A bright orange zinnia flower has blossomed aboard the International Space Station (ISS), marking a first in space.
Zinnias grow easily on Earth and blossom in abundance in summer. But on the ISS, where they were taken to carry out experiments, the plant has had trouble adapting to microgravity.
This experiment began on Nov 16 last year, with the aim of producing food for long manned space missions through autonomous gardening, which is key to survival. Several zinnia plants were doing poorly last month as mould grew on some of their leaves because of high humidity, according to Nasa.
Growing edible flowers such as zinnias is part of a long-term Nasa project known as Veggie.
The challenging process of growing the zinnias in microgravity has provided an exceptional opportunity for scientists back on Earth to better understand how plants can grow under such a condition.
The ISS crew had already grown and eaten lettuce last year aboard the orbiting craft and hope to produce tomatoes by next year.
Growing vegetables on the space station began in mid-2014. They are grown aeroponically - without soil, in an air or mist environment. The system requires much less water and fertiliser, and plants grow three times faster than on Earth, said Nasa.