Living and working in space.  Triumphs, tragedies and everyday practicalities on the Russian space station Mir and America's Space Shuttle.
 

Outline:

The effects of gravity on Earth, the joy of weightlessness in space.  How hurtling around Earth in "free-fall" creates zero-gravity in a spacecraft and how its velocity keeps the craft in orbit.  The velocities required to achieve orbit and to escape entirely the pull of Earth's gravity.

The story of the Space Shuttle.  Why it replaced the expendable rockets of the Moon programme.  The main characteristics of Shuttle - and its functions.  The Challenger Shuttle disaster.  The Mir space-station and its link-ups with the Shuttle.  Aspects of life in space, working aboard Shuttle and Mir.  The practicalities of eating, drinking, sleeping and washing in zero gravity.  The importance of a strict exercise regime while living in space.  Leisure activities - like partying and Earth-watching.

Mishaps in orbit including Mir's collision, in 1997, with a cargo module.  A tour of Mir's labyrinthian interior.  Shuttle's role in space, including the deployment and retrieval of satellites, with assistance from spacewalking astronauts.
 
 

Sub-chapters:
 

Pull of Gravity

*  Concept of Earth's gravity and its effects on us.

*  Depictions of a weightlessness aboard American and Russian spacecraft.

*  Launch velocities required for space travel.  Insufficient velocity results in a sub-orbital hop.  A 27,000 kilometre-per-hour thrust is required to reach Earth orbit.  Speeds in excess of 40,000 kilometres per hour will achieve escape velocity - and break free from the pull of Earth's gravity.
 

Shuttle and Mir

*  All about Space Shuttle.  It was developed to be more cost-effective than the expendable rockets of the Moon programme.  Shuttle launches as a rocket, orbits as a space station and lands on a runway like a glider.  Shuttle's limit is Earth orbit.

*  January 28, 1986: the Challenger Shuttle disaster.  A ruptured seal triggers an explosion, killing all seven crew members.

*  The Mir space-station, a permanent laboratory, 400 kilometres above Earth.

*  Dockings between Mir and Shuttle.
 

Eating and Sleeping

*  Living aboard Shuttle and Mir.  Monitoring the effects of weightlessness on the human body.

*  Space food is glutinous to prevent crumbs and spicy to stimulate appetite.

*  Sleeping quarters - either a cubicle or strapped to the superstructure.

*  Mir's 90-minute orbit of Earth -16 sunrises and sunsets each day.
 

Body and Soul

*  Haircutting with a vacuum cleaner to collect floating hairs.

*  Shuttle's $15 million toilet and Mir's more primitive facilities.

*  Hair-washing with waterless shampoo.

*  Russians know most about selecting compatible crews.

* Relaxing in space - a sing-song.
 

Earth-Watching, Working Out

*  The joy of observing features on Earth.

*  The importance of exercising in space.  Weightlessness leads to muscle wastage and other problems.
 

Please note:  In the British English and American English streams of the DVD,  "Earth-Watching, Working-Out" is not programmed as a separate sub-chapter.  The subject matter of "Earth-Watching, Working-Out" is incorporated in "Body and Soul".  If you enter "Earth-Watching, Working Out" on the DVD, you will be offered the next sub-chapter "Mir Problems" which also plays if you enter the sub-chapter correctly titled "Mir Problems".  Apologies to our English language users for this confusion.  This error does not occur in the Dutch, French, German, Japanese and Spanish streams.
 

Mir Problems

*  Mir's many troubles - cosmonauts making repairs outside the spacecraft.  Internal fires,  computer breakdowns and collision with a cargo module in 1997.

*  A tour of Mir's cramped, tunnel like interior.  Uncomfortable, but Mir generates a wealth of invaluable scientific data.

*  Shuttle's role as a "space truck", launching satellites and retrieving them for repair.  Observing the Earth for scientific, agricultural and military purposes.
 
 

Background:

Defying Gravity

If a ball is thrown into the air, it reaches a certain height then falls back to the ground.  It returns because of the force of gravity, the same force that keeps our feet firmly on the ground.  The Earth, the Moon, the Sun and all the stars have their own gravity.

If the ball is thrown a little harder, it will rise to a greater height before falling back.  If, however, you could throw the ball into the air at a speed of 40,000 kilometres per hour, it would never return to the ground.  Earth's gravity would not be strong enough to pull the ball back, and it would escape into space.

The speed of 40,000 kilometres per hour is called the Earth's "escape velocity".  For a  spacecraft to completely escape Earth's gravity and journey outward into space, the craft must travel at 40,000 kilometres or more.

The 19th century had some fanciful ideas on how escape velocity might be achieved.  Jules Verne proposed firing space vehicles from a huge gun.  He hadn't reckoned that the sudden jolt of the firing gun would kill any people on board.  Another means had to be found to overcome the pull of Earth's gravity.  Balloons and conventional aircraft are no good because they only work when surrounded by air.  It supports them and provides the required lift - unlike the airless vacuum of space.

In 1895, a shy, deaf Russian teacher named Konstantin Tsiolkovskii suggested the use of rockets.  He calculated the speed and the amount of fuel a rocket would need to carry it into space.  He proposed using liquid instead of solid fuels, and using multi-stage rockets to get into orbit.  Tsiolkovskii did not build a rocket himself.  At the time nobody took much interest in his idea.

It wasn't until the 1920s that American rocket pioneer Robert Goddard launched the first successful liquid-fuelled rockets.  Rocket research was also carried out in Germany before the Second World War by men such Werner von Braun.  He developed the first really effective high-altitude rocket, the V2.  After the war, the V2 and later designs were developed for space travel.

The US Space Shuttle does not need to travel as fast as 40,000 kilometres per hour, because it remains in Earth orbit.  Shuttle doesn't have to reach escape velocity.  But to achieve orbital velocity, Shuttle has to generate sufficient thrust to attain a speed of 27,000 kilometres per hour.

Space Shuttle has three main rocket engines that use fuel from a huge separate External Tank (ET).  At launch, Shuttle rides on the back of the giant ET.  This holds the liquid hydrogen and oxygen fuels that are pumped to Shuttle's main engines.  Shuttle blasts off with the help of two giant solid rocket boosters.   After about two minutes, when Shuttle is 45 kilometres above the ground, the boosters drop away and the Shuttle continues into space using only the thrust of its three main engines.  From lift-off to Earth orbit takes less than ten minutes.
 

Living in Space

Astronauts can live relatively comfortably in space.  The cabin of a spacecraft is filled with normal air - pressurised, so that it pushes on the human body just as air does on Earth.  Within the craft, astronauts wear day-to-day clothes.  Life-support systems maintain the right air pressure.  They also keep it clean so that it can be used over and over again.  The air is kept smelling fresh by filters which remove the water vapour and poisonous carbon dioxide that astronauts breathe out.

On the US Space Shuttle, fuel cells generate electricity by means of a chemical reaction between hydrogen and oxygen, producing water as a by-product.  Until recently, the Russians used solar panels to make electricity from sunlight.  Fresh water was brought up from Earth. The latest Russian spacecraft will also use fuel cells.

The main difference between living on Earth and in space is the feeling of weightlessness. Everything, including the astronauts, drifts around inside the spacecraft if not fixed down.  To envision weightlessness, look up at the ceiling and imagine a book lying there.  To retrieve it, you push gently from your chair.  You slowly rise to the ceiling.  Then, a soft push against the ceiling returns you to your seat.

Sleeping in space is like "sleeping on a cloud".  The body feels no pressure from bed or couch. You can sleep just floating around - or inside a lightweight sleeping bag taped to the side of the spacecraft.  And you can sleep in any position, even upside down.  When you are weightless, it all feels the same

Liquids don't flow in weightlessness, so drinks won't stay in cups.  If they escaped, drops of orange juice, for instance, would just float around inside the spacecraft.  Drinks have to be sucked through a plastic straw from a sealed container.

In space. you can eat normal food, but it must be sticky to stay on your spoon or fork.  Food is eaten from special packages on a tray that clips to a seat or table.  When not in use, magnets stop knives, forks and spoons from floating away.  Trays and cutlery are wiped down and re-used.  Some food is dried (de-hydrated), requiring hot or cold water t be added before  consumption.
 

Coping with Weightlessness

Once in space, astronauts are busy people.  During their first few days in orbit, however, space sickness is quite common and causes temporary discomfort.  To keep fit and well, astronauts must take plenty of exercise, particularly on long-duration missions.  In the weightlessness of space, muscles are deprived of their constant battle against gravity on Earth.  Muscles lose tissue and function less well.

In addition, body fluids are no longer pulled downwards by gravity.  Instead, they migrate  towards the astronaut's head.  This causes fat faces and blocked nasal passages.  Belts are worn at the top of each leg to help control fluid flow until the body adjusts to space.  The upward movement of fluids also causes the kidneys to excrete more urine, upsetting the body's salt concentration.

To prevent serious physical illness and to make the return to Earth-gravity less uncomfortable, astronauts must have about two hours of exercise a day.  They use exercise bicycles and treadmills.  Legs and arms and the heart - the most important muscle of all - are put through their paces in space.  While exercising or working, astronauts stay put by using special hand holds, footholds and seat-belts.

From 1986 to 1999, Russia's Mir space station was home to astronauts from many countries.  Two or three crew members were usually on board, but Mir could take up to six.  Mir was  visited by crews of the US Shuttle, which docked with the station.  Astronauts have remained on board Mir for many months at a time.  They have collected valuable information about how the human body copes, both mentally and physically, with long periods of weightlessness.    The record for the longest unbroken stay by one person - 438 days by Dr Valeri Polyakov - was achived aboard Mir.

The fact that cosmonauts have returned to Earth after long stays aboard Mir with no lasting ill effects bodes well.  It has proved that well disciplined people can survive long periods of weightlessness in the cramped confines of a space station.   This is good news for future ventures like the International Space Station, which will be permanently-manned, and for the  colonies of humans that one day must inhabit the Moon and Mars.
 

Working in Space

Astronauts work both inside and outside a spacecraft.  Inside, there is routine maintenance and the monitoring of onboard systems, as well as scientific testing and experimentation. This can include investigations on the effects of weightlessness on the human body, the testing of new space products, and research on behalf of commercial organisations who pay to send experiments to be performed in weightlessness.

Work outside the craft may involve the deploying or repairing satellites, setting up experiments, testing new equipment, or evaluating techniques for the assembly of future space stations in orbit.

Together with the Shuttle commander and pilot, a crew includes "payload specialists" and "mission specialists".  These are scientists with special skills who carry out experiments or handle payloads.  Shuttle's cargo bay can accommodate several small loads and two or three satellites.

Satellites are pushed gently out of the bay by a special robot manipulator arm.  Then, they are  tested in orbit.  Lifting requires no effort in space.  Nevertheless, satellites must be moved with great care.  The manipulator arm is worked by remote control from inside the Shuttle, the operator looking through a window on to the cargo-bay.  The arm is over 15 metres long and is jointed like a human arm.

Shuttle can be used for repairing or retrieving faulty satellites in low Earth orbits.  Fixing a satellite is a tricky business.  Shuttle is first brought up very close and the manipulator arm is extended towards faulty object.  Astronauts then have to take a spacewalk to carry out repairs.  This is called an Extra-Vehicular Activity (EVA).   The astronauts may have to fit new parts to the satellite or replace damaged ones.  Often the EVA workers need to attach themselves to the manipulator arm to avoid drifting off into space.

Clad in spacesuits, the crew leaves and enters the spacecraft through an airlock.  Each suit has over 15 layers of plastic and metal to protect the astronaut against the extremes of hot and cold in space.  Suit and helmet are perfectly sealed and correctly pressurised.  A backpack contains a life support system, supplying the wearer with air, food and water.  Sometimes an  astronaut uses a manned manoeuvring unit (MMU) for moving around outside the spacecraft.  The MMU is shaped like a chair and worn like a huge backpack.  It has 24 small thrusters that squirt jets of gas propel astronaut hither and thither.

And leisure time?  Much as on Earth.  Astronauts keep in touch with family and friends via laptop computers.  Then, there's reading, photography, listening to music or playing cards.  Whatever the preferences, these orbitting astronauts spend a considerable time just gazing at the ever-changing Planet Earth.
 
 

Links for Further Information:

Comprehensive page detailing all aspects of Shuttle missions, including launch dates,  objectives and highlights - plus images.
http://www.ksc.nasa.gov/shuttle/missions/missions.html

Mir space station home page, including news, history, research projects, archive, images and links.
http://www.maximov.com/MIR/index.html

Living in space - an informative page with links to health, fitness, loneliness, living conditions and crop cultivation in orbit.
http://www.tv.cbc.ca/national/pgminfo/space/livingspace.html

Excellent spacewalking site, detailing the history of spacewalking and spacesuits, the conditions in space, and the Manned Manoeuvring Unit now used by astronauts working outside Shuttle.  Extensive images.
http://quest.arc.nasa.gov/space/teachers/suited/1intro.html

Interesting page, describing various effects on the body of a weightlessness.
http://shuttle.nasa.gov/index.html/aging.html

Exhaustive Shuttle images library.
http://www.ksc.nasa.gov/mirrors/images/html/shuttle.htm
 
 

Questions and Activities for the Curious:

1.  Describe the main components of the US Space Shuttle at lift-off.

2.  Research the circumstances that led to the explosion of the Challenger Shuttle in January 1986.

3.  What characteristics are important when choosing people to live and work together within the cramped confines of a space station?

4.  Describe a typical meal-time in orbit.  How it would differ from meal-time on Earth.

5.  Discuss the problems that long periods of weightlessness pose for the fitness and health of astronauts.

6.  Summarise achievements aboard the Soviet/Russian space station Mir since the launch of its first module in February 1986.

7.  Imagine you are to spend six months orbiting the Earth aboard Mir.  What would you most look forward to and what would you least relish?

8.  What particular hazards are posed by a fire aboard a space station?