At 5 am a cold November morning, at Esrange Space Center, in the very north of Sweden, Professor Emeritus Lena Kautsky is nervously awaiting the latest news. The weather has been shaky the last days, and a change of wind or an unexpected fog could jeopardise everything. Will the rocket carrying sixteen small shoots of bladderwrack really be allowed to set off this morning?

For more than 30 years, she has been puzzled by a question: why does bladderwrack (Fucus vesiculosus) always reproduce at full or new moon in the Baltic Sea? Could it be that the algae feel the gravitational pull of the moon? The rocket launch she is waiting for could bring her one step closer to solving the mystery.

Bladderwrack reproduction involves the release of eggs and sperm from female and male plants into the water where fertilisation takes place. In the Atlantic, this synchronisation is understandable because it is linked to the tides; when the water is at its lowest, the bladderwrack is exposed to the air and dehydrates. When the tide turns, the seaweed is covered with water again and releases its eggs or sperm, and the fertilised egg can easily reach the bottom and settle.

Bladderwrack with shoots. Photo: Lena Kautsky

But in the Baltic Sea, there are no tides. Here, the bladderwrack is always submerged, but it still reproduces according to the lunar cycle.

Having done all the experiments she could think of, Lena Kautsky mentioned in a radio broadcast that the only thing left to do was to send bladderwrack into space. This would allow her to see how the algae reacted on weightlessness –microgravity – and if it would it affect reproduction.

It was Gunnar Florin from the Swedish Space Corporation who heard the radio broadcast and contacted Lena, offering her a place on a sounding rocket that was to be launched from Esrange with several scientific experiments on board.

"This was a fantastic opportunity to test the idea of the effect of the moon's gravitational pull. Of course it was a big yes!" says Lena Kautsky.

Careful preparations

The time since then has been filled with extensive preparations. Lena Kautsky and her colleague Ellen Schagerström have had help in constructing a small box containing several small tubes and designed to fit in the rocket. During the summer and autumn, they collected small shoots of bladderwrack around Askö Laboratory, south of Stockholm, which were then grown in the laboratory at the Department of Ecology, Environment and Plant Science under controlled light and temperature conditions. 

Lena Kautsky at Esrange Space Center. Photo: Olle Jansson

As the launch approached, the shoots were placed in tubes containing 1.5 ml of brackish water, and brought to Esrange in Kiruna. Once there they were placed in the rocket for many days and the waiting began.

"The weather conditions have to be perfect for the launch – there can’t be too much wind, snow or fog," she explains. "We had daily meetings to go over the latest forecast. It was both exciting and nerve-wracking, as we were not sure about how long time the shoots would survive in the limited amount of water.”

Finally, the big day arrived. On Monday 25 November, the researchers were told that there was a chance of a launch between 5am and 6am the following morning. The countdown was scheduled for 5:20, but a sudden snowfall put preparations on hold again.

“Everything was uncertain until the very end. But then the snow stopped falling. Countdown began at 5:40 and 6:00 the rocket was launched. It was breathtaking, fantastic," says Lena Kautsky.

The rocket was launched at 6 am on 26 November. Photo: Olle Jansson

The spaceflight lasted ten minutes, six of which were spent in microgravity.

"Then we had to wait again for the helicopter to bring the payload with all the experiments to the main hall," says Lena Kautsky. "We all stood and waited until the tractor with the payload arrived at 10:45. But something was wrong, the lower part where our experiment was placed, was not there!

The cargo from the rocket returns. Photo: Lena Kautsky

Fifteen minutes later, an employee entered the hall with some broken metal parts.

"Among them was our box with 16 tubes of bladderwrack, whole and undamaged. Just a bit icy and snowy. It had survived! It was found in the water on the lake shore".

After rushing to the lab, Lena Kautsky was able to conclude that the tubes had not frozen and that the samples had survived.

"Such a relief!"

The box containing the bladderwrack samples shown to be intact. Photo: Lena Kautsky

Analyses and next steps

In collaboration with colleagues from the University of Helsinki, a series of genetic analyses will now be carried out on the samples. The aim is to find out how the bladderwrack has reacted to the stress and whether proteins or cell structures have changed.

Hopefully, this first space flight will be followed by others. If the analyses show that the bladderwrack can cope with being launced into space , Lena Kautsky and Ellen Schagerström plan to apply to send bladderwrack to the International Space Station (ISS).

Researcher Ellen Schagerström.

"To be able to test the bladderwrack as a space-going organism on this mission was a tremendous opportunity for us and has given us a lot of experience and insights on how experiments in space must be designed", says Ellen Schagerström. "The team at SSC were really helpful and fun to work with. This will be extremely valuable for our upcoming application for an ISS-based experiment."

"If we could send fertile bladderwrack to the ISS for two weeks during a full moon, we could see if they can reproduce without gravity. This would bring us closer to solving the mystery that has puzzled me for so long," says Lena Kautsky. "If there is a US-based scientist out there who would like to collaborate on this – please get in touch!"

Text: Lisa Bergqvist