And here I was impressed with the yield of tomatoes I had from my backyard. These astronauts are munching on some space-grown lettuce.

NASA astronaut Shane Kimbrough managed to grow and harvest some Red Romaine lettuce entirely in space. The crew managed it with what's called a "cut-and-come-again" technique. Essentially they harvested parts of fresh lettuce, leaving remainders and the core of the plant together so that it grows and yields even more crop.

The goal for the crew is to have a harvest every 10 days while in orbit. Most of the lettuce will be used as food, while some will go towards scientific study.

The whole point of growing plants in space now is to study how microgravity affects the development of crops. One day, we could need to sustain life in space for long stretches of time by growing food. This crop of lettuce is another early step along that journey.

Now I'm hungry for lettuce puns.