Unlike what you'll get in Chipotle, this lettuce is free of disease-causing microbes and safe to eat.
We're not worried about growing food in space any time soon when we can't even launch a telescope without a generation of delays and $10 billion in cost overruns but this is good proof-of-concept. Astronauts eat just fine but the press release makes their food sound terrible, noting their food has "often been sterilized by heating, freeze drying, or irradiation to make them last."
Scientists know this ISS lettuce got more irradiation than the food astronauts eat and it is still just fine. Thanks to a long-debunked 1940s claim - the Linear no-threshold (LNT) model - about radiation, it is no longer officially recognized that the dose makes the poison in radiation like anything else. The Washington Post continues to insist LNT is correct but they are reflexively anti-Republican and Republicans have said it deserves a rethink in light of modern science, which is why WaPo trotted out a history major rather than a scientist for their LNT article. Meanwhile, the same Washington Post endorses organic foods which have been created by, you guessed it, radiation, in the form of mutagenesis. Literally, chemical and radiation baths.
Radiation hysteria is so pervasive California elites are worried about 5G cell phones, and that isn't even ionizing radiation. It's less radiation than a light bulb. But people see the word radiation and the precautionary principle paralyzes them. One of the authors even works at Kennedy Space Center and still claimed that the radiation to kill microbes in food is somehow worse than the high-energy cosmic rays that the lettuce got in space. Likewise, they suggest heat is bad - sorry pasteurization, let's forget you saved a billion lives.
It's a mistake. People flock to Guarapari Beach in South America for its "healing" properties and its background radiation levels are 300X higher than what the American government considers safe. My maternal grandfather was on garrison duty in Nagasaki right after the atomic bombs knocked Japan out of World War II and didn't die until 52 years later.
Forgetting the press release hype, the control was plants grown on Earth using Kennedy Space Center's laboratories with the same temperature, carbon dioxide, and humidity readings from the ISS, and replicated in the Kennedy Space Center's laboratories with a 24-48 hour delay. On the ISS, the lettuce grew from 33 to 56 days and crew members ate some and froze the rest for transport back to terra firma.
On the left, the red romaine lettuce in Veggie pillows aboard the ISS with the light panel off, while on the right the red light panel is on. Bellows are up.
Similar microbes to earth lettuce - except for the bad kind
The results were too variable to be solid when it comes to benefits (some had more potassium, some had more phenolics) but they weren't worse.
What was interesting was the similarity in microbes. It would be expected that space would lead to distinct microbiology but DNA sequencing showed instead that microbial genera on the leaves and in the roots were similar for the space-grown and laboratory lettuce. None of the detected bacteria genera cause disease in humans.
If the next President doesn't do what the last one did and just cancel his predecessor's space program so he could replace it with one having his own brand, we might actually see Artemis-III go back to the moon this decade or Mars in my lifetime, but the crew is not going to be worried about eating space-grown lettuce when that happens, Still, this was an interesting experiment and I am hopeful NASA gets back to being a space exploration group and not a terrestrial job works program for federal union employees.
Let's hope that during the delays we can grow more crops in space. While government bureaucracy moves at snail's space, there is no reason for science to wait.