Voices November 16, 2020
20 years of human presence on the International Space Station
By Peter Vogel
It is one of the wonders of the world, a tribute to scientific curiosity and ingenuity, and it represents the pinnacle of space exploration.
It is the International Space Station, better known as just the ISS. Earlier this month the ISS celebrated 20 years of continuous manned presence. But the ISS is showing its age. Air leaks, failing toilets, cooling system breakdowns, spiraling operating costs.
Still, it remains a leading example of cooperation between nations for one of mankind’s most complex science laboratories.
An argument can be made that everything on the ISS could be conducted without human presence, but those 20 years of manned presence have given us insight into the effects of microgravity on the human body that we simply could not get from shorter duration stays in smaller craft.
Here are some facts about the ISS and experiences for those who spend time on it.
16 sunrises/sunsets a day
Orbits about 420 km above the earth
Moves at about 28,000 km/h
Crosses about 90 per cent of the planet each day
93 per cent of water on the ISS is recycled
Easy to see under the right conditions, being among the brightest objects in the night sky
It is big, as in football field-sized big
Up to eight craft can be docked simultaneously to the ISS
There are about 100 laptops aboard the ISS
In 2013 the main operating system aboard the ISS was switched from Microsoft Windows to Debian Linux
Among subjects studied on board: flames, microbes, 3D printing, fluid properties, tissue chips, crystal formation, black hole formation
Combating muscle and bone mass loss for long-stay astronauts requires around two hours a day of exercise
Amateur radio operators can send data packets through a repeater on the ISS, and a recently installed repeater allows voice contacts
Lead agencies are NASA, ROSCOSMOS, CSA, ESA, JAXA (USA, Russia, Canada, Europe, Japan).
Construction of the ISS began in 1998 with an initial module launched by Russia. Nearly all subsequent construction consisted of modules delivered by the now retired space shuttle. By Nov. 2, 2000, the ISS was ready for continuous, long-term habitation, that anniversary being celebrated this month.
While typically manned by a crew of six at all times, there have been as many as 13 aboard at one time. Almost 250 astronauts from 19 countries have visited the ISS. Canada has been well represented. Marc Garneau, now a cabinet minister in the federal government and at one time president of the Canadian Space Agency, was our first astronaut and the first Canadian to visit the space station.
Canada’s Chris Hadfield became station commander and is arguably the most well-known ISS astronaut, particularly for his guitar performance of David Bowie’s Space Oddity. He flew on the Space Shuttle twice. He was the first Canadian to walk in space. He made extensive use of social media during his stay on the ISS and has some 2.3 million Twitter followers.
Julie Payette, Canada’s current Governor-General, was an astronaut on the 29th Shuttle mission to the ISS, particularly charged with operating the Shuttle’s Canadarm, the Space Station’s Canadarm2, and a special-purpose arm on the Japanese segment, Kibo.
A common misconception is that there is no gravity on the ISS. This is an extension of the misconception that in space, or beyond Earth’s atmosphere, there is no gravity. In fact, gravity at the altitude of the space station is not zero, but about 90 per cent of what it is here on the surface of our planet. It is the notion of free fall that leads to what we call weightlessness or microgravity.
Seeing the ISS from down here on terra firma is straightforward. You can sign up for email alerts from NASA, you can install one of many ISS apps on your mobile (I use ISS Detector), or you can use a site such as heavens-above.com or n2yo.com. All will tell you precisely when the ISS will be visible from your location.
Russian cosmonaut Valery Polyakov spent 437 days on the ISS. However, it was the stay of American astronaut Scott Kelly, who spent 340 days on board the ISS while fellow astronaut and twin brother Mark Kelly (recently elected to the U.S. Senate) remained on the ground, that made it possible to conduct groundbreaking research on the effects of space travel on the human body.
Changes were noted at the cell level in telomeres, cognitive changes measured by speed and accuracy were altered for up to six months, some carotid artery thickening was noticed, and we are learning more about vision problems associated with long-term space flight.
From time to time the ISS takes carefully planned evasive action because of space junk. Because of atmospheric drag, the ISS must regularly be boosted back into the top of its orbital altitude range. Even at an altitude of 400 km there is enough friction to cause the ISS to slow slightly, and hence drop slightly in altitude. Without corrective action from other craft that are docked with it the ISS would eventually crash back to earth.
The ISS operates under international agreements that are renewed from time to time. There is presently confusion over the long-term future of the ISS. Currently 2030 stands as a date for planned operations to end. Friction with Russia over sanctions regarding Crimea has stalled some negotiations.
With the U.S. demonstrating that it can again launch manned craft to the ISS, the Russians stand to lose significant revenue. There is talk of commercializing operations on the ISS. Actor Tom Cruise and a director are tentatively booked for an October 2021 launch for an as-yet untitled movie to be shot on the ISS.
It seems unlikely that the ISS will still be operational and crewed for another 20 years, but, then, 20 years ago who would have envisaged serious thought about landing on an asteroid, having two craft still reporting back from beyond the solar system, or a crewed mission to Mars? The first two of those three are accomplished, and thanks to two decades of experience on the ISS we have a good handle on what may be needed to get humans to the Red Planet.
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