I was scrolling through Twitter recently when I spotted something in a picture of the Veggie growth chamber on the ISS that I hadn’t noticed before – there’s a triangular plaque at the back.

Two photos tweeted by astronaut Jessica Meir of the Veggie growth chamber, showing the memorial plaque.
[Image credit: NASA]

I wanted to know more, so I did a quick search and came across a NASA update from December 2016. It was mainly about the Veg-03 experiment, which was the first to trial the ‘cut-and-come-again’ harvest technique on the Outredgeous space lettuce.

The update also includes an explanation of the plaque, which it says was mounted that summer in memory of two pioneering space biologists. The plaque reads:

“Dedicated to the memory of space biology pioneers Thora Halstead and Ken Souza, for all they did to plant and nurture the seeds of biological research in space.” 

Those flowers look like space zinnias to me 🙂

According to NASA Watch, Thora Halstead “practically invented space biology”. During her career she focused on the study of how the cells of living organisms (often plants) respond to a low-gravity environment, publishing more than 40 research articles.

NASA tells us that Ken Souza conducted one of the earliest life science spaceflight experiments on Gemini 11. “In 1992, his frog egg experiment on SpaceLab-J provided the first evidence that a vertebrate species can reproduce in the absence of gravity.”

“Both Halstead’s and Souza’s early stewardship of a new science that became the discipline of space biology will continue to benefit future explorers on the journey to Mars.”

Astronaut Kate Rubins installed the plaque on the ISS on 9 September 2016, recording a lovely tribute video. 

According to SpaceRef, copies of the plaque were flown in space and then returned to Earth and presented to the families of Ken Souza and Thora Halstead.

Having also spotted identical plaques on the Veggie growth chamber in the Space Station Processing Facility at NASA’s Kennedy Space Center in Florida, I do wonder whether those have been flown in space too?

It’s a lovely story, a fitting tribute to two pioneering scientists, and an insight into the way that the ISS collects meaningful nicknacks and keepsakes, in the same way that our homes do on Earth. Although you may associate archaeology with exploring our ancient history, there’s an ISS Archaeology project that is using material culture​ to study the ISS as a “microsociety in a miniworld”. The ISS has been continuously inhabited for 20 years now!