(CBS SF) — Green-thumbed astronauts tasted the fruit of their labors after harvesting space-grown vegetables for the first time ever.

In what may be the most historic salad in the history of mankind, International Space Station crew members on Monday sampled some of the red romaine lettuce from the orbiting greenhouse — paired with oil and vinegar, of course.

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The astronauts will eat half of the harvest and then package and freeze the rest on the station until it can be returned to Earth for scientific analysis.

NASA has been studying how vegetables grow in space and their nutritional value since May 2014.

International Space Station Greenhouse (NASA)

International Space Station Greenhouse (NASA)

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NASA has been using LED lights to grow plants since the late 1990s, , according to Dr. Ray Wheeler, lead for Advanced Life Support activities in the Exploration Research and Technology Programs Office at Kennedy.

“There is evidence that supports fresh foods, such as tomatoes, blueberries and red lettuce are a good source of antioxidants. Having fresh food like these available in space could have a positive impact on people’s moods and also could provide some protection against radiation in space,” Wheeler said.

Growing vegetables would support future deep space missions by providing crew members with a way to grow some of their own fresh food.

NASA plans to grow food on future spacecraft and on other planets as a food supplement for astronauts. (NASA)

NASA plans to grow food on future spacecraft and on other planets as a food supplement for astronauts. (NASA)

But it’s more than just astronauts getting their essential vitamins and nutrients. Having a little piece of Earth to take care of when living in an extreme and stressful environment has a positive impact.

“The farther and longer humans go away from Earth, the greater the need to be able to grow plants for food, atmosphere recycling and psychological benefits. I think that plant systems will become important components of any long-duration exploration scenario,” says Gioia Massa, a NASA scientist with the vegetable growing project.

Nicole Jones is a digital producer for CBS San Francisco. Follow her musings @nicjonestweets

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