In The Martian, Watney creates a large cylindrical space contained by clear plastic sheets, into which he dumps 126 square meters of Martian soil. To fertilise the potatoes, Watney turns to the only organic material present on Mars: human waste.
In the film, Damon's character, Mark Watney, who was an astro-botanist, ingeniously used faecal waste to fertilise his Martian garden. Billions and billions of bacteria call poop home-sweet-home. And that's exactly what Martian soil needs in order to sustain plant life—microbes.
Could you grow potatoes on Mars like in The Martian?
In the story, astronaut Mark Watney (played by Matt Damon in the movie), survives being stranded on Mars by growing potatoes—using his own feces for fertilizer. Now, a new experiment here on Earth has shown potato plants can actually grow in "near-martian" conditions.
In the story, Watney's botany skills help him survive the ordeal. He uses the potatoes NASA packed for his Mars expedition along with his own feces and manages to grow potatoes in a small farm inside the Hab. Also, his knowledge of chemistry allows him to make water, which he uses to irrigate the potatoes.
With no means of farmable materials on Mars, Watney uses potatoes, brought for the crew's thanksgiving meal, to create a potato farm, which he fertilizes with human feces, prolonging his life long enough for the anticipated rendezvous with his crew.
THE MARTIAN Clip - Planting Potatoes (2015) Matt Damon
How did they grow potatoes in space?
The potato seeds were placed inside the ISS' computer-controlled growth chambers. This facility has unique lighting technology, high-efficiency temperature, humidity controls, and automation technology. Therefore, it can produce minitubers, even without the labor-intensive handling method.
Airlock Breach. When Airlock 1 breached, causing a gaping hole in The Hab, the potatoes were freeze dried and the bacteria in the soil assumed dead. Because of this Mark was unable to grow any more potatoes and could only eat the ones he still had with him.
In the film “The Martian,” astronaut Mark Watney (Matt Damon) survives being stranded on the Red Planet by farming potatoes in Martian dirt fertilized with feces.
However, they don't contain much protein, which could lead to muscle wastage over time – so like Mark Watney in The Martian, anyone trying to survive on just potatoes would need to supplement them with vitamin and mineral supplements.
While most of the native potatoes died shortly after their roots entered the 'Martian' soil, a few of them and most of the LTVR clones managed to grow and produce potatoes. “It was a pleasant surprise to see that potatoes we have bred to tolerate abiotic stress were able to produce tubers in this soil,” Amoros said.
According to ESA, Mars' atmosphere is composed of 95.32% carbon dioxide, 2.7% nitrogen, 1.6% argon and 0.13% oxygen. The atmospheric pressure at the surface is 6.35 mbar which is over 100 times less Earth's. Humans therefore cannot breathe Martian air.
Mars is a planet with a very similar daily cycle to the Earth. Its sidereal day is 24 hours, 37 minutes and 22 seconds, and its solar day 24 hours, 39 minutes and 35 seconds. A Martian day (referred to as “sol”) is therefore approximately 40 minutes longer than a day on Earth.
In The Martian, Watney creates a large cylindrical space contained by clear plastic sheets, into which he dumps 126 square meters of Martian soil. To fertilise the potatoes, Watney turns to the only organic material present on Mars: human waste.
Potatoes always do best in full sun. They are aggressively rooting plants, and we find that they will produce the best crop when planted in a light, loose, well-drained soil.
Mars does have an atmosphere, but it is about 100 times thinner than Earth's atmosphere and it has very little oxygen. The atmosphere on Mars is made up of mainly carbon dioxide. An astronaut on Mars would not be able to breathe the Martian air and would need a spacesuit with oxygen to work outdoors.
Mars might not be somewhere we could live. We are not sure how effective Mars's atmosphere would be as a radiation shield (how will astronauts hide from radiation on Mars?) And we must remember that the explorers will have to spend a long time on the planet. There can be no quick there-and-back dash, as with the Moon.
The NASA Phoenix lander first detected chlorine-based compounds such as calcium perchlorate. The levels detected in the Martian soil are around 0.5%, which is a level considered toxic to humans. These compounds are also toxic to plants.
Potatoes are grown from special potatoes called “seed potatoes” which are cut into pieces (sometimes left whole) and planted in the ground. These pieces of potato grow stems and roots from the “eyes.” Because they are able to feed off the energy in the seed piece, potato plants grow very fast right from the start.
There is the plausible science (using rocket fuel as a source for water) and the downright impossible fiction (Mars sandstorms are not strong enough to cause damage. They're more like gentle breezes.). So while the overall Martian scenario may be fictional, the science in COLL 150 is very real.
But the scientists faced a steep challenge. Conditions on Mars are not hospitable to biological life. The planet's soils are salty, thin, and lacking in chemicals like nitrogen, which helps plants grow.
Firstly, as they are very hardy and adaptable plants, they can grow in different environmental conditions and can withstand extreme temperatures, humidity and other adversities. This means that they can survive in circumstances of low gravity and high radiation in space.
Astronauts can't bring bread and chips or alcohol to space. Bread expands, and chips have the ability to leave crumbs, which would cause problems in space (see below).
