Astronauts have been enjoying a fresh supply vegetables to keep them healthy in space. Two NASA scientists explain how the crop-growing experiments worked.

• Astronauts in space recently enjoyed a fresh supply of vegetables, including pak choi plants.
• Crews turned them into a delicacy by marinating the leaves in garlic paste and soy sauce.
• NASA scientists told Insider how the crop-production experiments worked.

• See more stories on Insider’s business page.

Of the many challenges astronauts will face in future missions to the Moon and Mars, keeping healthy is one of the most crucial.

But, in recent days, astronauts aboard the International Space Station (ISS) found startling solutions to sustain them on long-lasting missions. They recently enjoyed a fresh supply of vegetables due in large part to the efforts of NASA’s SpaceX Crew-1 mission commander and Expedition 64 crew member, Michael Hopkins.

Insider spoke to two NASA scientists, Matt Romeyn and Gioia Massa, who work on the crop-production experiments, known as Veg-03Kand VEG-03L. Romeyn is the lead scientist on the experiments and Gioia is a Kennedy Space Centre plant scientist.

Veg-03Kand VEG-03L intended to test a new space crop, “Amara” mustard, also known as Ethiopian kale, and a previously grown crop, “extra dwarf” pak choi. Both yielded successful results. Since their harvest by Hopkins on April 13, the two crops grew for 64 days, the longest duration leafy greens have grown on the space station.

According to Romeyn, the pak choi germinated for so long that the plant began to flower as part of its reproductive growth cycle. This was thanks to Hopkins’ effort in using a small paintbrush to pollinate plant flowers.

They took the approach after Hopkins’ and Romeyn discussed multiple options for the pollination process, including allowing the flowers to self-pollinate themselves.

“We were very happy with his efforts to pollinate those flowers to look at the possibility of producing seeds from them,” said Massa.

She added that this approach “will also be very critical in the future to be able to produce new plants without getting seeds from Earth, so very important for long-duration missions such as a mission to Mars,” and the Moon.

Hopkins’ was hugely interested in crop production, said Romeyn and Massa, and he devoted much of his free time in space to caring for them. This meant monitoring and watering the plants every day, as well as determining the optimal time to harvest them.

“It’s a really challenging thing and so he had to check those plants pretty much every day and monitor their growth and adjust his approaches to growing them,” Massa said.

New methods of harvesting were also among Hopkins’ discoveries in space-crop production. This included a sustainable approach to harvesting, called “cut-and-come-again harvesting”, which entailed harvesting multiple times from the same plant Massa explained.

“He’s been just an incredible gardener and scientist for us,” she added.

Massa said the crew have been eating the pak choi as a side dish, by marinating the leaves in garlic paste and soy sauce, and then heating them up in a small food warmer.

“Delicious, plus the texture or crunch,” Hopkins wrote in experiment notes after tasting the “Amara” mustard plant grown in space.

According to Massa, the crew have also put the leafy greens on tacos or cheeseburgers that they’ve made. In the past, Massa saw crew members enjoy the “Amara” mustard plant as lettuce wraps. “I know the Russians had canned lobster salad and so they made lettuce wraps with the canned lobster salad,” she added.

For now, the astronauts are focusing on the “pick-and-eat salad” crops, which don’t require cooking or processing, because there’s not that much capability to do that type of work on the space station.

Next year, there are plans to grow ‘dwarf tomatoes,’ which Massa likened to cherry tomatoes.

Romeyn explained that NASA scientists on the crop-production project look to grow crops high in Vitamin C and Vitamin K for astronauts in space. This is because research at Johnson Space Centre found the nutritional value of food stored in space ultimately deteriorates.

“The vitamins and the quality can break down for some of the food items,” Massa said.

This is why a lot of the work being done in space agriculture, from a nutritional and supplemental perspective, is to feed crews travelling to and from Mars, Romeyn explained. “We may not have full nutrition without supplementing with the fresh crops,” he said, in regards to a future Mars mission.

NASA officials are certainly hopeful that a future crewed mission to Mars is on the cards. When the agency announced its partnership with SpaceX to return to the moon by 2024, it said in a press release that a trip to the moon would be an important step toward an eventual mission to the Red Planet.

“It’s something I hoped I would see,” said Scott Hubbard, a SpaceX advisor who formerly led NASA’s Mars program, previously told Insider in an interview.