From artificial retinas to ageing mice, here are five of the most promising results from research performed on the ISS – and what they might mean for humans on Earth and in space.
It’s not all eating bits of food floating in mid-air and introducing suction toilets to fascinated Earthlings – crews on the International Space Station (ISS), which will be coming to an end soon, have serious work to do.
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| NASA |
Since the station’s inception, astronauts and cosmonauts have performed more than 3000 experiments in the microgravity and heightened radiation of low-Earth orbit. These have ranged from confirming that fertility levels remain unaltered (in mice, not crew members) to testing the prospects of using lunar soil to make concrete to help build future moon bases. Here are four more of the most impressive bits of ISS research.
Artificial retinas
For millions of people with degenerative conditions affecting the retina – the layer of light-sensitive cells at the back of the eye – there is no cure, only treatments that slow progression. However, an implant that mimics the function of the retina might be the solution, and US-based company LambdaVision has had some success making one by depositing layer upon layer of a light-activated protein known as bacteriorhodopsin. On Earth, solutions of it tended to clump together, leading to poor deposition, but much better results came early this decade in the microgravity aboard the ISS. LambdaVision is now trying to scale up space manufacturing of the artificial retinas and claims these are among the first technologies evaluated on the ISS that have the potential for clinical use.
Invisible flames
When you light a match, the wood burns, reacting with oxygen to produce heat and light, as well as some other products such as carbon dioxide, water vapour and ash. Colder, heavier air sinks into the flame under gravity, thereby sustaining the oxygen supply. Aboard the ISS, flames look rather different. With little gravity, oxygen can only diffuse into the flames, so they spread gradually and persist for much longer – indeed, even after they appear to die out. In experiments beginning in 2009, ISS researchers discovered that these invisible flames continue to burn, but at relatively cool temperatures of 200°C to 500°C. The hope is that they can be recreated on Earth in different conditions, possibly for burning diesel in engines more efficiently and without generating the pollutants associated with higher-temperature combustion.
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| The top row shows a flame growing on the International Space Station, while the bottom row shows it going out NASA |
The ageing process
Living in secluded microgravity, astronauts lose muscle mass and bone density and their immune systems deteriorate – almost as though they were going through an accelerated ageing process. Several experiments on the ISS exploit this phenomenon to understand ageing in rodents, with the prospect of developing technologies to stall its effects in humans. These include hardware to measure bone density, map the function of the immune system, explore the structure of the blood-brain barrier and chart liver metabolism. Although no applications directly stemming from this ISS research have yet been publicised, the hope is that the data will feed into the development of advanced treatments for diseases like osteoporosis, muscular dystrophy, cancer and kidney failure.
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| Setting up an experiment on the International Space Station NASA |
Biomining
Rare earth metals are vital to modern technologies such as smartphones and electric cars. On Earth, microbes can be used to extract these elements. They release compounds into rocks that dissolve the metals, but scientists assumed that gravity was integral to the process. In 2020, however, researchers published data from the ISS demonstrating that at least one microbe, Sphingomonas desiccabilis, can leach rare earth elements just as well in microgravity as it can on Earth. The results suggest that biomining could be a way to harvest materials for human settlements on lunar or Martian bases so they don’t need to be transported there.
Video courtesy : NewScientist