ISS astronauts had maybe not imagined to have a living, non-human company in the Space Station. Enter Drosophila Melanogaster, better known as the Fruit Fly, already famous for having been the first Earthling ever sent to space by the United States in 1947, with a short suborbital V2 flight. It is now official that Fruit Fly Lab-O1 will fly to the ISS with the 5th SpaceX cargo run, and flies will become a permanent addition to the station.
Another fundamental thing is that all of these flies present exactly the same DNA sequence. Immune system studies of human astronauts can be affected by their own generic code, but this variable does not count for the flies. And they reproduce quite fast. Soon they are going to provide scientists with a huge sample, possibly across a range of conditions. It can be imagined to study them in Lower Earth Orbit conditions – the one targeted by Virgin Galactic flights – in MEO, where the ISS itself is positioned, and further away.
There are already evidence of how space permanence affect living being, flies included. For example, when Fruit Flies were sent to Earth orbit onboard Space Shuttle Discovery in 2006, they all experienced a decrement in their immune function, no matter if their stay was fairly short (only 13 days). The ISS experiment will provide many precious indications over a quite longer period. The flies will be living in a special Fruit Fly Lab, “and experiencing the same space radiation and microgravity as their human counterparts. Cameras will record the behavior and appearance of these miniature astronauts; and at intervals some of them will be frozen and returned to Earth for analysis.” (NASA Science, 8 July 2014).
“What we don’t realize in our everyday lives is that every biological, chemical and physical process that takes place in our terrestrial environment of Earth happens under the influence of gravitational forces. Conducting scientific investigations on the space station, such as that on the fruit flies, allows us to remove that gravitational element from the equation, and advances our knowledge about these same processes that lead to amazing breakthroughs and discoveries.” (Camille Alleyne, NASA’s Johnson Space Center, 1 July 2014)
But why this tiny insect has been single out for space experiments? For a very good reason indeed: it shares genes with humans – lots of them. About 77% of known human disease genes have a recognizable match in the genetic code of fruit flies, which have been completely sequenced. And up to 50% of fly proteins have some type of mammalian analogues, making it a perfect subject for the experiment.
Life in Space
“We can learn so much translationally from a simple model system. It’s a simple organism that pretty much mirrors a lot of the important functions of humans.” Sharmila Bhattacharya, Biomodel Performance Laboratory, NASA Ames Research Center.
Incidentally, flies are not the only ones studied at the moment. In a curious and much-discussed experiment, still ongoing, Russians are trying to study mating in zero-gravity, with five geckos currently in orbit (bad news about losing contact with the capsule have been proven wrong, and everything seems back under control). If sex in Zero-G, portrayed in many SF outlets, is something worth considering, we might have to examine them once (hopefully) back on land.
Still a lot of things remain unclear regarding the real possibility of human adaptation in space, an extreme environment in many ways comparable to deep sea and other hostile habitats. Many experiments are currently being performed to recreate living conditions on Mars, for instance, testing the possibility for human colonisation of the Red Planet. But more studies are necessary to understand how things like duration spaceflight, exposure to radiation, and microgravity can adversely affect humans – and fruit-flies will certainly give some answers.