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International Space Station

Dr Duncan L Copp

Updated June 2003

It's billed as the only sophisticated scientific outpost in space. Complete with six laboratories, it represents the most complex international construction project to date – the International Space Station is an ambitious undertaking. Advocates see it as a shining new star in orbit, set to change the course of human history. But critics say it's too costly with too little scientific return. Is the International Space Station really necessary?

Orbiting 402km (250 miles) above our heads, the space station, already manned, represents the largest structure ever built in space. When completed it will be four times the size of the late Russian Mir Space Station – measuring 109m (356 feet) across and 88m (290 feet) long, with solar arrays covering 4050m² (1 acre). The internal volume of the space station will be equivalent to the internal volume of a 747 passenger cabin.

Eventually, 100 major components, with a total weight of 454 tonnes, will have been ferried into orbit aboard over 40 space flights by at least three types of rockets: the Russian Soyuz, the Russian Proton and three of the four US space shuttle fleet.

Supporters promote the space station as a place where many areas of scientific research will be revolutionised. Yet opponents have baulked at the cost – now US$95 billion. They say that similar research can be done for less money with unmanned satellites, or here on Earth. And now, three years into the assembly stage, after an investigation ordered by Daniel Goldin, Nasa's former chief administrator, Nasa has been criticised by an independent panel for overspending. Their project management was described as 'not credible'. Such a damming report is sure to shake the very foundations of the project.

Yet controversy has accompanied the station since its conception. Indeed the road to the newest frontier in space has been long and difficult.

The long and winding road

Reagan years

Initiated by President Reagan in 1984, the space station, originally called 'Freedom', was conceived in order to strengthen America's position in space both scientifically and politically. Reagan saw the space station as offering political advantage over the Eastern Bloc and announced that he wanted Freedom in orbit within a decade. But Congress began to splutter at the project, especially during the era of 'glasnost' and after the 1986 Challenger disaster, resulting in the budget being capped at US$8 billion.

Bush years

By the early 1990s, the price tag had risen to an estimated US$30 billion and now Congress had their knives out for the project. Meanwhile, President Bush was distracted by the prospect of a manned mission to Mars. Surely it had become too expensive and now, with changing relations between the US and Russia, no longer had political advantage? But in 1993, funding for the station was approved, after winning a majority in the House of Representatives – by just one vote.

Clinton years

With the collapse of the Soviet Union and the break-up of the Eastern Bloc, President Clinton capitalised on the new political climate. He saw the space station as a symbol of post Cold War co-operation. Clinton renamed the project 'Alpha', and referred to it as the International Space Station, or ISS. Russia was invited to join the program along with the original members – Japan, Canada, Brazil and 11 countries of Esa (European Space Agency), including the UK. Ten years after its initial conception, the space station finally left the drawing board. The participating nations set to work making the individual components, the first of which were Russian-built.

Originally, the US-Russian pairing was seen to be of mutual advantage. Nasa lacked the 'on-orbit' experience gained by its Russian counterparts. Not since 1973 had Nasa had any of its astronauts in orbit for more than a week or two. Some Russian cosmonauts had clocked up well over a year in space on their Mir Space Station, which had been in orbit since 1986. On the other hand, Mir was an aging station, its technology far from reliable and Russia had little resources to fund its own space program. However, teaming up with the Russians was seen by many to be an Achilles heel — their unhealthy bank balance could cost the US heavily.

In an agreement that saw American astronauts spending anything up to four months at a time on Mir, Nasa gained experience in long duration space flight. In total, seven astronauts spent 32 months onboard Mir during the 1990s. The astronauts also tackled a number of unexpected surprises, including an onboard fire, a colliding supply module, and a total loss of power and communications. Such life threatening situations on their own station were a major factor in why the Russians wanted to join the ISS programme. Eventually Mir was abandoned and guided to a fiery death, burning up in the Earth's atmosphere in 2001.

Embroiled in its own political problems since the fall of the Soviet Union, Russia experienced cash flow problems, and the first key modules flew late and were over budget. Nevertheless, the first part of the space station, a 22-tonne space tugboat, was successfully sent up in 1998. Deliveries continued, and in November 2000, the Expedition-1 crew of one US astronaut and two Russian cosmonauts became the first people to live and work on the space station.

Science in the Sky

Medical research

One advantage of the ISS is its location in a low gravity environment (almost zero gravity). Low gravity is particularly useful for medical research, as it's possible to grow purer protein crystals and tissue cultures in space than it is on Earth. This is because in space, crystals are able to grow equally in all directions without gravity bearing down upon them. Here on earth, crystal growth is restricted in one or more directions, leading to imperfections. Protein crystals are used to study the nature of proteins, enzymes and viruses, the results of which may be used to develop new drugs to help fight cancer, diabetes and immune system disorders. Tissue cultures may also be used to test new cancer treatments.

However, there is a major problem with carrying out delicate experiments, like growing crystals, on a manned spacecraft. Because astronauts tend to float around in a less than delicate manner, they introduce vibrations through bumps and bangs. Such man-made tremors can 'pollute' very delicate operations. The problem is compounded in the space station as the whole structure tends to vibrate when the space shuttle docks. Back on Earth, a number of medical research areas, including protein crystal growth, have advanced leaps and bounds during the protracted history of the station. Prompting some scientists to argue that experiments on Earth will soon rival those planned for the space station and cost just a fraction of the price.

Mixing metals

Another bonus of the low gravity is the reduction of convection currents. Anyone who has gazed at a lava lamp will have seen convection in action. The dense coloured wax which sits in a light fluid rises when it's warmed by the heat from the lamp bulb. The wax rises because as it warms it expands and becomes less dense before cooling and sinking. This process is called convection. In low gravity, convection does not occur because nothing has any weight. The lack of convection is a great advantage to scientists wishing to mix metals, since liquids that would normally separate by convection no longer do so in low gravity. Research into mixing metals to make new alloys under such conditions is likely to benefit microchip industries here on Earth.

Humans in space

Studying the long-term effects of weightlessness on the human body is also proposed onboard the ISS. Studying the effects on the body when it adapts to low gravity (such as loss of bone density and muscle wasting) will be useful in predicting and reducing problems when humans finally undertake missions to Mars. Astronauts on a trip to Mars may spend up to three years in a gravity field much lower than Earth's and must understand what effects this will have on their body. The ISS is the only structure in space where the effects of low gravity on people, plants and animals can be investigated over a long period of time.

Constructing such a vast structure in the harsh environment of space, will be of considerable benefit if we are ever to really exploit the 'final frontier'. From small hand-held drills and spanners, to the 55-foot long Canadian robotic arm, astronauts will spend around 1000 hours outside bolting, wiring, fastening and latching the station together. The time spent in the harsh vacuum of space on these demanding and dangerous space walks represents three times Nasa's total space walk tally over 30 years.

Environmental monitoring

The ISS's orbital inclination allows 80% of the globe to be observed, flying over 95% of the world's population. It provides the perfect opportunity for monitoring climate, the oceans, geological activity such as volcanology, agricultural patterns and pollution. With an ever-increasing global population, the need to monitor pollution, like urban smog, oil spills and deforestation will be more important over the next few decades. Having a permanently manned outpost in space, providing a unique perspective on the Earth, is likely to reinforce the need to protect the planet.

Inherited technologies

As with any major space undertaking, a whole plethora of new technologies have spawned from the complexity of designing and building the International Space Station. New robotics, improved lightweight space suits and new lightweight materials are just a few examples that will eventually benefit commercial and industrial sectors on Earth.

Back to Earth ... with a bump

The science objectives will come at a price: a price that keeps escalating. Even though construction continues, the recent findings from the report commissioned by Nasa, and the current cost of US$95 billion, will no doubt force Congress into a radical review of future space station funding. To tackle the cost overruns, the report recommends reducing the space station's work force and the number of shuttle flights, currently costing approximately US$368 million per launch, from six to four flights a year. Cutting back on the project, however, is likely to reduce the amount of scientific return, the principal purpose of the station. As the new millennium begins, the full construction and operation of the International Space Station, as originally planned, hangs very much in the balance.

Today

In recent months a tremendous blow has been dealt to the ISS. It's always been acknowledged that the loss of a space shuttle during construction of the station could cause considerable delay, or scupper the program altogether. Tragically, this concern became reality when space shuttle Columbia (the only shuttle unable to dock with the ISS) disintegrated during re-entry on 1 February 2003, after a highly successful 16-day science mission.

Since November 2000, ISS crews have been replaced every few months and completion of the station was set for 2006. But with shuttle flights grounded for the majority of 2003, continued construction of the ISS is on hold. It's unlikely the station will be abandoned as too much time and effort has already been invested, but the reliability of an aging and now diminished shuttle fleet is in question. It seems then that the International Space Station faces yet another pivotal point in its history.

The ISS Expedition-6 crew, Commander Kenneth Bowersox (Nasa) and flight engineers Nikolai Budarin (RSA – Russian Space Agency) and Donald Pettit (Nasa), were launched on 23 November 2002 on Endeavour. They were scheduled to return in mid-March 2003 on Atlantis but their return was delayed owing to the grounding of the shuttle fleet after the loss of Columbia.

A Soyuz flight with an unmanned Progress vehicle was successfully launched on 2 February 2003 for a refuel and logistics flight, taking up supplies (food, water, fuel, etc) to maintain the three for several extra months of nominal activities. The men finally returned safely to Earth onboard a Soyuz capsule on 3 May 2003.

A replacement skeleton crew of two, Russian Yuri Malenchenko and American Edward Lu (the Expedition-7 crew), blasted off from Baikonor space centre in Kazakhstan using a Soyuz rocket on 25 April and docked with the ISS three days later. The two are scheduled to work aboard the station until October 2003.

You may also be interested in these other Channel 4 articles

Mir Space Station
History of the stage on which some of the most notable and dramatic episodes in space were played out.

Hubble Space Telescope
History of the telescope that's providing an enlightening new window on the Universe.

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