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Speaking
Work in pairs and answer the questions:
Student A
a) What did you think when you read the headline?
b) What springs to mind when you hear the word ‘alien’?
c) Do you think governments should spend money on space exploration?
d) Do you think there is life on other planets?
e) What should scientists do if they find signs of life?
f) What three questions would you ask an alien?
g) Do you think there’d be any problems if aliens came to Earth?
h) What do you think the chances are of finding a planet similar to Earth?
i) What do you think the chances are of aliens looking like us?
j) If no planets are found, is the telescope a waste of money?
Student B
a) Did you like listening to this article?
b) What’s more important, this $600-million telescope or feeding the poor?
c) Have you ever set sail on a great journey?
d) What kind of people do you think space scientists are?
e) What other historical landmarks in space exploration do you know of?
f) How would we change if the telescope found hundreds of Earths?
g) What’s the most important journey you’ve been on?
h) What questions do you ask when you look up at the sky?
i) Do you care whether or not we are alone?
j) What questions would you like to ask NASA’s space science boss Ed Weiler?
Unit 9
Space vehicles
Rocket is a vehicle equipped with a jet engine and used for space travel. Rocket consists of:
Launch escape system: tower that enables the astronauts to retreat in case of danger.
Lunar module: means of transport for traveling on or around the moon.
Liquid hydrogen: part of the rocket containing reserves of liquid hydrogen.
J-3 engine: part of the third stage that detaches it from the second stage.
J-2 engine: part of the second stage that detaches it from the first stage.
Liquid oxygen: part of the rocket that contains reserves of liquid oxygen for use as engine fuel.
Kerosene: part of the rocket that contains reserves of kerosene for use as engine fuel.
Stabilizing fin: part of the rocket that keeps it steady during takeoff.
Nozzle: part of the rocket through which flowing fluid enables it to gain speed.
F-1 engine: part of the rocket that enable it to take off.
First stage: part of the rocket closest to the ground during takeoff.
Inter-stage: part of the rocket connecting the first and the second stages.
Second stage: second part of the rocket from the ground.
Third stage: part of the rocket that carries the payload.
Payload: that which is to be in space.
Text 9A
Rockets
The invention of rockets is linked inextricably with the invention of 'black powder'. Most historians of technology credit the Chinese with its discovery. They base their belief on studies of Chinese writings or on the notebooks of early Europeans who settled in or made long visits to China to study its history and civilization. It is probable that, sometime in the tenth century, black powder was first compounded from its basic ingredients of saltpetre, charcoal and sulphur. But this does not mean that it was immediately used to propel rockets. By the thirteenth century, powder-propelled fire arrows had become rather common. The Chinese relied on this type of technological development to produce incendiary projectiles of many sorts, explosive grenades and possibly cannons to repel their enemies. One such weapon was the 'basket of fire' or, as directly translated from Chinese, the 'arrows like flying leopards'. The 0.7 meter-long arrows, each with a long tube of gunpowder attached near the point of each arrow, could be fired from a long, octagonal-shaped basket at the same time and had a range of 400 paces. Another weapon was the 'arrow as a flying sabre', which could be fired from crossbows. The rocket, placed in a similar position to other rocket-propelled arrows, was designed to increase the range. A small iron weight was attached to the 1.5m bamboo shaft, just below the feathers, to increase the arrow's stability by moving the centre of gravity to a position below the rocket. At a similar time, the Arabs had developed the 'egg which moves and burns'. This 'egg' was apparently full of gunpowder and stabilized by a 1.5m tail. It was fired using two rockets attached to either side of this tail.
It was not until the eighteenth century that Europe became seriously interested in the possibilities of using the rocket itself as a weapon of war and not just to propel other weapons. Prior to this, rockets were used only in pyrotechnic displays. The incentive for the more aggressive use of rockets came not from within the European continent but from far-away India, whose leaders had built up a corps of rocketeers and used rockets successfully against the British in the late eighteenth century. The Indian rockets used against the British were described by a British Captain serving in India as ‘an iron envelope about 200 millimeters long and 40 millimeters in diameter with sharp points at the top and a 3m-long bamboo guiding stick’. In the early nineteenth century the British began to experiment with incendiary barrage rockets. The British rocket differed from the Indian version in that it was completely encased in a stout, iron cylinder, terminating in a conical head, measuring one meter in diameter and having a stick almost five meters long and constructed in such a way that it could be firmly attached to the body of the rocket. The Americans developed a rocket, complete with its own launcher, to use against the Mexicans in the mid-nineteenth century. A long cylindrical tube was propped up by two sticks and fastened to the top of the launcher, thereby allowing the rockets to be inserted and lit from the other end. However, the results were sometimes not that impressive as the behaviour of the rockets in flight was less than predictable.
Match each item with the group which first invented or used them.
Write the correct letter A-E in boxes 1-4 on your answer sheet.
NB You may use any letter more than once.
1)black powder
2) rocket-propelled arrows for fighting
3) rockets as war weapons
4) the rocket launcher
First invented or used by
A)the Chinese
B)the Indians
C) the British
D) the Arabs
E)the Americans
Text 9B
Rockets for satellite communication
The world needs a telecommunications system which could give constant field strength at all times over the whole earth. Although it is possible to provide telephone links between any two points on earth, the ionosphere can make long distance communication difficult.
A rocket flying at 8 km/sec outside the earth's atmosphere would stay in orbit. It would be like a second moon, going round the earth without using power. If the rocket were in orbit 42,000 km above the earth, it would circle the earth once every 24 hours. It would stay above the same spot on the earth.
It would be possible to build a space station in such an orbit by carrying up materials in rockets. The station could be provided with transmitting and receiving equipment, and could act as a repeater to relay transmissions between any two points on the hemisphere beneath.
For a world service at least three stations would be needed, placed at equal distances around the earth. This is the only way to transmit around the whole world, using beams in an unlimited number of channels. The station would have very low power needs, and even if it were expensive at first the system would be much cheaper to run than present ones.
The first manmade satellite was launched on 4 October 1957. Five years later the Telstar, working in a low altitude orbit, made possible live broadcasts between North America and: Europe. The transmissions lasted for about 24 minutes at a time, but the satellite had the capacity for about sixty telephone circuits or a very limited TV channel.
Intelsat I had only 240 telephone channels, but now satellites like Intelsat V relay 75% of international telephone calls. New satellites have high capacity, long life, and can be used for telephone, television or computer data transmissions. Intelsat V has 12,000 circuits for all types of telecommunications.
Transmissions from a satellite can give global or spot beam coverage, but they are received by all earth stations in sight of the satellite. Each station selects the channels or carriers which are addressed to it. In the same way, all stations in sight of a satellite can use it simultaneously, and this is known as multiple access.
Earth stations must be capable of detecting very low level signals. Their parabolic antennas, which track the satellite automatically, feed the signal to a low noise first stage amplifier, which may be followed by a second stage travelling wave tube amplifier. The earth station transmitting equipment is very powerful, emitting signals at up to 10 kW. In some cases it is possible to control the satellite transponders and antennas from an earth station. This process is known as telecommanding.
INTELSAT was formed in 1964 to operate and maintain the global satellite communications system. The agency designs and builds satellites, and organizes their launching.
NASA, the U.S. space organization, is the main agency in the world for launching satellites. NASA’s two and three stage Titan rockets safely launched all ten Gemini manned spacecraft, as well as numerous satellites.
E.S.A., the European space agency, has produced the Ariane launch vehicle as a rival to Titan. For a 1.2 tone geostationary satellite an Ariane launch costs $30 million, compared to $75 million by Titan. However, although it is more costly, Titan is also more reliable with 119 successful launches out of 122.
The Ariane consists of three stages, each of which is a pair of fuel tanks with one or more rocket engines. The fuel from the two tanks burns when mixed in the engine. The large first stage lifts, the vehicle through the atmosphere, and when the fuel tanks are empty the section falls away, igniting the second stage. The process is repeated by the second stage, then the third stage, which carries a computer and directional equipment in its front end, and manoeuvres the satellite into position
Expendable launch vehicles such as Titan and Ariane now face strong competition from NASA’s new generation of re-usable "Space Shuttle" launch vehicles. Although the cost of a shuttle is as high as a billion dollars, the airplane like spacecraft is designed to go into orbit repeatedly, thus reducing the cost of launching a satellite to around $16 million.
The space shuttle is launched with the aid of two booster rockets and an external fuel tank. When the boosters are no longer needed they fall to earth by parachute, to be picked up from the sea and used again. Later the fuel tank is released, but this is not recovered. Once In orbit, the orbiter uses its own engines to manoeuvre. After the mission the shuttle re-enters the earth's atmosphere and lands on a runway in the same way as an aircraft.
Choose the correct answer:
1) Which two of the following subjects do you think the author deals with in this text.
a) To build space stations.
b) Use of rockets for launching satellites.
c) Description of the Ariane and the Titan.
d) A world service telecommunications system.
e) Role of satellites in modern communications.
Answer these questions:
1) Is it possible to have today worldwide communications? Why/why not.
2) How are satellites put into orbit?
3) Why does the ionosphere make long distance communication difficult?
4) To what does the author compare a rocket orbiting without power?
5) How are space stations built in an orbit?
6) What is the function of a repeater?
7) Why would satellite systems be cheaper to run?
8) What are the main characteristics of new satellites?
9) Which earth stations receive transmissions?
10)What is the name of the International Satellite Communication Organization?
11)What are the names of the American and European Space Organizations?
12)Which is the cheapest way to launch a satellite? Why?
13)Which is the most expensive and the most reliable vehicle?
14)How frequently can a space shuttle be used?
True or False:
Decide whether the following statements are true or false by referring to the information in the text. Then make the necessary changes so that the false statements, become true.
1) A space station acts as a repeater.
2) For a world service only two stations are needed.
3) The Telstar was launched in 1957.
4) Satellites are used only for T.V. and telephone transmissions.
5) Earth stations can control satellites.
6) INTELSAT was formed in 1964 to send monkeys to the moon.
7) INTELSAT designs and builds satellites, and organizes their launching.
8) After the mission the shuttle desintegrates.
Find and give the Information:
1) Distance from the earth needed by a rocket to circle it once every 24 hours.
2) The year in which the first telecommunications satellite was launched.
3) The duration of a Telstar transmission.
4) The capacity of Intelsat I.
5) The percentage of international telephone traffic relayed by Intelsat V.
Locating Information
Find the passages in the text where the following ideas are expressed. Give the line references.
1) The ionosphere poses problems to communications.
2) To cover the whole world several stations are needed.
3) The first satellites had a very limited capacity compared to the new ones.
4) The signals sent off by the satellite are received by some earth stations.
5) Not all rockets cost the same.
6) One type pf launching vehicle can be used more than once.
Content review.
Find words with this meaning in the text.
a) Rocket used to give initial speed to a missile, after which it drops and leaves the missile to continue under its own power.
b) The planet on which we live.
d) Object for relaying back to the earth telephone messages, radio o TV signals.
e) Band of frequencies within which signals from a transmitter must be kept to prevent interference.
f) Outline from which something will be made.
Replacing terms.
Choose a word or phrase from the text to replace the underlined word.
a) To provide a link between two locations.
b) The ionosphere can produce difficulties in telecommunications.
c) Some satellites orbit the earth once every 24 hours,
d) A satellite could relay transmmissions to one half of the earth.
e) Earth stations are able to detect very low level signals.
f) The Ariane is composed of three stages.
Text summary.
Refer back to the text and choose the six most important points from this list in order to get a summary:
1) Intelsat I had only 240 telephone channels.
2) The first manmade satellite was launched in October 4, 1957.
3) At least three stations are needed for a world service.
4) The world needs a telecommunications system.
5) The shuttle system reduces the cost of launching a satellite.
6) It is possible to control the satellites from an earth station.
7) INTELSAT organizes satellite launching.
8) Space stations can be built in an orbit.
9) The use of satellites in today's world communications is a must.
10) Rockets are used for putting the communications satellites into orbit.
Listening
“What goes up must come down”
Listen to the text and complete sentences with numbers:
| 12,000 40,000 100 9.8 2Ң 100 26 2800 3,000 |
1) The bullet starts going up really fast. If it's a good rifle it might be doing about ___kilometres an hour.
2) You probably studied this in school: falling objects accelerate at ___ metres per second and things going up decelerate at the same rate.
3) If you try doing a rapid calculation you can quickly see that the bullet will not get into space, which begins at a height of about ___ kilometres.
4) The cannon ball had to reach a speed of ___ yards per second.
5) The modern figure, 11,100 m/s or about ___ kilometres an hour, is called "escape velocity".
6) The only way to fly to a height of ___ kilometres is with an engine that will keep your craft moving upwards after it has left the ground.