provided by fuel cells that also provide electricity to the whole ship. The reaction between Hydrogen & oxygen gives the electricity & creates water as well. A small amount of water is also carried onboard in case of emergencies.

Space exploration has come a long way since the beginning. Mankind has gone to the moon & back, we have sent probes to the furthest reaches of our solar system, we have sent a robot to roam the Martian terrain, we have made spaceships that are reusable, and we can see other galaxies that are billions of light years away. Now we brainstorm on how to explore space even further. Man kind is destined to go to the far reaches of the universe & make contact with other life forms. Right. With all things considered, humans are not far from colonizing space.

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Ben Franklin

In 1952, the International Council of Scientific Unions (ICSU) announced the International Geophysical Year (IGY), a time span between July 1957 to December 1958. This period was to be filled with numerous scientific experiments & studies about Earth. It was in 1955 that the Soviet Union surprised the world by announcing the plan to orbit a satellite in the International Geophysical Year. As this was the time of great rivalry between the United States & the Soviet Union, US President Eisenhower promised that the United States would orbit a satellite in this period themselves. This was the start of the Space Race.

Both countries had missiles in development, Intercontinental Ballistic Missiles (ICBMs). Their mission was the same on both sides: To deliver a single nuclear warhead over an intercontinental distance. But as the Soviet warhead was much heavier than the US one, the Soviets developed, from the beginning on, a stronger rocket, which showed very useful later in history for use as a space launcher. In the United States, the satellite should have been orbited by an all-civil rocket, the Vanguard.

Sputnik 1 was launched by the Soviet Union on October 4, 1957. It was a shock for the western hemisphere, all forth the United States. Not only that the Soviets had orbited a satellite, it was the mass that shocked the governmental authorities. Though the Sputnik itself weighed only 84 kilograms, the third stage of the rocket orbited the Earth as well. And this stage alone weighed about 7.5 tonnes. Clear? In contrast, the US satellite, named like its launcher Vanguard, had a mass of only 1.36 kilograms & the rocket was more like a patchwork. Tauntingly said, the Americans put every kind of rocket together they could find. Not that surprising that the maiden launched failed only a few seconds after lift-off.

But in the progress of developing the first satellites, the United States slowly recognized their shortfall in rocket technology & allowed Wernher von Braun & his Army Ballistic Missile Agency (ABMA) to reinforce a military Intermediate Range Ballistic Missile (IRBM), the Redstone, with two additional stages, so that this launcher, now called Jupiter-C, was able to deliver a small payload into orbit. The first US satellite, Explorer 1, was successfully put into orbit on January 31, 1958. In the meantime, the Soviets had launched a dog onboard Sputnik 2, a satellite with a mass of 508 kilograms. But already in this very early phase, one difference showed up.

While the Soviets were able to put large payloads into orbit, their scientific payloads often suffered under the backlog in electronics & the kind of the academic landscape. Explorer 1, for example, although weighing only a bit more than a kilogram, gave valuable information about a radiation belt around the Earth, later called the Van-Allen Belt after the professor who developed the instrument onboard the satellite. In contrast the Soviets had problems to exchange data & information as the whole space program was highly classified.

It soon became clear for both sides, that space flight was a perfect environment to show their assumed technological supremacy over each other. Both thought that they could document the superiority of their respective administrations. That’s why both of them early envisaged a manned space flight. The Soviets approached their goal with a relatively simple solution. A sphere-shaped capsule with no possibility for the spaceman to control or steer the craft.

On the other side of the Earth, the Americans had two concepts under investigation. They had a very successful experimental flight program, the X-15. One option was to develop a next evolutionary step of this craft, the reusable like a plane X-20. First to be carried under a Mach-3 bomber, the B-70, up the atmosphere to fly ballistic flight profiles. Later the craft should have been fitted onto a Titan rocket in order to fly orbital missions. As the realisation of this program would have taken a long time, it was decided to initiate the “Man in Space Soonest” program, that later became the Mercury project. The X-20 was kept alive for a few years as an Air Force program but was then cancelled. One can only speculate how space flight would have developed if the United States had chosen a fully reusable craft from the beginning on.

After these initial competitions between the two Superpowers about the firsts, like first satellite, first man in space, first “space walk”, both states soon targeted a new major goal: the moon. Even though the Soviets denied until its decline in 1991 all the time that they had a moon program, the whole program is clear today. Both countries depended with their ambitious programs on large boosters: the Saturn V on the US side & the N-1 on the Soviet side. Today one can say, that the N-1 was the only major failure of the Soviet or today Russian space program (beside the point, that not a single Mars probe ever functioned as intended, if ever reaching Mars).

But it was a very serious duel. Both rivals took great risks in achieving their goals… And as no one has luck for all times, both had to mourn about first victims. Vladimir Komarov died on the first manned flight of a new capsule, the Soyuz 1. The United States lamented about the crew of Apollo 1, Ed White, Roger Chaffee & Virgil “Gus” Grissom.

But nonetheless the United States landed on the moon in 1969 & after a third failure in trying to launch their super-rocket N-1 the Soviets cancelled their moon program. But this was not the end of the Space Race. It seemed that the United States had won, but the Soviets had an ace in the hole. They switched from the exploration of the moon to a completely different goal: manned space stations. So… Salyut 1 was launched on April 19, 1971. The first crew that docked with the station, Soyuz 11, directly achieved a new endurance record of 23 days, the obviously new goal of the Space Race. And so… Sadly, the crew of Soyuz 11 died at re-entry due to an open valve.

As the United States launched their first space station, Skylab, in 1973, the Soviet Union already had Salyut 2 in orbit & gained a lot of experience in long time stays in microgravity & about operating space stations. But Salyut 2 was still a small station compared to Skylab & had much in common with the first one of its name. And so… So it was not very surprising that the first crew of Skylab set a new endurance record in 1973. After the United States stopped their Apollo-based flights with the Apollo-Soyuz-Test-Project (ASTP) in 1975 to wait for their new Space Transportation System or Space Shuttle, the Soviet Union continued their space station program with a steady pace. In regular intervals, new stations were orbited & each of them incorporated improvements & new features. Right. With Salyut 6, launched in 1977, the Soviets entered a new phase. This was the first station that had two docking ports, so it could be replenished by unmanned cargo transports as well as receiving guests on an additional Soyuz ferry.

The Space Race practically ended with the mothballing of Skylab but still both states walked somewhat side by side: both opened their spacecrafts to international guests. The Soviet Union started their Intercosmos program in 1978 with the first flight of a Czech cosmonaut, Vladimir Remek, the Space Shuttle saw the first non-American to fly in 1983, German Ulf Merbold. Even though during the first ½ of the 1980s the rivalry between both countries grew over again, the signs of a new Space Race were only a short flame up: Neither the United States with their space station Freedom, nor the Soviet Union with their Shuttle-craft Buran had the will or money to push these programs through.

With the fall of the Soviet Union in 1991, a new era was to become reality. US-built rockets like the Atlas flew with Russian-built engines. The Space Shuttle docked with the Mir space station & Americans stayed for 6 months onboard the station while Russian cosmonauts flew on the Shuttle. And today we have the International Space Station ISS.

But this was only the end of the first part: A new Space Race already waited on the horizon. To be more precise, not just one, but instead three Space Races would soon become reality.

Watch out for the next parts of the Space Race.

By: Klaus Schmidt

Klaus Schmidt writes about the developments in spaceflight at space-future.blogspot.com & The Space Fellowship.

Klaus Schmidt