Plants in space

Zinnia plant in bloom aboard an Earth orbiting space station

The growth of plants in outer space has elicited much scientific interest.[1] In the late 20th and early 21st century, plants were often taken into space in low Earth orbit to be grown in a weightless but pressurized controlled environment, sometimes called space gardens.[1] In the context of human spaceflight, they can be consumed as food and provide a refreshing atmosphere.[2] Plants can metabolize carbon dioxide in the air to produce valuable oxygen, and can help control cabin humidity.[3] Growing plants in space may provide a psychological benefit to human spaceflight crews.[3] Usually the plants were part of studies or technical development to further develop space gardens or conduct science experiments.[1] To date plants taken into space have had mostly scientific interest, with only limited contributions to the functionality of the spacecraft, however the Apollo Moon tree project was more or less forestry inspired mission and the trees are part of a country's bicentennial celebration.

The first challenge in growing plants in space is how to get plants to grow without gravity.[4] This runs into difficulties regarding the effects of gravity on root development, soil integration, and watering without gravity, providing appropriate types of lighting, and other challenges. In particular, the nutrient supply to root as well as the nutrient biogeochemical cycles, and the microbiological interactions in soil-based substrates are particularly complex, but have been shown to make possible space farming in hypo- and micro-gravity.[5][6]

NASA plans to grow plants in space to help feed astronauts and to provide psychological benefits for long-term space flight.[7] In 2017, aboard ISS in one plant growth device, the 5th crop of Chinese cabbage (Brassica rapa) from it included an allotment for crew consumption, while the rest was saved for study.[8] An early discussion of plants in space, were the trees on the brick moon space station, in the 1869 short story "The Brick Moon".[9]

  1. ^ a b c "NASA - Growing Plants and Vegetables in Space Garden". NASA. 15 June 2010. Retrieved 13 February 2019.
  2. ^ Wild, Flint (24 June 2013). "Plants in Space". NASA. Archived from the original on 23 April 2019. Retrieved 13 February 2019.
  3. ^ a b Cite error: The named reference zvet was invoked but never defined (see the help page).
  4. ^ "Getting to The Root of Plant Growth Aboard The Space Station". NASA. 7 June 2013. Archived from the original on 23 April 2019. Retrieved 13 February 2019.
  5. ^ Maggi, Federico; Pallud, Céline (2010). "Martian base agriculture: The effect of low gravity on water flow, nutrient cycles, and microbial biomass dynamics". Advances in Space Research. 46 (10): 1257–1265. Bibcode:2010AdSpR..46.1257M. doi:10.1016/j.asr.2010.07.012. ISSN 0273-1177.
  6. ^ Maggi, Federico; Pallud, Céline (2010). "Space agriculture in micro- and hypo-gravity: A comparative study of soil hydraulics and biogeochemistry in a cropping unit on Earth, Mars, the Moon and the space station". Planetary and Space Science. 58 (14–15): 1996–2007. Bibcode:2010P&SS...58.1996M. doi:10.1016/j.pss.2010.09.025. ISSN 0032-0633.
  7. ^ Rainey, Kristine (7 August 2015). "Crew Members Sample Leafy Greens Grown on Space Station". NASA. Archived from the original on 8 April 2019. Retrieved 23 January 2016.
  8. ^ Heiney, Anna (17 February 2017). "Cabbage Patch: Fifth Crop Harvested Aboard Space Station". NASA. Archived from the original on 23 April 2019. Retrieved 11 May 2018.
  9. ^ Hale, Edward Everett (December 1869). "The Brick Moon". The Atlantic Monthly. Vol. 24, no. 146. pp. 679–688. Retrieved 13 February 2019.