History was made on November 2, 2000, when two Russian cosmonauts and one American astronaut became the first live-in guests on board the International Space Station.
Since that remarkable maiden journey, the vast floating facility has welcomed no fewer than 241 space travellers from 19 countries – including the UAE.
As with any major milestone, the 20-year anniversary has prompted space experts to look to the future of the iconic space station as well as honour its trail-blazing past.
There is plenty of discussion about when the ISS, a joint project of space agencies from Canada, Europe, Japan, Russia and the US, will eventually be retired.
Commercial space travel on the rise
Today the Low Earth Orbit (LEO) scene, of which the ISS is part, is increasingly commercial, with multiple private enterprises involved, and it is they, rather than national space agencies, that may replace the $150bn (Dh550.95bn) facility.
The commercial sector’s growing input to ISS has been demonstrated most dramatically this year by Elon Musk’s SpaceX aerospace organisation, which took two Nasa astronauts up to the facility at the end of May using a Crew Dragon spacecraft and Falcon 9 rocket.
At the time, Nasa noted that it was the first time its astronauts had been taken up to the space station from American soil by a commercially built spacecraft.
Another commercial transportation programme is being developed by Boeing, which has a long history of involvement in the ISS, having been selected by Nasa as its main contractor for the facility back in 1993.
Boeing’s attempt in December to send its Starliner spacecraft up to the ISS went awry when a timing issue prevented a planned docking of the uncrewed vehicle, but another attempt is scheduled for January.
Before then, in mid-November, SpaceX is set to take three American and one Japanese astronaut to the ISS on its second crewed mission to the facility.
Their arrival will expand to seven the number of people at the ISS, which currently plays host to two Russian cosmonauts, Sergey Ryzhikov and Sergey Kud-Sverchkov, and one American astronaut, Kathleen Rubins. They have been there since mid-October and are due to return to Earth in April 2021.
Life on space station offers unique challenges
Speaking from the ISS during a recent question-and-answer session to mark the 20th anniversary, Dr Rubins said the toughest activities they had to undertake were space walks or extravehicular activity (EVA), two of which she completed during her first ISS mission, in 2016.
“This is probably the foremost mental and physical challenge we have as astronauts – to be outside in the vacuum of space in a 400-pound space suit moving that mass around with very, very expensive equipment,” she said.
“That being said, it’s also one of the most fun things we do, so we’re looking forward to many space walks, many EVAs ... It’s going to be a great expedition.”
Lt Col Ryzhikov, the mission commander, and Mr Kud-Sverchkov are set to carry out a space walk in mid-November, according to reports.
As well as space walks and routine maintenance, ISS residents have over the years undertaken nearly 3,000 experiments analysing things such as how the human body functions in space.
In recent years more commercially funded technical projects have been undertaken, an indication of Nasa’s keenness for private-sector involvement.
Nasa to sell off ISS stake?
Analysts say Nasa is keen to ultimately hand over its portion of the ISS to the private sector so that the billions of dollars a year it spends on the ISS could go to other programmes, notably those involving the moon.
Dr Rubins, a microbiologist, compared the facility to a scaled down university campus with cutting-edge equipment including DNA sequencers and sophisticated microscopes.
“We’re going to continue some of the work on growing cells – we’re going to be growing heart cells,” she said.
“I’m looking forward to a lot of the microbial experiments. I’m looking forward to looking at the station’s microbiome [complement of microorganisms].
“I’m interested in learning who’s here in terms of the microbial populations. Who’s here and who’s changing over time.”
The ISS is not just focused on biological experiments, as it also has specialist equipment for research in fields such as physics or materials science.
When he spent eight days on board the facility after arriving on a Soyuz rocket in September last year, the UAE’s first astronaut, Major Hazza Al Mansouri, undertook a series of experiments, including some with a robotic camera aimed at offering insights into how the orientation of spacecraft can be controlled.
After Maj Al Mansouri’s trip, the UAE recorded another key milestone in its space programme in July this year, when the country’s Mars Mission, Hope, which is spearheaded by the Mohammed Bin Rashid Space Centre, blasted off from Japan. It is scheduled to reach the Red Planet in early 2021.
One experiment due to happen on the ISS in the coming months is the growing of radishes, work NASA says could optimise methods to cultivate the vegetable in space.
Could space station be a tourist attraction?
In the years to come, Nasa is opening up the ISS to visits by tourists – with transport there and back on commercial craft costing tens of millions of dollars – and, in January, it gave approval for a private space company, Axiom, to attach a commercial module to the ISS.
Axiom, which is run by a former Nasa ISS programme manager, ultimately hopes to attach several modules to the ISS, the first of which could be launched in 2024 and allow for new experimental facilities and living space.
The company has said work on the ISS could move over to the commercial modules when decommissioning finally happens.
Once it is retired, the ISS would probably be crashed into a remote part of the Pacific Ocean, joining the remains of Russia’s Mir space station, which burned up before reaching its watery grave.
The ISS’s retirement is, however, not imminent: it is scheduled to remain in operation until at least 2024 and much of its hardware is certified for use until several years after that.
Speaking at the recent press conference, Lt Col Ryzhikov acknowledged there is currently a leak in the ISS that needs fixing, but said the overall structure was sound. Boeing too said earlier this year the ISS was in good shape.
“It has very reliable construction,” said the Russian cosmonaut, who is his second ISS mission. “It has various small leaks every day. Now it’s a little bit more than standard. We’re working to find it and replace it. So don’t worry.”