And what does not work in space?
This week’s essay is an interesting one for me, because I had written this nearly 30 years ago and amazingly it still makes sense. So, in all these intervening years, hasn’t there been much progress or have I not kept up with developments? The latter may be one reason, but it is also true that by 1989, when this essay was written some basic and important knowledge was already there. And here it is (with some few minor pieces of information added). A former colleague of mine, Prof. Asashima, was one of the founders of the “Society of Space Biologists” in Japan. But what is space biology and what do space-biologists in contrast to exobiologists, who ponder about life on Mars, Ganymede and Europa moons, actually do?
Prior to the advent of spaceflight, this branch of biology was largely synonymous with “gravitational biology” (the study of the effects of gravitation on physiological and behavioural processes), but now it encompasses observations on microgravity effects on living organisms in space, the study of radiation outside the Earth’s atmosphere, the health and safety of astronauts. Not only animals, plants too, are surprisingly sensitive to gravity and experiments in space laboratories with seedlings have shown that root growth becomes disoriented, while shoot orientation responds mainly to the direction of light. Germination was not affected by space conditions and for short periods plants grew relatively normally.
However, many plants appear to have difficulties developing flowers and opening them in spaceflights. The one success space biologist have had was the fast growing Arabidopsis, the common wall cress. It even produced fertile seeds while on board a spacecraft. Another plant, an orchid, only produced leaves in 6 months, but returned to Earth quickly flowered. Aquatic algae that don’t have roots and grow in an aquatic environment as a suspension, do well even in space and might one day serve as a fresh food supply for astronauts.
When it comes to animals, space biologists have not yet reached a consensus on the practicalities of culturing them under space conditions. On the one hand, inflight fertilisations have not been documented (although rats would not be deterred by weightlessness and did mate in spaceflight) and there are warnings that, once initiated, development in space is likely to be abnormal for all but the smallest organism, because of the lack of gravity. Bones in humans are known to weaken during long space flights and effects on the visual sense and brain activities can also not be ruled. However, when fertilisations took place pre-flight on Earth and pre-natal development occurred partially during Cosmos 1514 flight, pups delivered postflight appeared normal morphologically as well as behaviourally. Prof. Asashima’s famous ‘space-newts’ (specimens of Cynops pyrrhogaster) and eggs also developed normal after their return to Earth, but exhibited ear-stone abnormalities in space. Fish larvae in space without food hardly moved at all, but they did survive as long as controls on Earth.
If possible effects of microgravity are not entirely clearcut, the risks of cosmic radiation during spaceflights to germ cells or embryos are even more obscure. That this must have been in the minds of those astronauts, both male and female, who had children following their space excursions would be well understood by all of those readers having or expecting children of their own.
© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2017.
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