Astronauts Kjell Lindgren (L) and Scott Kelly sample lettuce harvested for the first time aboard the International Space Station in this handout photo provided by NASA during Expedition 44, August 10, 2015. [Photo/Agencies]

LOS ANGELES - The six astronauts currently living on the International Space Station (ISS) have become the first to eat food grown in space, the US space agency NASA said Monday.

In a video released by NASA, the three astronauts Scott Kelly, Kjell Lindgren and Kimiya Yui are seen eating the fruit of their labor.

"It tastes good," US astronaut Kelly said, following a brief three-way toast with lettuce leaves in hand. "It kind of tastes like arugula."

The fresh red romaine lettuce accompanying the crew's usual freeze-dried fare is far from the first crop grown on the space station.

For decades, scientists have experimented with plants in space which have typically been sent to Earth for examination rather than eaten.

This step is significant in that NASA's eventual manned journey to Mars may rely heavily on a crew's ability to sustain themselves on food sown and harvested exclusively in the microgravity of space.

A number of technologies have been explored for these space-farming experiments. Orbital Technologies (ORBITEC), for example, partnered with Kennedy Space Center to develop the plant growth system, known as Veggie, that produced this most recent crop of lettuce.

Plants will be an integral part of any life-support system for extended missions, providing food and oxygen and processing waste, NASA said.

Further significant advances will be necessary, and each of them promises to bring new innovations to agriculture here on Earth.