A lot of research has been conducted to see the viability of sending humans to make settlements in space. There are a few essentials that need to be taken into consideration. Food will be the most critical however, at the moment, we don't have the technology to produce a variety of food in space. So that's where NASA's experiment comes in.
Past food experiments on the International Space Station used seed bags (also called pillows) that receive water from syringes, which astronauts push into the bags. While this water is enough for lettuce to grow, tomatoes and similar crops use more water.
The new method lets astronauts cultivate romaine lettuce seeds in 12 passive orbital nutrient delivery systems (PONDS). PONDS units are less expensive than the seed bags and can hold more water, while providing more room for roots to grow.
(Image credit: David Saint-Jacques/NASA)