The fascinating history of space stations

Ground crew had no idea anything was amiss until the hatch was opened, but the men themselves had known. Patsayev’s hands were bruised as he groped in vain to close the valve.

The Soviet Union at first obfuscated, but eventually the story emerged. Because the crew expired before the capsule re-entered the atmosphere they remain the only humans known to have died in space.

Ironically Soyuz 11 had succeeded where Soyuz 10 had failed. The latter had been intended to deliver the first crew members to Salyut 1 but had problems docking. Soyuz 11 was its replacement.

Despite the calamity, Salyut 1 itself was a qualified success. The first space station of any kind, it launched on April 19, 1971. After the United States had beaten the Soviets to the moon the latter had switched focus onto orbital research stations, despite limited public interest.

The first man in space, Yuri Gagarin, was a good-looking air force major who made spaceflight seem sexy. Apollo 11 was pretty cool too – nobody had walked on the moon before. Even Laika, the dog that flew aboard Sputnik II, was rather cute. But space stations? Well unless you own the Death Star, aren’t they a little mundane?

It’s an opinion that’s unlikely to change, and it’s why, although there have been stations pretty much in continuous use since the 1970s, nobody pays much attention. Well, not until somebody from your own backyard – like Major Tim (Peake) – visits. But if humans are to learn how to escape the confines of our own pleasant but limited home, it’s in space stations where the knowledge will be gathered.

And that process began when Salyut 1 entered orbit. It only had 99 square metres of interior space but the crew of Soyuz 11 spent a then record 23 days aboard conducting experiments, before returning to earth – and their deaths – after an electrical fire forced their early departure. But because the Soyuz capsules that carried crew to the station could not be redesigned quickly to avoid a similar calamity, a decision was made to let Salyut 1 burn up in the atmosphere after only 175 days in orbit. But it was the first.

Over the decades, the Soviet Union and, since its demise, Russia have continued to be the torchbearer in orbital space. US crewed flights to today’s International Space Station (ISS) ceased after the Space Shuttle stopped flying in 2011. And more recently NASA outsourced its launches to private enterprise – Elon Musk’s Space X company – although the US is currently still having to rely on Russia’s Soyuz spacecraft to transfer its astronauts to the station. Soyuz is arguably the most successful spacecraft in history and has served the entire timeline of Soviet/Russian space stations, plus the ISS.

Before Salyut we thought we knew what space stations looked like – movies and sci-fi books had pretty much told us they would be wheel- or drum-shaped with lots of radial spokes. And they would always, but always, rotate to create artificial gravity. Salyut and its successors spoiled that. We quickly learnt they were rather boring cylinders and tended to have arms made of solar panels which occasionally broke off if they got hit by an approaching capsule. And they never rotated, meaning astronauts and cosmonauts floated around inside them.

Salyut set the standard for ugly space stations and, some may argue, aesthetics have not moved on since. Seemingly ad hoc designs, with sticking-out solar panels, docking ports and antennae are still the order of the day.

The Russian Mir station would later be described as looking like four buses simultaneously arriving at an intersection and colliding.

There were to be another six Salyut stations over the next three decades (although Salyut 2 was never occupied). Some of these – known as Almaz stations to the Soviets but as Salyuts 2, 3 and 5 to the outside world – even carried secretive military programmes, armed with weapons used to destroy test satellites in preparation for an extension of the Cold War into space. The last Salyut – number 7 – burned up on re-entry in 1991.

In response to Salyut the United States launched Skylab, first mooted in the 1960s. And while the US never – outwardly at least – seemed to have the enthusiasm for orbital research stations that the Soviets did, Skylab itself was a remarkable achievement.

The ISS has accommodation space bigger than a six-bedroomed house including two bathrooms and two toilets. There’s even a gym. Skylab, like Salyut before it, was more basic – more garden shed than luxury hotel. It only had one window (apparently the most popular spot on the station), astronauts slept in hammocks strung across the living space and urine and faeces had to be collected so doctors could examine them on return.

Yet when it launched in 1973 it gave us an inkling of what might be achievable in earth orbit. Nobody was even sure humans could live in space for any extended period of time, but by the end of its tenure the total number of hours racked up by Skylab’s astronauts exceeded the entire crew-hours in space of all previous missions added together.

It was home to three crews throughout 1973 and 1974 who provided NASA with its first glimpse of how humans cope with weightlessness over long periods of time. The space station was constantly in freefall around the planet, travelling at more than 25,000 kilometres an hour, but once astronauts got over any initial motion sickness, they reported life was pretty normal.

Lessons learnt on Skylab directed future designs, such as those for the Russian Mir station and the ISS, not least the mundane stuff such as abundant use of Velcro and soft areas to avoid head bumps and instrument damage, as well as the generally scorned zero-gravity showers.

But like Salyut, Skylab wasn’t all plain sailing. There was trouble from the off when its meteoroid shield deployed inadvertently just after launch. It ripped away and the first crew had to repair it. Once onboard, they spent time coming up with DIY fixes such as deploying a makeshift parasol to protect the station from solar heating. And a leak in one of the engines had the second crew on the verge of emergency rescue until they dreamt up another eleventh-hour fix.

Although the intention was to continue using the station after NASA’s space shuttles began flying in 1981, Skylab was never occupied again. It met an undignified end, burning up in July 1979 over the Indian Ocean and Australia, where mangled parts peppered the outback, fortunately without causing injury.

By this time the Soviet Union had begun work on Mir. Politically, Mir had a fascinating history. It began life owned by the Soviet Union but, following that nation’s rapid break-up in 1991, it was suddenly under Russian jurisdiction. All of which made life interesting for cosmonaut Sergei Krikalev. He had launched from Kazakhstan’s Baikonur cosmodrome – then part of the USSR – on May 8, 1991, as a Soviet citizen. He would return on March 25, 1992, as a Russian citizen, with his landing site now in independent Kazakhstan. “I thought the space programme might become bankrupt,” he later half-joked, “meaning I might never get back.”

Beyond politics, Mir was innovative. It was the first ‘modular’ space station – paving the way for the ISS. Small sections were constructed on earth and launched into orbit – the first in 1986 – where they were assembled. Cosmonauts lived in one section while another was being added and it was 12 years before it was complete.

Although Mir outlasted its expected lifetime by about a decade – meaning by the time it was abandoned in 2000 it was cramped, noisy and rackety, with the interior apparently smelling notoriously of sweat and alcohol – its extended lifetime did allow it to set a number of records, including the longest human spaceflight. Presumably Valeri Polyakov had become inured to the odour after his mammoth 437 days aboard.

Mir orbited at relatively low altitudes (as does the ISS at times), little more than 350 kilometres above the earth. At this level there is a vast amount of space debris. A piece as big as a defunct satellite or as small as a fragment of dried paint could puncture or even destroy the station. But operating at such altitudes had scientific benefits and Mir delivered.

It studied earth’s environment and meteorology, and carried out numerous experiments in zero gravity – the first wheat grown from seed in space was on Mir. But it was also home to bags of trash that never got taken away, food crumbs and hairs floating around that stuck in the cosmonauts’ ears. And did I mention that smell?

Mir was a political game-changer in other ways too. It was one of the instigators of international co-operation in space. The Intercosmos programme saw cosmonauts from nine other nations visit Mir – including Britain’s first cosmonaut, Helen Sharman who flew to Mir with Krikalev. And after the demise of the Soviet Union, US space shuttles visited – the first meetings in space between Americans and Russians since the one-off Apollo-Soyuz project of 1975.

Indeed, the Mir 2 space station (along with the US Freedom station planned for the 1990s) was cancelled in favour of building the ISS in collaboration with other nations. Although cost was a factor, quite bluntly there was no longer any ideological necessity for going it alone in space.

Having survived a fire, collision with spacecraft and, at one point, depressurisation – causing the cosmonauts to rapidly don protective suits – the abandoned, but still fondly loved, Mir burnt up over the Pacific in 2001. It had made more than 86,000 orbits and hosted 125 residents. By this time the ISS was aloft, having launched in 1998, and was jointly run by the space agencies of Russia, the US, Canada, Japan and Europe. It was a model of international co-operation but it arrived at a time when another nation was keen to make its own mark in space.

China’s Tiangong project remains independent of the ISS as the nation aims to build its own modular space station. Its core is expected to be launched in 2020 but there have already been two space laboratory protoypes. Tiangong-1 was launched in 2011 and also acted as a test centre for crewed space-docking, but control was lost and it burned up on re-entry last year. Tiangong-2 launched in 2016 and was occupied briefly.

Both were merely intended as stepping stones for the launch of China’s main module next year but it’s fair to include them in any list of earth orbital stations because they were launched uncrewed and subsequently visited by taikonauts. Information on both stations is sparse, but presumably when and if China launches its main station next year, we shall learn more.

But for the moment the ISS remains the daddy, travelling at more than 27,000 kilometres an hour it has been continuously occupied since 2000 and will operate for at least a decade more. It’s so big it can be easily seen with the naked eye from earth, around which it travels every 92 minutes. It has been home to citizens of 18 nations, one of whom, Gennady Padalka, holds the record for total amount of time spent in space – 879 days over numerous missions.

And, more recently, it has been the source of an unsolved mystery. Last year a hole was found in one of the Soyuz capsules docked to the ISS. It had been drilled from the inside, covered with a low-quality patch and was slowly leaking air into space. Theories abounded – sabotage, error, a crew member wanting a ruse to return to Earth? Or somebody trying to get rid of the ISS’s own smell (apparently different to that of Mir, but unwelcoming nonetheless). It got fixed (the hole, not the smell), but the mystery remains.

Maybe the driller was bored. It’s a common complaint which probably explains why, despite all the sophistication of orbital laboratories today, some of the more childish experiments are the most repeated. Letting a blob of water float around the station until it strikes another astronaut in the face, is apparently inordinately popular.

The food is notoriously bad, usually from vacuum-sealed packs, although fresh fruit and vegetables arrive on sporadic cargo ships and there are small supplies of vodka and cognac. However, there are other issues too. Health can suffer, mainly from long-term weightlessness leading to muscle atrophy and bone deterioration. And – bearing in mind one’s colleagues – excess flatulence is a common complaint.

Orbital homes are also shared by other lifeforms. When Mir was decommissioned it was found to contain 140 species of microorganisms, many of them moulds which not only contributed to the smell, but could degrade metal and rubber. Similar moulds and bacteria have recently been discovered on the ISS, carried there by astronauts, leading some biologists to wonder if they will mutate and cause problems should they return via the same route.

Mutated bugs aside, what’s the most common problem an astronaut encounters on return to earth? Forgetfulness, apparently. In zero gravity astronauts can just let go of an item and it floats away. On earth it falls to the ground, and if it’s fragile…

Of course, these are only the stories of the stations that have been occupied. There are a host of prototypes and bits of US, Russian, Japanese and Chinese stations – as well as private platforms – in orbit, most of which are inoperative or will never see humans.

The Japanese even have a small experiment in orbit intended to check if it will ever be possible to use a space elevator to deliver crew to space stations with no need for a rocket launch.

All of which leaves us where we are today, with just one crewed station in orbit, the ISS. Many years ago the New Scientist lamented the lack of co-operation in space, arguing that single nations pursuing ideological goals were detrimental to the advancement of science. In the end it got its way: more than 100 astronauts from 10 nations have worked on the ISS. From the small acorn of Salyut has grown the mighty oak of multinational technological collaboration. The cliché is apt, space stations have proved that seeds will grow in space. And who knows, maybe that huge rotating wheel with its own gravity, tennis courts and restaurants will one day be built. But there will still be people who feel nostalgia for the smell of Mir…