How space lettuce takes us one step closer to a space burger

If you met an astronaut, you probably wouldn’t ask them about their diet on the International Space Station (ISS). After all, these are people who have the words “space travel” on their CVs way more than you or I (unless you’re seriously prone to embellishment), so there are more pressing things to ask. And yet a small, but significant, step was made in the world of space cuisine when NASA announced that the first space salad is being grown and dished up on board the ISS.

Space salad isn’t quite as science-fiction as it sounds. In fact, it’s pretty mundane: red romaine lettuce, the kind of thing you quickly skim past when reading a restaurant menu. But it’s a huge deal, if not quite a giant leap, for the astronauts.

Assuming none of them drop dead – and they shouldn’t, given that previous space-grown lettuce has been tested on Earth – this will mark the point at which astronauts can become self-sufficient, without needing to rely on expensive food deliveries from Earth. If you think an Ocado delivery is pricy, it’s worth knowing that it costs $10,000 to send a pound of food to the ISS, according to NASA’s Howard Levine.

On top of that, it should also improve the astronauts’ quality of life. As NASA’s Dr Ray Wheeler points out: “Fresh foods, such as tomatoes, blueberries and red lettuce are a good source of antioxidants. Having fresh foods like these available in space could have a positive impact on people’s moods and also provide some protection against radiation in space.”

So how do you grow lettuces in space? Using a system called “Veggie”, pre-made seed “pillows” are exposed to blue and red LEDs to make them grow. After repeated watering, they’re ready to be harvested in about a month. Astronauts just have to wipe down the leaves with food sanitising wipes, and they’re good to go. Bon appetit!

If the idea of being excited by wiping down some weird-looking red lettuce makes you feel a bit sorry for the team on the ISS, spare a thought for earlier astronauts. They didn’t even have the ability to heat their food and, therefore, had meals composed of “bite-sized cubes, freeze-dried powders and semiliquids stuffed in aluminium tubes”.

The understandable grumbling about the standard of cuisine led to some improvements by the time the Gemini missions rolled around, but when you’re improving on “barely edible”, you shouldn’t expect Michelin-starred cuisine. The result – gelatin-coated cubes and plastic containers for freeze-dried foods – meant the menus now contained the likes of shrimp, chicken, vegetables, toast squares and apple juice.

It’s no wonder that the crew of Gemini III felt compelled to sneak a corned beef sandwich on board – an act that saw them disciplined and a congressional hearing called. A lot of fuss over a sandwich, you might think, but tiny crumbs can cause havoc with spacecraft machinery. It’s one of the many reasons that food in space has been so dispiriting to date.

Things have got steadily better over time, but growing edible plants in space is a big breakthrough for the astronauts on the ISS – even if they’re still a bun, some beef and a few potatoes away from a decent burger.