Astronauts aboard the International Space Station (ISS) have, for the first time, eaten vegetables grown in space.
The crew ate red romaine lettuce as part of a Nasa study which is deemed critical to the success of the organisation's Journey to Mars programme.
The small-scale farming project, Veg-01, nicknamed #NasaVeggie on social media, is important for self-sufficiency, and the first few bites were taken by three of the ISS crew at around 5pm GMT.
Nasa's Scott Kelly called the small-scale farming project "one small bite for man, one giant leap for #NASAVEGGIE and Journey to Mars," on Twitter.
Adding oil and vinegar, the crew members sampled the fruits of their labour after growing the lettuce for 33 days on the ISS.
The Veggie system was developed by Orbital Technologies Corp (ORBITEC) in Madison, Wisconsin and uses red, blue and green LEDs for plant growth.
Dr Gioia Massa, a Nasa scientist who has worked on the Veg-01 project, said the development could have psychological benefits.
"The crew does get some fresh fruits or vegetables, such as carrots or apples, when a supply ship arrives at the space station. But the quantity is limited and must be consumed quickly.
"The farther and longer humans go away from Earth, the greater the need to be able to grow plants for food, atmosphere recycling and psychological benefits. I think that plant systems will become important components of any long-duration exploration scenario," Dr Massa said.