Whether or not that old packet of seeds will germinate is a question that often arises in gardening. But when the seeds in question have taken a trip to the International Space Station (ISS), the answer gets a bit more complicated. In 2015, a million rocket (AKA arugula) seeds blasted off to spend six months in space. When they returned to Earth in 2016 they faced an even larger challenge – they were to be sown by a horde of little fingers as the RHS Rocket Science experiment turned school children into space gardeners!
Announced at the RHS Chelsea Flower Show in 2015, Rocket Science was part of Tim Peake’s Principia mission to the ISS. For 35 days children nurtured and monitored two sets of rocket seedlings. One had been to space, and the other had stayed on Earth. Would they be able to tell the difference? The RHS collected and analysed the results, and published their Rocket Science: Our Voyage of Discovery report in November 2016. Their key finding was that there was a small difference, with the space seeds being slightly slower to germinate.
Scientists at Royal Holloway took over and carried out experiments in controlled conditions to find out why there might be a difference in germination time. They confirmed that the space seeds are slower to germinate because they had been aged (damaged) by their trip into space. Once the dry seeds are watered they can repair the damage, but doing so leads to a slight delay in germination. Once the seeds have germinated, they can grow as normal.
If you want to know more you can read the press release from Royal Holloway, or tackle the paper that has been published in the scientific journal Life: Rocket Science: The Effect of Spaceflight on Germination Physiology, Ageing, and Transcriptome of Eruca sativa Seeds.
This morning, Jeremy Curtis from the UK Space Agency hosted a special webchat with Tim Peake, Alana Cama from the RHS and Dr Jake Chandler from Royal Holloway to talk about the Rocket Science project and what we learned from it.
One of the highlights for me is that Tim Peake talks about eating some of the zinnia petals that Scott Kelly grew in Veggie during his mission. Tim says that they’re quite bitter, but would be ok in a mixed salad! Later on, we also see that Tim brought home a dried pressed zinnia flower as a souvenir of his time on the ISS.
Tim also talks about looking after pea seedlings, and that was part of a Japan Aerospace Exploration Agency (JAXA) experiment called Auxin Transport Run #3-2. It was investigating the role of auxins (plant hormones) in pea and maize seedlings grown in microgravity.
Alana talks about why rocket seeds were chosen for this experiment:
- There was a 2kg weight limit, and the small size of rocket seeds meant more could be packed in and more kids would have a chance to be space gardeners.
- The name, of course, is perfect!
- Rocket is quick-growing, which meant the kids would see results quickly.
- Astronauts report a loss of taste and smell in space, and a preference for stronger flavours, so peppery rocket leaves are a perfect choice for a space crop.
If you watch the video you’ll also find out some fascinating stuff about where on the ISS the seeds were stored (and how they got lost for a while…) as well as how hard it was to get the seeds into space in the first place. And Tim explains why we will have to grow food in space, and how that research can benefit life on Earth. It’s well worth 36 minutes of your Lockdown Life!