This problem spills over on to Mir itself. After his shift aboard the Russian station in 1995, a European Space Agency astronaut, Thomas Reiter, compiled what amounted to a Which? report on the spacecraft. Limited storage space meant that excess equipment had to be stowed improperly wherever room could be found. Scientific apparatus had to be lashed into position in ad hoc fashion because the designed fastenings were not up to the task. "With a few exceptions, the manufacturers had not provided ... adequate means for easy handling (loops, eyes, etc), nor were there sufficient aids for fixing the equipment in its storage/working location (rubber bands, belts, etc)," Reiter observed.
These difficulties are unlikely to remain exclusive to the Russians. Nasa recently indicated that it will extend the working life of its Shuttles - the spacecraft that carry astronauts back and forth to orbiting space stations - from 2012 to perhaps as long away as 2030. "In the not too distant future, Shuttles will likely be older than their pilots," says Professor Roger Handberg, at the Center for Space Law and Policy at the University of Central Florida. As aboard Mir, it may be that old equipment is not stripped out as it becomes redundant, but is simply left dormant while modern replacements add to the clutter.
One of Mir's purposes has been to serve as a prototype environment for the International Space Station for which components are currently under construction around the world. These will be placed in orbit in a series of launches starting later this year. Research on the station is due to start in 1999, with full operation by 2002, but delays are likely as Nasa struggles to stay within budgets capped by Congress. Frustrations, tensions and dangers could build aboard this new station if the lessons of Mir have not been learnt. And the signs are that they have not.
The science that deals with how well our environment and tools are suited to their users is ergonomics - often called human factors in the US. "Human factors doesn't really get talked about much," says Handberg. "It gets pushed back, unless you have something happen."
Some scientists believe that manned missions are stunts that place astronauts in unnecessary danger and that useful work can be done using robots and other equipment working under remote control. The human factors experts are at the heart of a paradox. They are duty-bound to agree that these harsh and dangerous environments are eminently avoidable. But many share the astronauts' frontier dream. "Many of us want to be in space or have our representatives in space," says Albert Harrison, professor of psychology at the University of California, Davis, and a Nasa consultant.
The aim, then, is to make the best of a bad job. Often, the human factors scientists' wish is the engineers' nightmare. The former want more room for humans, for example; the latter want to minimise the volume of the craft for fuel economy and structural reasons.
Making provision for humans greatly increases the complexity of any craft and builds in the potential for extra problems. Proponents of manned space exploration are quick to counter that human ingenuity is often equally quick to solve the problems. This double-edged sword was in evidence aboard Mir last February, when fire broke out within a ruptured oxygen generator in the worst such accident recorded in orbit. The generator was only present to give the cosmonauts air to breathe. In the event, the cosmonauts extinguished the fire in only 90 seconds.
The emphasis has been on finding astronauts with superior psychological as well as physical make-up rather than on creating environments suited to lesser mortals. Nasa's selection process has two levels of screening. The first weeds out high-risk people with psychiatric problems. The second stage, which is now receiving increased attention, is to identify candidates with superior rather than merely safe characteristics.
Erik Seedhouse, a world champion "ultraendurance triathlete" is a current astronaut candidate. Writing in the August 1997 issue of the British Interplanetary Society's magazine, Spaceflight, he describes the importance of mental as well as physical health. He recommends time-consuming exercise such as running on a treadmill that places artificial gravitational stress on the body's long bones to counteract the effects of microgravity or weightlessness while in space.
"One difficulty is to persuade people to take enough exercise on a long mission," says Professor Heinz Wolff of the Brunel Institute for Bioengineering, one of Britain's leading experts on microgravity. Several hours a day - the commitment required to maintain fitness in space - on a treadmill is not most people's idea of fun. Exercise with an element of competition would add interest. Wolff has been trying to devise such space sports, but with little success. Many sports rely on working against gravity. Others, such as wrestling, are impractical.
Another possibility is to use the energy expended by exercising to generate electricity or pump water. Although this would make a negligible contribution to spacecraft systems, if each astronaut were required to generate a certain number of units, excess units could be swapped for other favours, building a spirit of cooperation among the astronauts and providing an incentive to exercise. "I want people to work and trade with one another, like in a medieval village with few inhabitants," says Wolff.
But soon, astronauts will be more like the rest of us. "The Right Stuff stereotype will be loosening up greatly in the International Space Station," says Dr Nick Kanas, a psychiatrist at the University of California at San Francisco. "The requirements are becoming more hetero- geneous in terms of gender, motivation and career background." In a four- year Nasa-funded study, Kanas and a Russian colleague are looking at the implications of the cosmopolitan future of space flight when the on-board chat will no longer centre on baseball and pilots' war stories.
Not only that, but the rest of us may have the opportunity to try the astronaut lifestyle. By next summer, $10,000 will buy you (and your wallet) the experience of weightlessness from a new "space experience facility" being set up by Sally Ride and other former astronauts. Parabolic flights from Florida airports will rise sharply into the air and then plunge to earth to produce the weightless conditions. A survey published earlier this year in the respected Aviation Week and Space Technology suggests that people might pay $72,000 for a five-day holiday in earth orbit.
On longer missions , there are major physiological changes that need to be taken into account. Without gravity, astronauts grow by several centimetres. Fluid in their bodies drifts out of the legs into the torso and head. Biochemical changes begin to occur, leading to muscle wastage and loss of calcium from the bones. The effects of living under microgravity have been examined on previous missions. Some changes can be combated, for example with diet supplements. Unavoidable physical changes such as increased height or astronauts' tendency to develop a stoop should be reflected in the design of their environment and equip- ment. Nasa has decreed that because of the likely international make- up of future mission personnel, spacecraft and their equipment must be designed to fit 95 per cent of people, male and female. This data is well documented, but not its distorted microgravity equivalent. Equipment today is typically designed to terrestrial ergonomic criteria, says Wolff.
Anything extra has to be fought for. The designer Raymond Loewy, who created the familiar Greyhound bus and the US President's Air Force One, insisted that Skylab, the 1970s prototype space station, have a window. "People say they can never see enough of the earth," notes Wolff. Inside, without the help of gravity, the eyes pick up the cues for bodily orientation. Lighter "ceilings" and darker "floors" provide a visual sense of up and down familiar from earth. Instruments are placed consistently the "right" way up. Pictures on the "walls" help too.
But these are relatively trivial matters. Today, Nasa's human factors experts have grown so fed up with the current space stations being treated as political footballs that they have shifted their attention to the newer and more glamorous prospect of a manned mission to Mars. But even here their work may continue to have a low priority. "My concern about the case for Mars is that there's tremendous effort to get this thing moving. Nasa has a management policy of faster, better, cheaper. We may end up cutting a lot of corners in the human factors," says Harrison. "The kind of phrase that you hear is that it's like an old car. You spend your time trying to keep it running rather than enjoying the journey."
Nasa has recently launched a sequence of unmanned Mars missions, in which the Pathfinder robot explorer has scored a first spectacular success. Two of these missions scheduled for 2001 are intended to lay the groundwork for a human landing on the red planet. One aim is to test technologies that could make the manned mission more affordable. Nasa's administrator, Daniel Goldin, believes people could be on Mars by 2010 if these technologies come good and if industrial partners join the space agency in sharing the risk of the expedition.
Ironically, the astronauts are likely to find that one of their biggest problems is boredom. The trip to Mars could take up to a year. Exercise will be more vital than ever on a mission that might last as long as three years and require its participants to be fit enough to withstand Mars's gravity in order to land and perform experiments after the outward leg.
As early as one month into the journey, astronauts would see Earth disappear to a tiny dot for the first time. Human sentiment suggests that they should have the privilege of a window to see this unique sight. But practical demands may rule it out. They may have to make do with an external camera and watch it from inside the craft on high- definition television; it won't be the same.
The increasing delay in signal transmission as the spacecraft draws away from Earth means that interactive video links with family and colleagues will soon cease. One way of tackling the growing sense of isolation is for the crew to make more decisions on their own. Although newly powerful on-board computers with artificial intelligence will be capable of doing much of this work, it is thought desirable to let the astronauts do it in order to provide a sense of fulfilment. The challenge for the psychologists will be how to assign tasks between crew members and computers.
Mary Connors of the Living Aloft project at Nasa's Ames Research Center in San Francisco is pursuing another possibility of providing a kind of "continuing professional development" using telemedia to allow the astronauts to acquire new skills on the voyage, although Nasa are quick to add that this does not imply sending astronauts up half-trained. Perhaps they will use the time to pick up a little conversational Martian.
Privacy is another concern on long missions. Even aboard the comparatively spacious Mir, it has been found that cosmonauts become territorial, especially when the work is dull. With its several linked modules, Mir permits this withdrawal. "Of course, one would like to create as much real space as possible," says Harrison. "Given the stresses, a place to retreat is of some value. But one can create the impression by various design techniques that the spaces aren't quite as cramped as they are."
Times and places can be designated as special. Scientists in space work shorter hours at weekends. "But what if there was a compartment at the end of the spacecraft where you could go 'on holiday'?" asks Wolff. It seems certain that virtual reality apparatus will be important on any Mars mission to create fantasy environments. Combined with an exercise bike, for example, a video headset would allow an astronaut to cycle through a landscape - more than likely an idyllic earthly one.
Other forms of escapism such as drugs and alcohol have been ruled out. The military fears they could impair thinking in a crisis. More to the point, in the civil world of Nasa's made-for-TV space programme, it is felt that American tax payers would not condone such high jinks.Reuse content