Plants in space

From Wikipedia, the free encyclopedia

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]

History[edit]

Vegetable Production System for ISS being discussed

In the 2010s there was an increased desire for long-term space missions, which led to desire for space-based plant production as food for astronauts.[10] An example of this is vegetable production on the International Space Station in Earth orbit.[10] By the year 2010, 20 plant growth experiments had been conducted aboard the International Space Station.[1]

Several experiments have been focused on how plant growth and distribution compares in micro-gravity, space conditions versus Earth conditions. This enables scientists to explore whether certain plant growth patterns are innate or environmentally driven. For instance, Allan H. Brown tested seedling movements aboard the Space Shuttle Columbia in 1983. Sunflower seedling movements were recorded while in orbit. They observed that the seedlings still experienced rotational growth and circumnutation despite lack of gravity, showing these behaviors are instinctual.[11]

Other experiments have found that plants have the ability to exhibit gravitropism, even in low-gravity conditions. For instance, the ESA's European Modular Cultivation System[12] enables experimentation with plant growth; acting as a miniature greenhouse, scientists aboard the International Space Station can investigate how plants react in variable-gravity conditions. The Gravi-1 experiment (2008) utilized the EMCS to study lentil seedling growth and amyloplast movement on the calcium-dependent pathways.[13] The results of this experiment found that the plants were able to sense the direction of gravity even at very low levels.[14] A later experiment with the EMCS placed 768 lentil seedlings in a centrifuge to stimulate various gravitational changes; this experiment, Gravi-2 (2014), displayed that plants change calcium signalling towards root growth while being grown in several gravity levels.[15]

Many experiments have a more generalized approach in observing overall plant growth patterns as opposed to one specific growth behavior. One such experiment from the Canadian Space Agency, for example, found that white spruce seedlings grew differently in the anti-gravity space environment compared with Earth-bound seedlings;[16] the space seedlings exhibited enhanced growth from the shoots and needles, and also had randomized amyloplast distribution compared with the Earth-bound control group.[17]

Food production is key to making Space exploration feasible. Currently, the cost of sending food to the International Space Station (ISS) is estimated as USD$20 000–40 000/kg, with each crew member receiving ~1.8 kg of food (plus packaging) per day . Re-stocking from Earth, a lunar orbiting Space station or Mars habitation with food will be significantly more costly. The first trips to Mars are expected to be a three-year round trip, and it has been estimated that a four-person crew would need 10–11 000 kgs of food.[18]

Early efforts[edit]

The first organisms in space were "specially developed strains of seeds" launched to 134 km (83 mi) on 9 July 1946 on a U.S. launched V-2 rocket. These samples were not recovered. The first seeds launched into space and successfully recovered were maize seeds launched on 30 July 1946. Soon followed rye and cotton. These early suborbital biological experiments were handled by Harvard University and the Naval Research Laboratory and were concerned with radiation exposure on living tissue.[19] On September 22 1966, Kosmos 110 launched with two dogs and moisturized seeds. Several of those seeds germinated, the first to do so, resulting in lettuce, cabbage and some beans that had greater yield than their controls on Earth.[20] In 1971, 500 tree seeds (Loblolly pine, Sycamore, Sweetgum, Redwood, and Douglas fir) were flown around the Moon on Apollo 14. These Moon trees were planted and grown with controls back on Earth where no changes were detected.

Space station era[edit]

The arugula-like lettuce Mizuna growing for Veg-03
A young sunflower plant aboard the ISS[21]

In 1982, the crew of the Soviet Salyut 7 space station conducted an experiment, prepared by Lithuanian scientists (Alfonsas Merkys and others), and grew some Arabidopsis using Fiton-3 experimental micro-greenhouse apparatus, thus becoming the first plants to flower and produce seeds in space.[22][23] A Skylab experiment studied the effects of gravity and light on rice plants.[24][25] The SVET-2 Space Greenhouse successfully achieved seed to seed plant growth in 1997 aboard space station Mir.[3] Bion 5 carried Daucus carota and Bion 7 carried maize (aka corn).

Plant research continued on the International Space Station. Biomass Production System was used on the ISS Expedition 4. The Vegetable Production System (Veggie) system was later used aboard ISS.[26] Plants tested in Veggie before going into space included lettuce, Swiss chard, radishes, Chinese cabbage and peas.[27] Red Romaine lettuce was grown in space on Expedition 40 which were harvested when mature, frozen and tested back on Earth. Expedition 44 members became the first American astronauts to eat plants grown in space on 10 August 2015, when their crop of Red Romaine was harvested.[28] Since 2003 Russian cosmonauts have been eating half of their crop while the other half goes towards further research.[29] In 2012, a sunflower bloomed aboard the ISS under the care of NASA astronaut Donald Pettit.[30] In January 2016, US astronauts announced that a zinnia had blossomed aboard the ISS.[31]

In 2017 the Advanced Plant Habitat was designed for ISS, which was a nearly self-sustaining plant growth system for that space station in low Earth orbit.[32] The system is installed in parallel with another plant grown system aboard the station, VEGGIE, and a major difference with that system is that APH is designed to need less upkeep by humans.[32] APH is supported by the Plant Habitat Avionics Real-Time Manager.[32] Some plants that were to be tested in APH include Dwarf Wheat and Arabidopsis.[32] In December 2017 hundreds of seeds were delivered to ISS for growth in the VEGGIE system.[33]

In 2018 the Veggie-3 experiment at the ISS, was tested with plant pillows and root mats.[34] One of the goals is to grow food for crew consumption.[34] Crops tested at this time include cabbage, lettuce, and mizuna.[34] In 2018, the PONDS system for nutrient deliver in microgravity was tested.[35]

Interior view of a hypothetical O'Neill cylinder space habitat, showing alternating land and window stripes.

In December 2018, the German Aerospace Center launched the EuCROPIS satellite into low Earth orbit. This mission carries two greenhouses intended to grow tomatoes under simulated gravity of first the Moon and then Mars (6 months each) using by-products of human presence in space as source of nutrients.[citation needed][needs update]

The Seedling Growth series of experiments to study the mechanisms of tropisms and the cell/cycle were performed on the ISS between 2013 and 2017.[36][37] These experiments also involved using the model plant Arabidopsis thaliana, and were a collaboration between NASA (John Z. Kiss as PI) and ESA (F. Javier Medina as PI).[38][37]

On 30 November 2020, astronauts aboard the ISS collected the first harvest of radishes grown on the station. A total of 20 plants was collected and prepared for transportation back to Earth. There are currently plans to repeat the experiment and grow a second batch.[39]

Lunar surface[edit]

Chang'e 4 lunar lander in January 2019, carried a 3 kg (6.6 lb) sealed "biosphere" with many seeds and insect eggs to test whether plants and insects could hatch and grow together in synergy.[40] The experiment included seeds of potatoes, tomatoes, and Arabidopsis thaliana (a flowering plant), as well as silkworm eggs. These became[citation needed] the first plants grown on the Moon. Environmental systems will keep the container hospitable and Earth-like, except for the low lunar gravity.[41] If the eggs hatch, the larvae would produce carbon dioxide, while the germinated plants would release oxygen through photosynthesis. It is hoped that together, the plants and silkworms can establish a simple synergy within the container. A miniature camera will photograph any growth. The biological experiment was designed by 28 Chinese universities.[42][needs update][43]

Lunar soil has also been proven to allow plants to grow on, tested in a laboratory at the University of Florida.[44] These experiments showed that while the plant Arabidopsis thaliana can germinate and grow in lunar soil, that there are challenges presented in the plants ability to thrive, as many were slow to develop. Plants that did germinate showed morphological and transcriptomic indications of stress.[45]

Plants grown in space[edit]

Lettuce grown in space aboard the ISS

Plants grown in space include:

Experiments[edit]

Illustration of plants growing in a hypothetical Mars base.

Some experiments involving plants include:

  • Advanced Plant Habitat, began April 2017 aboard the ISS.[52]
  • Bion satellites, began 1973.
  • Biomass Production System, began April 2002, aboard the ISS.[53]
  • Vegetable Production System (Veggie), began May 2014 aboard the ISS.[54]
  • SVET, began June 1990 aboard Mir.[55]
  • SVET-2, was conducted in 1997 aboard Mir.[56]
  • Lada greenhouse (aka Lada Validating Vegetable Production Unit), began 2002, aboard the ISS.[1]
  • ADVASC, aboard the ISS and Mir.[57]
  • TAGES, began November 2009 aboard the ISS.[58][59]
  • Plant Growth/Plant Phototropism, selected March 1972 aboard Skylab.[60]
  • Oasis plant growth unit, began 1971 aboard the Salyut 1.[61]
  • Space Rose (STS-95), to evaluate the effects of microgravity on the production of aroma constituents, a rose plant with both an unopened bud and a half bloom was sent into the space aboard NASA space shuttle STS-95 for 9 days, from October 29 through November 6, 1998.[62]
  • Plant Signaling (STS-135), began July 2011 aboard the ISS.[63]
  • Plant growth experiment (STS-95), began October 1998 aboard the ISS.[64]
  • NASA Clean Air Study, began in 1989 at the Stennis Space Center.[65]
  • ECOSTRESS, began June 2018 aboard the ISS.[66][67]
  • Chang'e 4 lunar lander "biosphere" with seeds and insect eggs to test whether plants and insects could hatch and grow together in synergy, began 2019.[40]
  • SpaceMoss (SpaceX CRS-18), a NASA experiment studying the growth of the moss Physcomitrella patens in microgravity, began July 2019 aboard the ISS.[68]
  • Algae as sustainable food in space[69][70]

See also[edit]

References[edit]

  1. ^ a b c d e f "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 c d e f T. Ivanova; et al. "First Successful Space Seed-to-Seed Plant Growth Experiment in the SVET-2 Space Greenhouse in 1997" (PDF). Space.bas.bg. Retrieved 13 February 2019.
  4. ^ a b "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.
  10. ^ a b Rainey, Kristine (2 March 2015). "Veggie will Expand Fresh Food Production on Space Station". NASA. Retrieved 13 February 2019.
  11. ^ Chamovitz, Daniel (2012). What a plant knows : a field guide to the senses (1st ed.). New York: Scientific American/Farrar, Straus and Giroux. ISBN 978-0-374-28873-0.
  12. ^ Jost, Ann-Iren Kittang; Hoson, Takayuki; Iversen, Tor-Henning (20 January 2015). "The Utilization of Plant Facilities on the International Space Station—The Composition, Growth, and Development of Plant Cell Walls under Microgravity Conditions". Plants. 4 (1): 44–62. doi:10.3390/plants4010044. ISSN 2223-7747. PMC 4844336. PMID 27135317.
  13. ^ Driss-Ecole, Dominique; Legué, Valérie; Carnero-Diaz, Eugénie; Perbal, Gérald (1 September 2008). "Gravisensitivity and automorphogenesis of lentil seedling roots grown on board the International Space Station". Physiologia Plantarum. 134 (1): 191–201. doi:10.1111/j.1399-3054.2008.01121.x. ISSN 1399-3054. PMID 18429941.
  14. ^ "Scientific objectives". Lensesinspace.wordpress.com. 28 March 2014.
  15. ^ European Space Agency (5 July 2016). "A decade of plant biology in space". Phys.org.
  16. ^ "Advanced Plant Experiment - Canadian Space Agency 2 (APEX-CSA2)". NASA.
  17. ^ Rioux, Danny; Lagacé, Marie; Cohen, Luchino Y.; Beaulieu, Jean (1 January 2015). "Variation in stem morphology and movement of amyloplasts in white spruce grown in the weightless environment of the International Space Station". Life Sciences in Space Research. 4: 67–78. Bibcode:2015LSSR....4...67R. doi:10.1016/j.lssr.2015.01.004. PMID 26177622.
  18. ^ Mortimer, Jenny C.; Gilliham, Matthew (1 February 2022). "SpaceHort: redesigning plants to support space exploration and on-earth sustainability". Current Opinion in Biotechnology. 73: 246–252. doi:10.1016/j.copbio.2021.08.018. ISSN 0958-1669. PMID 34563931. S2CID 237941352.
  19. ^ Beischer, DE; Fregly, AR (1 January 1962). Animals and man in space. A chronology and annotated bibliography through the year 1960 (Report). US Naval School of Aviation Medicine. Retrieved 5 November 2022.
  20. ^ Brian Harvey; Olga Zakutnyaya (2011). Russian Space Probes: Scientific Discoveries and Future Missions. Springer Science & Business Media. p. 315. ISBN 978-1-4419-8150-9.
  21. ^ a b "Photo-iss038e000734". NASA. Archived from the original on 21 April 2014. Retrieved 13 February 2019.
  22. ^ "First species of plant to flower in space". Guinness World Records. Retrieved 20 January 2016.
  23. ^ Cowing, Keith (16 January 2016). "No NASA, These Are Not The First Plants To Flower In Space". NASA Watch. Retrieved 20 January 2016.
  24. ^ a b "0102081 - Plant Growth/Plant Phototropism - Skylab Student Experiment ED-61/62". NASA. Archived from the original on 17 March 2016. Retrieved 13 February 2019.
  25. ^ Summerlin, L. B. (January 1977). "SP-401 Skylab, Classroom in Space -- Chapter 5: Embryo Development in Space". NASA History. Retrieved 13 February 2019.
  26. ^ "Vegetable Production System". NASA. Archived from the original on 23 November 2010. Retrieved 13 February 2019.
  27. ^ Regan, Rebecca (16 October 2012). "Station Investigation to Test Fresh Food Experience". NASA. Archived from the original on 23 January 2016. Retrieved 23 January 2016.
  28. ^ Kluger, Jeffrey (10 August 2015). "Why Salad in Space Matters". Time.
  29. ^ Bauman, Joe (16 June 2003). "USU Experiment Feeds Astronauts' Minds, Taste Buds". Deseret News. Space Dynamics Laboratory. Archived from the original on 14 February 2019. Retrieved 28 August 2015.
  30. ^ "June 17–26 – Diary of a Space Zucchini". Letters to Earth: Astronaut Don Pettit (NASA Blogs). 29 June 2012. Retrieved 20 January 2016.
  31. ^ Kooser, Amanda (18 January 2016). "Behold the first flower to bloom in space, a cheerful zinnia". CNET.
  32. ^ a b c d Herridge, Linda (2 March 2017). "New Plant Habitat Will Increase Harvest on International Space Station". NASA. Retrieved 11 May 2018.
  33. ^ "Zero gravity plant growth experiments delivered to space station". EurekAlert. 18 December 2017. Retrieved 11 May 2018.
  34. ^ a b c d "NASA Space Station On-Orbit Status 6 February 2018 - Celebrating 10 Years of ESA's Columbus Module". SpaceRef. Archived from the original on 1 October 2021. Retrieved 8 February 2018.
  35. ^ "NASA - Veggie PONDS". NASA. Retrieved 13 February 2019.
  36. ^ Vandenbrink, Joshua P.; Herranz, Raul; Medina, F. Javier; Edelmann, Richard E.; Kiss, John Z. (1 December 2016). "A novel blue-light phototropic response is revealed in roots of Arabidopsis thaliana in microgravity". Planta. 244 (6): 1201–1215. Bibcode:2016Plant.244.1201V. doi:10.1007/s00425-016-2581-8. ISSN 1432-2048. PMC 5748516. PMID 27507239.
  37. ^ a b Kovo, Yael (11 May 2017). "Seedling Growth-3 (SpaceX-11)". NASA. Retrieved 26 October 2020.
  38. ^ "To Boldly Grow". UNCG Research Magazine. Retrieved 26 October 2020.
  39. ^ Herridge, Linda (2 December 2020). "Astronauts Harvest First Radish Crop on International Space Station". NASA. Retrieved 6 December 2020.
  40. ^ a b David, Leonard (22 May 2018). "Comsat Launch Bolsters China's Dreams for Landing on the Moon's Far Side". Scientific American. Archived from the original on 29 November 2018.
  41. ^ Tayag, Yasmin (2 January 2019). "China Is About to Land Living Eggs on the Far Side of the Moon". Inverse.
  42. ^ Rincon, Paul (2 January 2019). "Chang'e-4: China mission primed for landing on Moon's far side". BBC News.
  43. ^ Massa, G.D.; Wheeler, R.M.; Morrow, R.C.; Levine, H.G. (2016). "Growth chambers on the International Space Station for large plants". Acta Horticulturae (1134): 215–222. doi:10.17660/ActaHortic.2016.1134.29. hdl:2060/20160006558. ISSN 0567-7572. S2CID 132103806.
  44. ^ Keeter, Bill (12 May 2022). "Scientists Grow Plants in Lunar Soil". NASA. Retrieved 16 August 2023.
  45. ^ Paul, Anna-Lisa; Elardo, Stephen M.; Ferl, Robert (12 May 2022). "Plants grown in Apollo lunar regolith present stress-associated transcriptomes that inform prospects for lunar exploration". Communications Biology. 5 (1): 382. doi:10.1038/s42003-022-03334-8. ISSN 2399-3642. PMC 9098553. PMID 35552509.
  46. ^ a b c d e Zimmerman, Robert (September 2003). "Growing Pains". Air & Space Magazine. Retrieved 13 February 2019.
  47. ^ Griffin, Amanda (17 February 2017). "Cabbage Patch: Fifth Crop Harvested Aboard Space Station". NASA. Archived from the original on 23 April 2019. Retrieved 28 March 2017.
  48. ^ "NASA - A Plant Growth Chamber". NASA. Archived from the original on 8 August 2020. Retrieved 13 February 2019.
  49. ^ Dean, James (29 December 2015). "ISS space flowers may need some help from 'Martian'". Florida Today. Retrieved 19 April 2017.
  50. ^ Smith, Steve (10 August 2015). "'Outredgeous' Red Romaine Lettuce, Grown Aboard The International Space Station, To Be Taste-Tested By Astronauts". Medical Daily. Pulse. Retrieved 19 April 2017.
  51. ^ Salmi, Mari L.; Roux, Stanley J. (1 December 2008). "Gene expression changes induced by space flight in single-cells of the fern Ceratopteris richardii". Planta. 229 (1): 151–159. Bibcode:2008Plant.229..151S. doi:10.1007/s00425-008-0817-y. PMID 18807069. S2CID 30624362.
  52. ^ "NASA - Advanced Plant Habitat". NASA. Retrieved 13 February 2019.
  53. ^ "NASA - Biomass Production System (BPS) fact sheet". www.nasa.gov. Retrieved 16 October 2022.
  54. ^ Heiney, Anna (9 April 2019). "Growing Plants in Space". NASA. Retrieved 16 October 2022.
  55. ^ Ivanova, T. N.; Bercovich YuA, null; Mashinskiy, A. L.; Meleshko, G. I. (1 August 1993). "The first "space" vegetables have been grown in the "SVET" greenhouse using controlled environmental conditions". Acta Astronautica. 29 (8): 639–644. Bibcode:1993AcAau..29..639I. doi:10.1016/0094-5765(93)90082-8. ISSN 0094-5765. PMID 11541646.
  56. ^ Ivanova, Tanya; Sapunova, Svetlana; Kostov, Plamen; Dandolov, Ivan (1 January 2001). "First successful space seed-to-seed plant growth experiment in the SVET-2 Space Greenhouse in 1997". Aerospace Research in Bulgaria. 16: 12–23. Bibcode:2001ARBl...16...12I. ISSN 0861-1432.
  57. ^ "NASA - ADVANCED ASTROCULTURE (ADVASC) fact sheet (11/01)". www.nasa.gov. Retrieved 16 October 2022.
  58. ^ Phillips, Tony (6 May 2013). "Glow-in-the-Dark Plants on the ISS". NASA Science. Archived from the original on 8 January 2020. Retrieved 13 February 2019.
  59. ^ Administrator, NASA (7 June 2013). "Getting to The Root of Plant Growth Aboard The Space Station". NASA. Archived from the original on 23 April 2019. Retrieved 16 October 2022.
  60. ^ NASA/Marshall Space Flight Center (1 January 1973), Plant Growth/Plant Phototropism - Skylab Student Experiment ED-61/62, retrieved 16 October 2022
  61. ^ "Oasis Series Growth Chambers | astrobotany.com". 21 November 2020. Retrieved 16 October 2022.
  62. ^ "Space Rose Pleases the Senses". Spinoff 2002. January 2002.
  63. ^ Kovo, Yael (23 February 2015). "Plant Signaling (STS-135)". NASA. Retrieved 16 October 2022.
  64. ^ Ueda, J.; Miyamoto, K.; Yuda, T.; Hoshino, T.; Sato, K.; Fujii, S.; Kamigaichi, S.; Izumi, R.; Ishioka, N.; Aizawa, S.; Yoshizaki, I.; Shimazu, T.; Fukui, K. (June 2000). "STS-95 space experiment for plant growth and development, and auxin polar transport". Uchu Seibutsu Kagaku. 14 (2): 47–57. doi:10.2187/bss.14.47. ISSN 0914-9201. PMID 11543421. S2CID 35765388.
  65. ^ Wolverton, B. C.; Johnson, Anne; Bounds, Keith (15 September 1989). Interior Landscape Plants for Indoor Air Pollution Abatement (Report).
  66. ^ "ECOSTRESS". NASA Jet Propulsion Laboratory (JPL). Retrieved 5 November 2022.
  67. ^ NASA's New Space 'Botanist' Arrives at Launch Site. NASA. 17 April 2018.
  68. ^ "Environmental Response and Utilization of Mosses in Space – Space Moss". NASA. Retrieved 25 July 2019.
  69. ^ Vinayak, Vandana (1 January 2022), Varjani, Sunita; Pandey, Ashok; Bhaskar, Thallada; Mohan, S. Venkata (eds.), "Chapter 20 - Algae as sustainable food in space missions", Biomass, Biofuels, Biochemicals, Elsevier, pp. 517–540, doi:10.1016/b978-0-323-89855-3.00018-2, ISBN 978-0-323-89855-3, retrieved 26 June 2022
  70. ^ Halstead, T W; Dutcher, F R (June 1987). "Plants in Space". Annual Review of Plant Physiology. 38 (1): 317–345. doi:10.1146/annurev.pp.38.060187.001533. ISSN 0066-4294. PMID 11538459.

External links[edit]