Astronauts may now be able to satisfy their sweet tooth as researchers have found a strawberry that can grow in space with little maintenance and energy.

Cary Mitchell, professor of horticulture, and Gioia Massa, a horticulture research scientist at Purdue University in the US, tested several cultivars of strawberries and found one variety named Seascape, which seems to meet the requirements for becoming a space crop.

"What we're trying to do is grow our plants and minimise all of our inputs," Massa said. "We can grow these strawberries under shorter photoperiods than we thought and still get pretty much the same amount of yield."

Seascape strawberries are day-neutral, meaning they aren't sensitive to the length of available daylight to flower.

Seascape was tested with as much as 20 hours of daylight and as little as 10 hours. While there were fewer strawberries with less light, each berry was larger and the volume of the yields was statistically the same.

"I was astounded that even with a day-neutral cultivar we were able to get basically the same amount of fruit with half the light," Mitchell said.

The findings showed that the Seascape strawberry cultivar is a good candidate for a space crop because it meets several guidelines set by NASA. Strawberry plants are relatively small, meeting mass and volume restrictions.

Since Seascape provides fewer, but larger, berries under short days, there is less labour required of crew members who would have to pollinate and harvest the plants by hand.

Needing less light cuts down energy requirements not only for lamps, but also for systems that would have to remove heat created by those lights.

"We're trying to think of the whole system -- growing food, preparing it and getting rid of the waste," Massa said. "Strawberries are easy to prepare and there's little waste."

Seascape also had less cycling, meaning it steadily supplied fruit throughout the test period. Massa said the plants kept producing fruit for about six months after starting to flower.

Mitchell said the earliest space crops will likely be part of a "salad machine," a small growth unit that will provide fresh produce that can supplement traditional space meals.

Crops being considered include lettuce, radishes and tomatoes. Strawberries may be the only sweet fruit being considered, he said.

These findings were reported online in Advances in Space Research.