How to grow plants 400km above the ground

Quora is a site for post­ing ques­tions to the inter­net. Sometimes those ques­tions get answer. For example Robert Frost, who has trained astro­nauts for the International Space Station, has answered the ques­tion: How are plants grow­ing in the ISS?

Gravity is not the only dif­fer­ence between the Earth envir­on­ment and the ISS envir­on­ment. In the closed atmo­sphere of a space­craft, volat­ile organic com­pounds (VOCs) can accu­mu­late. VOCs need to be scrubbed from the air or seed pro­duc­tion will suf­fer. There are elev­ated radi­ation levels that can cause muta­tions and affect growth. An exper­i­ment on Mir, that involved stor­ing tomato seeds in space for six years found muta­tion rates up to 20 times higher in the space seeds than in the con­trol seeds stored on the ground. And there are the spec­tral effects of using only elec­tric lighting.

Plant in space

An auto­trophic astro­naut. Photo: NASA.

Because plants also respire, we have to have fans to cir­cu­late the air around the plants so that they don’t suf­foc­ate on their own exhal­a­tions. Even failed exper­i­ments can provide us with bet­ter under­stand­ing. An exper­i­ment to study plant lignin failed to pro­duce healthy plant mater­i­als but taught us more about provid­ing effect­ive air movement.

You can read more at Quora.

Alun Salt. ORCID 0000-0002-1261-4283

When he's not the web developer for AoB Blog, Alun Salt researches something that could be mistaken for the archaeology of science. His current research is about whether there's such a thing as scientific heritage and if there is how would you recognise it?

1 Response

  1. In fact, I think some of the most up-to-date and cur­rent, rig­or­ous, research on plants in space was pub­lished no less than 30 years ago in Annals of Botany: http://​aob​.oxford​journ​als​.org/​c​o​n​t​e​n​t​/​5​4​/​s​u​p​p​3​.​toc Annals of Botany 54: sup­ple­ment 3, November 1984. Most sub­sequent work has been car­ried out in rather sub-optimal con­di­tions, con­trols (ie a ground-based identical cap­sule, includ­ing atmo­sphere control/lots of plastics/hot elec­tron­ics etc. as in orbit — this is poin­ted out in the blog com­ment­ary above) are not­ably often lack­ing, and inter­pret­a­tion heads towards the gung-ho rather than world-class science.

    As my father wrote in the Introduction to the 1984 issue, “The papers in this Supplement provide a com­pre­hens­ive con­spectus of the research on plants under the con­di­tions of space flight con­duc­ted in recent years under the aus­pices of the US National Aeronautics and Space Administration NASA, and in addi­tion they offer doc­u­mented reviews of the par­al­lel work on plants car­ried out in the course of the Soviet space-flight pro­gramme. Collectively they are unique in provid­ing, for the first time, ready access for bot­an­ists to the res­ults from an area of research many have regarded as eso­teric and out­side their range of interests — and the lit­er­at­ure of which has, in any event, been largely out of reach except for those actu­ally in the field.

    “Perhaps one has to con­cede that the pro­gramme of botan­ical research so far has been no more than mod­estly inform­at­ive, as Halstead and Dutcher remark in their intro­duct­ory paper. Yet with the bur­geon­ing appre­ci­ation of how import­ant it now is
    to gain a bet­ter under­stand­ing of how plants react to micro­grav­ity, and the other spe­cial con­di­tions of space-flight, and with the great improve­ment of exper­i­mental facil­it­ies likely to become avail­able with the next gen­er­a­tion of space­craft, an explos­ive increase in research effort in the next dec­ade may con­fid­ently be expec­ted. For this to be dir­ec­ted towards the most reward­ing tar­gets, it is vital that a broad spec­trum of plant sci­ent­ists should be aware of the oppor­tun­it­ies, and that those with spe­cially per­tin­ent expert­ise should be avail­able for con­sulta­tion and advice. It is for these reas­ons that the Annals of Botany Company have wel­comed the oppor­tun­ity of pub­lish­ing this Supplement, in the know­ledge that it will reach a wide range of bot­an­ists, and with the hope that it will stim­u­late many to con­sider how they might con­trib­ute in the new endeavour.”