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The ‘cosmic’ zinnias have blossomed

The first flowers grown in space blossomed on 16 January. The efforts made by astronaut Scott Kelly, who batted against mould and leaf rust, have been rewarded


A happy event on the Space Station: the yellowy-orange petals of the zinnias finally appeared before the eyes of caring astro-gardener Scott Kelly, who has worked hard to achieve this result over the past two months, first in a team with Kijell Lindgren and then with the aid of new entry Tim Peake.  

The pleasant surprise arrived during the night of Saturday 16 January, after a period of suspense due to the presence of mould and leaf rust that made everyone fear for the experiment.  

When Kelly, a NASA astronaut on a ‘one-year mission’, saw the explosion of colour of the zinnias in the Veggie greenhouse he just had to communicate his joy through his Twitter and Facebook profiles. 

Kelly posted the photos of the first flowers to bloom in conditions of microgravity, arousing the enthusiasm of the ‘social network followers’ who saw the simple beauty of the zinnia as a symbol of hope and progress for humanity. 

“The blooming of the zinnias on the ISS makes it possible for us to observe this physiological process in space for the first time: an important scientific objective has undoubtedly been reached, but it also has a completely different significance - commented Sara Piccirillo from the Human Flight Unit of the Italian Space Agency - In fact, it marks a huge step forward in the possibility of recreating in orbit an environment similar to that on Earth, in which the plants contribute to the well-being of the crew, also on a psychological level.”

La serra Veggie (Credits: NASA)

In recent weeks the condition of the plants had left Kelly and the Veggie scientific team waiting with bated breath. The astronaut had, in fact, photographed a couple of zinnias in a bad condition, with mould and leaf rust caused by a stress situation. 

In particular, it was found that water was dripping out of the cultivation bed and had covered the little plants. Furthermore, the leaves were showing signs of exudation and this had made it necessary to reduce the airflow inside the greenhouse. 

“Flowering is a complex event that marks the passage from the plant's vegetative stage to its reproductive stage”, explains Sara Piccirillo. “This transition involves deep changes in plant morphology, culminating in the appearance of the flower’s highly specialized structures.”  

Despite Kelly's loving care, two of the little plants died. At first glance, this might seem to be a failure in Veggie's cultivation system, but in reality it was turned into a useful opportunity for researchers and astronauts. 

In fact, the remains of the little plants were uprooted from the cultivation bed and frozen, waiting to be returned to Earth. The diseased leaves will be analysed in order to get a better understanding of the growth process in microgravity and of which critical problems may occur in the parameters fundamental for the growth of a plant, such as irrigation and light. The study of these critical problems will also be very useful to the astronauts, helping them to improve their skills as ‘space farmers’ and to act more autonomously.  

The Veggie greenhouse, created by the American Company Orbital Technologies, consists of a sealed growing chamber, lit by special LED lights, equipped with an irrigation system and folding walls that make it possible to increase its volume as the little plants grow. The soil is a clay-based, inert substrate.