In August last year, lettuce became a hero. According to foreign media reports, on August 11, astronauts living in the International Space Station tasted the lettuce they planted in space for the first time. Scientists see the taste on the tip of the tongue as an important step in the manned spacecraft to Mars. The lettuce that grew up in the space station made the NASA astronauts feel very unusual. The red lettuce, which was grown this time, was sent to the space station by the former “Dragon” spacecraft, which was grown in a special “vegetable box” designed by the Madison Track Technology Center in Wisconsin, USA.
The seeds of the lettuce are sprinkled on a mat for rooting and germination, and the mat consists of soil and fertilizer. Since water cannot be watered in space, a special irrigation system is designed at the bottom of the mat. Each “vegetable box” weighs about 7 kg and can be folded or stretched. The box is also equipped with red, green and blue LED lights to promote vegetable growth.
NASA said that since May 2014, the International Space Station has begun experimenting with growing vegetables. If astronauts exploring space can grow their own vegetables after flying off the earth, they may be better able to cope with the harsh space exploration. And these expeditions will take months or even years. The possibility of providing regular supplies to Mars does not exist. Astronauts who want to survive on the voyage must plant their own food.
As technology continues to advance, planting some plants in space has been very efficient. Currently, scientists are studying the cultivation of a genetically modified dwarf plum tree that is only about 2 meters in space. However, protein, fat and carbohydrates may require more diverse sources such as tomatoes and peanuts.
But if the water runs out, all these efforts will be squandered. On the International Space Station, the urinary-water recovery system requires regular repairs, and astronauts performing inter-stellar missions cannot regain new parts. In this case, GMOs may work. Michael Flynn, an engineer at the NASA Arms Research Center, is working on a water filter made up of genetically modified bacteria that works like a human small intestine to reclaim something. Flynn said: "Basically, the human body with a life span of 75 to 80 years old is itself a water recycling system." This filtering device, like the human internal organs, may continue to be self-sufficient.