Senior Science
9.9 SPACE
Section 5
EXPLORING
SPACE:
Space Stations
and other
Technologies
Section 5 Space Stations and Probes
Space stations and probes provide information about our solar system, galaxy
and deep space
9.9.5.a
Discuss requirements that would be necessary to sustain human life for
months or even years on a space station
9.9.5.b
Identify the space stations already used in space
9.9.5.c
Outline how information is transmitted between Earth and the space
stations
9.9.5.d
Describe and account for the advantages of building optical telescopes on
high mountains
9.9.5.e
Identify the type of information gathered about space by
–
Hubble Telescope
–
Very long baseline interferometry (VLBA)
–
Highly Advanced Laboratory for Communications &
Astronomy (HALCA) satellite working with ground-based
satellites (GBS)
9.9.5.f
Discuss the value of Search for Extraterrestrial Intelligence (SETI) and
Optical Search for Extraterrestrial Intelligence (OSETI) projects to identify
life and advanced civilisations in the universe
9.9.5.i
Gather and analyse information from secondary sources to present an
overview of the roles of the Voyager 1 and 2 space probes and how our
understanding of the solar system and universe was furthered by these
space missions
9.9.5.ii
Gather, process and present information from secondary sources to trace
the developments in technology that have enabled us to identify the
different components in the night sky
9.9.5.iii
Gather and process information from secondary sources to identify the
methods employed over time to collect information about our solar system
and beyond
9.9.5.iv
Gather and process information from secondary sources to trace
Australia’s involvement in space exploration
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9.9.5.a
Discuss requirements that would be necessary to sustain human life for
months or even years on a space station
LIVING ON A SPACE STATION
Introduction
When people orbit the earth, they are living in space. Space has no air and is crisscrossed by dangerous radiation and particles of matter. There are large changes in
temperature. Also, astronauts have no sensation of gravity ie they are weightless.
Astronauts can only survive in space if they are protected from such dangers.
For astronauts to stay healthy in space, their body needs must also be met. These
needs include breathing, eating and drinking, elimination of body wastes, sleeping,
exercise and recreation.
The spacecraft
During flight, astronauts are protected from the danger of micrometeoroids (very
small particles of space dust) in various ways. These are potentially dangerous as the
holes could cause the spacecraft to lose pressure. The hull of a spacecraft has
multiple layers of very tough and strong materials (such as nylon and Teflon).
All spacecraft have a heat-control system to withstand the extreme high and low
temperatures of space. The side facing the sun can get extremely hot. The side
facing away from the sun can get extremely cold. The heat-control system keeps the
inside of the craft at comfortable temperatures. A coated felt material provides
insulation against low temperatures.
Floating objects in the spacecraft can also be a problem. The large objects can be
easily noticed and removed. The many small bits can easily go unnoticed - examples
include a drop of water, a piece of hair or dust from careless cleaners. Very sensitive
equipment can be damaged by these floaters. Such problems can be overcome by
cleanliness, care and equipment design.
Notes Questions
1. Name three dangers associated with being in space
2. Name three bodily needs of astronauts that must be met on space missions.
3. Explain why micrometeoroids are dangerous to space craft.
4. Outline the problem associated with floating objects in the spacecraft.
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Needs of Astronauts
A manned spacecraft is equipped with life-support systems designed to meet all the
body needs of the crew. Their purpose is to keep astronauts healthy.
Air Supply: There is no air in space. Astronauts need to take a supply of air with
them on the spacecraft. The system that supplies air also purifies the air. It controls
the amount of moisture, removes carbon dioxide and cabin smells. This is important
since foul air can make astronauts sick, and can irritate their eyes.
Eating and Drinking:
The food on a space flight must be nutritious, easy to eat
and easy to store. Food comes in a variety of forms - natural (crackers), dehydrated
food (dried apricots) and canned food (tuna fish, canned fruit in heavy syrup). Food will
need to be grown on the spacecraft for long trips.
Elimination of body wastes: Because of weightlessness, toilets on spacecraft are
equipped with seat belts, footholds, and handholds to keep an astronaut in place.
Since there is no gravity to pull waste down into the toilet, crewmembers use an air
suction device. Faeces (solid waste) is also pulled by airflow to a storage tank where it
is dried. The air used for suction passes through a filter to remove odour and bacteria.
Sleeping:
An astronaut sleeps in a `standing position' in a sleeping bag attached to
the wall of a sleeping compartment. Elastic bands keep the sleeper in place.
Exercise:
Exercise is important for astronauts. The heart, and muscles weaken
because the body does less work due of weightlessness. The bones also lose calcium
and become more brittle. Astronauts need to exercise for at least 2 hours a day. This
keeps them healthy and mentally alert.
Leisure:
As space flights became longer astronauts might get bored. To break up
the monotony and prevent boredom thought had to be given to recreation. Music,
reading, chess and checkers provide astronauts with activities for leisure. A favourite
leisure-time activity has always been watching the view of the Earth through the viewing
window. Conversations with families using a two-way television hook-up also reduce
homesickness.
Sickness in Space:
About half of all astronauts become dizzy and sick from
working under weightless conditions. This occurs especially in the first few days of
flight. Astronauts using anti-motion drugs/medicine overcome this.
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Notes Questions
5. Yuri Gugarin was the first man in space (1961). He was in space for just 110
minutes. The spacecraft was equipped with life-support systems designed to
meet all his body needs. Also he needed to be protected from the hazards of
space and the dangers involved in getting there.
a]
Name two body needs that had to be met for Yuri?
b]
Name two dangers involved in space travel.
6. In space, crew members shave with an electric razor which has a special nozzle to
vacuum the tiny shaved bits of whisker. Without this vacuum, these tiny bits of
hair would fly around the cabin and could work their way into small openings in
vital equipment. Why is this a problem?
7. a] You eat normal food in space, but space food must be sticky to stay on a
spoon or fork. Why?
b] The food is eaten from special packages on a tray, which clips onto a table.
Knives, forks and spoons are attached to the tray by Velcro.
i]
Why are the clips and Velcro needed?
ii]
Why do astronauts eat slowly and carefully?
c] Some food is dried and needs hot or cold water to be added. What is the
reason for having dried food?
8. In very long space trips (to Mars - at least 4 years) astronauts will not be able to take
their supplies of food and oxygen. In 1990 in Arizona in the USA, a 200 000 cubic
structure called Biosphere II was built. It was designed to be self-sustaining. It
would supply eight people with food and oxygen while the plants, which supplied the
food, recycled the wastes.
a] What is meant by self-sustaining?
b] Name two wastes that need to be recycled.
c] How is this structure useful for space research?
d] List 3 requirements for Biosphere to be self-supporting.
Useful Websites http://edweb.tusd.k12.az.us/rmyers/mars.htm
http://www.users.globalnet.co.uk/~smithi/mars/biosphere2.htm
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9. Taking a shower in space is difficult. Cosmonauts take quite a while to shower.
To get some idea of the difficulties involved lie down with your head facing the spray.
If you had to describe to a person how a cosmonaut showers you could use the
following ten points. Unfortunately, the points are not in the correct order. Reorganise these points into a sensible order.
i]
ii]
iii]
iv]
v]
vi]
vii]
viii]
ix]
x]
When the water is turned off, a blast of air forces air out of the cylinder.
They use a plain cloth to rinse.
The cylinder has a waterproof seal.
Finally, the inside walls of the cylinder must be wiped dry.
Water is sprayed from both ends of the cylinder.
The shower consists of an elastic cylinder with caps at both ends
Cosmonauts use a soap-filled cloth to wash.
The nose is clipped to keep water out [water doesn't flow down in space].
Rubber slippers fastened to the floor keep the cosmonaut from floating up.
The cosmonaut inserts a hose into his or her mouth to breathe.
Once you have reorganised the information, answer the following questions.
a] What are the three ways the cosmonaut reduces the chance of water
escaping out of the cylinder?
b] What would happen if the cosmonaut tried to shower without the hose to
breathe or using the nose clip?
c] Give one reason why the cosmonauts must take such precautions.
10. The photograph of the Earth was taken from
the Apollo 17 Spacecraft.
This view
resulted in the idea of SPACESHIP EARTH.
a] Explain why it is possible to talk
about earth as a SPACESHIP.
b] Is spaceship earth self-sustaining?
c] Are the `astronauts' on spaceship
earth careful about looking after their
spaceship? Give two reasons for
your answer.
11. Neil Armstrong was the first man to walk on the moon. To protect him from the lunar
environment he wore an EMU (Extravehicular Mobile Unit). This spacesuit has a
life-support system.
a] Name 3 dangers of space faced by Neil Armstrong.
b] Describe how the EMU protects an astronaut from two of these dangers.
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SPECIFIC ISSUES RELATED TO LIVING IN SPACE
What to do
Discuss the statements and decide if they are true or false.
True or false
a.
b.
c.
d.
e.
f.
g.
h.
i.
j.
k.
l.
m.
n.
o.
p.
q.
r.
s.
t.
u.
There are no problems resulting from exercising in space.
The body takes time to “learn to adjust” to living in space.
The body changes that occur in space can cause big problems back on earth.
Broken bones heal in space.
Solutions have been found to treat most kinds of illness in space.
Exercise solves the problem of bone loss for long space flights.
Polyethylene shields will protect astronauts from radiation in space.
Only short people can be astronauts because of the confined spaces.
There are many people who would not become depressed on long spaceflights.
Some people would go mad cooped up on a spacecraft.
Body odour is not a problem when living in space
Storage of food and oxygen is an important issue on a long space flight.
A nose plug would be needed to shower in space.
In a micro-gravity environment fluid collects in the upper body.
An ordinary electric drill is used in space without modification.
To cut hair in space you need to cut and vacuum up clippings at the same time.
Most meals on a space station would be eaten using a straw.
Eating in space would be done more carefully than eating on the earth.
Fixing damaged equipment could be a problem on a long space flight.
Astronauts would have very little to do on a space station.
The correct concentration and pressure of oxygen, nitrogen and carbon dioxide
needs to be monitored and controlled.
Floating sweat
When astronauts exercise in a micro-gravity environment, sweat doesn’t
drip off their bodies. Rather, it becomes a puddle that “hangs around”. Immediately after
exercise, astronauts must catch the flying puddle and towel it up before it flies off and causes
problems in the spacecraft.
Fluid build-up
In a micro-gravity environment, fluid collects in the upper
body; neck veins bulge, faces puff up and legs shrink. The heart and other organs
enlarge a bit. Sensing too much fluid, the body removes excess fluid, and with it
calcium and blood plasma. The production of red blood cells decreases (anaemia).
Tools
Tools used in a space craft need to be modified or designed to operate in
micro-gravity; eg a hammer that does not recoil like an ordinary hammer would.
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Disorientation
Space farers usually become disorientated. In micro-gravity there is no
up or down. The inner ear sends confusing data to the brain, while eyes play tricks with
visual illusions. The sensory mix-up brings temporary space sickness.
To create a sense of up and down visual cues are used. Chairs, tables and most equipment
are located on the “floor”. The “ceiling” is painted white. Colour is also used to help
concentration – green for the work area and yellow for the living area
Body problems Astronaut David A Wolf, who spent 4½ months in Mir, identified
how weak he was on landing – “ I had lost 40% of my muscle mass, 12% of my bone,
and 23 pounds”. Wolf’s space adapted balance system, dealing once again with
gravity, gave him trouble-turning corners and had him “running into doors”. He also
recalled how “It took six months to feel strong again, a year to get the bone mass
back, and two tears to get the details of my life together”
The question of
astronaut health is of grave concern. It is not even known if a broken bone will heal
in space.
Bone problems Even with exercise, no astronaut in space for a long time has
returned without some bone loss. The time needed to replace bone loss varies greatly
between individuals. Two of the American Mir astronauts who were in space longer
than four months had bone deficits after two years. Others recovered within six
months.
Scientists believe that bone loss during long space flights will level off after a while.
Paraplegics have bone losses that level off at around 40%, but this is unknown for
long-term space astronauts. Bone loss greatly increases the risk of fractures. The
other problem is that the loss of bone density is not uniform – large deficits could
occur in the heels or hips.
Radiation Beyond the atmosphere shield, the astronaut is exposed to solar and cosmic
radiation. What is the cancer risk? At this time experts do not know the answer. The sun
flings billions of tonnes of charged particles into space. The Earth’s magnetic field protects
us from this radiation. NASA officials believe that astronauts can be protected from such
solar radiation by using a polyethylene shield that will absorb the radiation.
Cosmic radiation is a more serious threat. It has too much energy and speed for shielding.
This radiation will pass through the ship’s hull and the body causing equipment failures
and problems with body tissue. For long-term space travel understanding the effect on
biological processes is a high priority.
Mind problems Confined in a spacecraft roughly the size of two motel rooms, how will
astronauts get along with each other? The lack of living space could trigger depression and
irritability in cooped-up crewmembers. Loneliness is another psychological problem. Cultural
differences are also an issue. Separate cabins allow privacy. Also, the lives of astronauts
depend on the proper functioning of many complex systems – causing pressure due to living
in a potential tomb.
Since every centimetre counts, only a treadmill and stationary bicycle are compact enough
for the crew’s required exercise. Leisure pursuits are restricted to sedate activities – reading,
talking to family on earth, and listening to music. Competitive games are seldom allowed,
since conflict must be avoided in such cramped surroundings.
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9.9.5.b
Identify the space stations already used in space
THE FIRST SPACE STATIONS
Once the US landed a man on the moon the main focus of putting people in space
shifted to the development of earth-orbiting space stations
The Soviet Union was the first to put a Space Station into orbit. Salyut 1(“salute”)
was launched on April 19, 1971. In all, 7 Salyut space stations were launched. In
1984 a new space endurance record was set aboard Salyut 7 – 237 days in space.
Salyut 7 was last occupied in March 1986, and fell back to the Earth in 1991.
The US Skylab was launched on May 14, 1973. Three crews inhabited Skylab for a
total of 171 days. Hundreds of experiments were performed. The last crew left the
Skylab in February 1974. In 1979, Skylab fell back to Earth.
The Soviet Mir (“peace”) space station was launched in February 1986. Its orbital
altitude ranged from 300 to 400 kilometres above the Earth’s surface. Mir remained
in orbit for 15 years. It has recently returned to the Earth. Most of the station burned
up on re-entry – parts that did not burn up landed harmlessly in the Pacific Ocean.
The International Space Station (ISS) is the largest and most complex international
scientific project in history. When it is complete before the end of the first decade of
twenty first century, the station will represent a project of unprecedented scale. Led
by the United States, the International Space Station draws upon the scientific and
technological resources of 16 nations: Canada, Japan, Russia, 11 nations of the
European Space Agency and Brazil. It is four times bigger than Mir was.
The station will be in an orbit with an altitude of 400 kilometres with an inclination of
51.6 degrees. This orbit allows the station to be reached by the launch vehicles of all
the international partners for the delivery of crews and supplies. The orbit also
provides excellent Earth observations with coverage of 85 percent of the globe and
over flight of 95 percent of the population.
Notes Questions
12. Name all the space stations that have been built.
13. How high up do the space stations orbit?
14. Which is the biggest space station?
15. How many operational space stations are there presently in orbit?
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9.9.5.c
Outline how information is transmitted between Earth and the space
stations
COMMUNICATING WITH SPACE STATIONS
Information about a spacecraft’s precise location, speed, and status is called
telemetry. Maintaining contact between a spacecraft and the ground is a major task.
Networks of communications and tracking stations have been set up around the
world. They maintain contact with crew, send up commands and computer
programs, and receive data from spacecraft.
One system is called the deep space network. It comprises three powerful antennas,
each 69.9 metres in diameter, positioned around the world at Goldstone, California;
Madrid, Spain; and Canberra, Australia. Together they send and receive data from
both piloted spacecraft and planetary probes.
These large antennas are designed to pick up low frequencies. They are useful in
detecting the weak signals from satellites, and from space probes travelling into the
distant reaches of the solar system. The antennas of the network are positioned
around the globe in such a way to minimise the “blank” periods (ie when a satellite is
out of range).
The system used by NASA to communicate with the International Space Station
provides a variety of communication channels. It is comprised of three subsystems:
 The Ku-band subsystem for transmission of video and high speed data to earth.
 The S-band subsystem for transmission of two-way voice commands to the
space station and telemetry from the space station and
 The External Video Subsystem.
Notes Questions
16. What is the purpose of the Deep Space Network?
17. Think
Explain why the Deep Space Network has antennas positioned in
California, Spain and Australia?
18. Revision What band of electromagnetic wave does the Ku band belong to?
19. Revision What is the frequency of the S-band subsystem?
20. Copy and complete the
diagram showing a signal
being beamed up to and
down from a satellite.
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9.9.5.f
Discuss the value of Search for Extraterrestrial Intelligence (SETI) and
Optical Search for Extraterrestrial Intelligence (OSETI) projects to identify
life and advanced civilisations in the universe
The Value of SETI
Before beginning research about SETI complete the following questionnaire.
Strongly
Points related to the value of SETI
Agree
EI = Extraterrestrial Intelligence 1
2
Strongly
Disagree
3
4
5
Detecting evidence of Extraterrestrial Intelligence is difficult
SETI is a waste of money
Knowing EI would change life on earth
It is better to spend money on the earth’s needy than SETI
Pure research is an important for everybody in society
SETI produced improvements in radio receiving systems
SETI has increased international cooperation by scientists
It is important for scientists to ask questions about SETI
People tend to confuse SETI with UFO hunting
The idea of SETI will attract some people to science
SETI involves good scientific practise
The potential of SETI has important implications for humans
The human imagination drives people to aim for something
new, to go further. Some people will always seek new
challenges, new adventures: SETI is just one example.
SETI is an example of pure scientific research
SETI has produced no benefits to society to date.
Research money would be better spent on more practical
projects, than on SETI.
The more research that’s done in any area of science, the
better off everyone is going to be. The more that’s done in
physics, the better off a cardiologist is.
There is no better investment for a society than research.
The detection of a message from an alien civilisation would be one of the greatest
events in human history. Such a message could dramatically change the course of
civilisation, whether it were to share scientific information or bring about some sort of
social or humanistic enlightenment. Mindful of these profound implications, scientists
push ahead with the search for extraterrestrial communication.
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Research Activity
SETI & OSETI
SETI & OSETI
Discuss the value of Search for Extraterrestrial Intelligence
(SETI) and Optical Search for Extraterrestrial Intelligence (OSETI) projects to identify
life and advanced civilisations in the universe
[6 marks]
Answer the question using the following scaffold (table) for at least three issues.
Issue 1
Points for
Points against
Information Source
Go to the Google search engine
Click on the Groups box
Google
Web
Images
Groups
Directory
News
Advanced search
Preferences
Language Tools
Google search
I’m feeling lucky
Then type in SETI or OSETI and complete your search
Identify relevant information
The information contains useful information for the discussion
Marking Criteria – for each system
Outline SETI and OSETI
Identify at least three issues related to the value of such programs
Provide significant points for and/or against each issue
Outline SETI and OSETI
Identify at least two issues related to the value of such programs
Provide points for and/or against each issue
Outline SETI and OSETI
Identify at issues related to such programs but not the value of such
programs
Provide points for and/or against the issues
© P Wilkinson 2002-04
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Marks
5-6
3-4
1-2
9.9.5.i
Gather and analyse information from secondary sources to present an
overview of the roles of the Voyager 1 and 2 space probes and how our
understanding of the solar system and universe was furthered by these
space missions
Research Activity
Voyager Missions
The task
[6 marks]
Gather and analyse information from secondary sources
 To present an overview of the roles of the Voyager 1 and 2 space probes and
 How our understanding of the solar system and universe was furthered by these
space missions
What to do
Write an information report of 200 words outlining the journeys of the space probes
Voyager 1 and 2.
The report should contain
 A map showing where each probe went.
 An outline of the journey of each probe.
 Identify some discoveries made by each probe.
 Describe how our understanding of the solar system was furthered by these
missions.
Marks
Marking Criteria
Outlines each voyager mission
Draws a map of the path followed by each voyager spacecraft
Identifies at least two discoveries by each probe
Provides (in own words) at least two features of increased understanding
of the solar system
Outlines each voyager mission and / or with map
Identifies at least two discoveries by each probe
Provides one feature of increased understanding
Outlines each voyager mission and / or with map and / or
Identifies discoveries by probes
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5-6
3–4
1–2
9.9.5.ii
Gather, process and present information from secondary sources to trace
the developments in technology that have enabled us to identify the
different components in the night sky
9.9.5.iii
Gather and process information from secondary sources to identify the
methods employed over time to collect information about our solar system
and beyond
Research Activity Collecting information about the solar system and beyond
Introduction
Exploring the Heavens
Throughout history humans have gazed at the stars. Early stargazers began to
notice that the brighter stars formed patterns in the night sky. They traced out these
star patterns and gave them names. These star patterns are called constellations.
In all there are eighty-eight constellations.
Having learned to pick out certain stars by their positions in constellations, the early
stargazers came to realise that the events in the sky repeat themselves over and
over again. From the repeated observations about the times the sun, moon and
planets appear, people slowly came to develop the first calenders. These calenders
allowed them to keep track of time and the seasons. This was important for travel
and agriculture. Man’s survival and good fortune was linked to an understanding of
astronomy.
Some of the Greek astronomers were very careful observers, and kept long and
detailed records. What was particularly important to them was to explain the
universe. For thousands of years the study of the heavens was only possible with
the unaided eye. On a clear night there are about 4500 visible stars. To help in the
mapping of these stars a number of instruments were developed.
Before the invention of the telescope a number of objects were identified in the night
sky. Five planets are visible – Mercury, Venus, Mars, Jupiter and Saturn – as well as
the earth’s one moon. On a clear night about five shooting stars or meteor’s are
visible every hour. Finally, about ten comets are visible each year. In the daytime
sky the sun dominates. Special events like the eclipses and auroras are other
astronomical phenomenon that can be viewed with the naked eye.
The development of modern astronomy depended on two important inventions – the
telescope and an accurate clock.
The true nature of celestial objects became possible with the invention of the
telescope. Galileo Galilei was the first to turn a telescope towards the stars. To his
surprise thousands more stars were now visible. He discovered craters on the moon,
sunspots on the sun, the rings of Saturn, and four moons of Jupiter.
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Toward the end of the 17th Century, the Dutch astronomer Christian Hugyens
invented the first pendulum clock. Measurements in astronomy need to be precise to
be useful. It is important to keep an accurate track of when events take place and
how long they last. Thus with the invention of the telescope and the clock modern
astronomy became possible.
Today there is a large number of devices used to explore the solar system and
beyond.
 Many bodies in space emit electromagnetic radiation. Techniques have been
developed to detect the various parts of the electromagnetic spectrum.
 Manned and unmanned craft have been sent into space for exploration.
What to do
The task
[3 marks]
Gather and process information from secondary sources
 To identify the methods employed over time to collect information about our solar
system and beyond
Marking Criteria
Identifies at least six substantially different methods
Identifies at least four substantially different methods
Identifies at two substantially different methods or several of the same type
of method
Marks
3
2
1
Notes Questions
21. What did people first use to collect information about the stars?
22. Why was the calendar an important development in astronomy?
23. Name all the astronomical objects that can be seen from the earth without the aid
of a telescope.
24. Name two important inventions used to collect information about our solar system
and beyond.
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9.9.5.d
Describe and account for the advantages of building optical telescopes on
high mountains
TELESCOPES
Most astronomical objects are extremely faint. Without a telescope you can see
about 6000 stars. Even with a small 15-cm telescope you can see half a million
stars. The real power of a telescope is that it allows us to objects in the night sky that
we would otherwise not know existed.
The main function of a telescope is to collect electromagnetic radiation (waves –
light, radio waves, infra red radiation). The bigger a telescope the more radiation that
can be gathered.
The next most important function of a telescope is to resolve fine detail. That is, to
separate, or resolve, objects that are close together in the sky. The bigger a
telescope the better the resolving power. The better the resolving power the greater
the detail that can be observed. Unfortunately, the atmosphere limits the resolving
power of earth-based telescopes.
The least important of a telescope’s functions is its magnifying power. This is the
increase in the size of the image compared to visual observation. There is little point
magnifying an image greater than necessary – detail is determined by resolving
power. Increased magnification might just make a fuzzy image larger.
WHERE TO LOCATE A TELESCOPE
A telescope must be properly located if it is to collect as much radiation as possible.
A dark sky as free as possible from human lights is needed to observe faint celestial
objects. Also, to get a steady image, the atmosphere should be clear and dry.
These conditions are usually met on remote mountains.
If the telescope is in a low-lying area, the image could be faint and distorted. The
reason is that the lower layers of air are often filled with water vapour (fog and low
lying stratus clouds), as well as with a haze of dust or smoke. Nearness to a city is
also an obstacle to good viewing. The lights of a great city can effectively blot out
fainter stars.
Notes Questions
25. How many stars are visible with a 15 cm telescope?
26. What is meant by the resolving power of a telescope?
27. Outline the three functions of a telescope.
28. Explain why magnification is not as important as resolving power?
29. Why isn’t a telescope placed near a large city?
30. How does the presence of water vapour in the air affect the image produced by a
telescope?
© P Wilkinson 2002-04
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9.9.5.e
Identify the type of information gathered about space by
–
Hubble Telescope
–
Very long baseline interferometry (VLBA)
–
Highly Advanced Laboratory for Communications & Astronomy
(HALCA) satellite working with ground-based satellites (GBS)
THE HUBBLE TELESCOPE
The Hubble Space Telescope makes observations using infrared, visible light and
ultraviolet light. The radiation is detected using cameras and spectrographs. Since
the telescope is located in space, above the atmosphere it provides the clearest
optical views of the universe to date- (resolving power is greatly increased).
It is capable of obtaining images of very faint and distant celestial objects.
Information about chemical composition, temperature and magnetic fields of these
celestial objects has been obtained. It also provides improved distance movements,
and has been used to investigate the evolution of stars and galaxies.
Specifically, it has provided:
 Images showing mysterious dark structures in the spiral galaxy M51.
 the first convincing evidence of the existence of black holes,
 views of Jupiter when fragments of the Comet Shoemaker-Levey 9 bombarded
the planet in 1994.
 Images of colliding galaxies
 Evidence that by 1998, Neptune’s moon Triton had warmed by 2 0C since the
Voyager probe visited in 1989.
VERY LONG BASELINE INTERFEROMETRY (VLBA)
Radio dishes are easier to construct than large mirrors, and therefore radio
telescopes are usually much larger than optical telescopes. For this reason radio
telescopes are more sensitive because they can collect more radiation.
Unfortunately, because of the long wavelength of radio waves, radio telescopes have
poor resolving power. That is, they have much less ability to show detail in radio
sources.
The resolving power of radio telescopes can be improved by using a computer to
join the signals received by different telescopes. The further apart the telescopes
the better the resolving power and the greater detail that can be observed. When
radio telescopes are joined using computers the device is called a radio
interferometers. A very large array (arrangement of telescopes) was built in New
Mexico in 1980.
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Very Long Baseline Interferometry uses signals received by ground based radio
telescopes in different parts of the world (Australia, Puerto Rico, Italy, South Africa,
Japan, China, Canada, US, Russia). The signals are synchronised by atomic clocks,
with high-density data recording and very powerful computers to process the
information collected. Together, this creates in an earth-sized telescope enormous
resolving power.
Some information gathered by the VLBA interferometer includes:
 the discovery of areas of silicon monoxide gas around old stars
 the first view of regions near a black hole
 detail that reduces the uncertainty about the size of the universe
HALCA
The VLBA Telescope was improved when the Japanese launched the radio
astronomy satellite ‘HALCA’ in 1997. By linking HALCA with the ground based VLBA
Telescope a larger than earth sized telescope was created. The “viewing power” of
this virtual telescope is equivalent to being able to distinguish a single grain of rice in
Tokyo from Sydney (8000 kilometres away)
The array enables imaging of violent radio emissions from stars 10 billion light years
away. Also, the galaxies Centaurus A and Virgo M87, believed to contain black
holes, have been viewed.
Notes Questions
31. Name the types of electromagnetic radiation that can be detected by the Hubble
telescope?
32. Why does the Hubble telescope provide clear views of the universe?
33. Name two examples of images collected by the Hubble Telescope.
34. Which type of telescope shows the greatest detail – a radio or light telescope?
35. What are radio interferometers?
36. What is the advantage of interferometers compared to ordinary radio telescopes?
37. Research
Draw a diagram that shows a very long baseline interferometer.
38. What is HALCA?
39. Outline examples of information collected by interferometers.
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9.9.5.iv
Gather and process information from secondary sources to trace
Australia’s involvement in space exploration
Research Australia’s involvement in Space Exploration
Introduction
 Captain’s Cooks discovery of Australia occurred after the real purpose of his
journey. Cook was involved in some space exploration – the observation of the
passage of the planet Venus across the face of the sun. This observation was to
help to improve the accuracy of methods then used to calculate longitude.
 An astronomer, Lieutenant William Dawes, was part of the First Fleet when it
arrived in 1788. Dawes made many astronomical measurements while in
Australia.
 Australia has made some significant contributions to space exploration. These
contributions include:
 Australia’s involvement in the science of radioastronomy
 Parkes radio telescope
 Radio telescopes at Narrabro and Sidling Springs
 The Australian Long Base Array
 Optical Astronomy – Mount Stromlo, Anglo-Australian Observatory
 The Woomera Rocket Range
 Launch centre at Cape York
 Australian Satellites – WRESAT
 ACRES – Remote sensing reception and applications facility in Alice Springs
What to do
Develop a timeline of Australia’s involvement in space exploration
[5 marks]
Try these Web sites
http://www.aph.gov.au/library/pubs/cib/1997-98/98cib12.htm
http://members.lycos.co.uk/spaceprojects/australia_in_space.html
Marking Criteria
Timeline contains all the following features
 Set out as a timeline
 At least six entries
 Outlines many of the significant events in Australia’s involvement
 At least three sources used that are correctly referenced
Some of the features incomplete
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Marks
5
1-4