Physicist and honorary South Australian Dr Shannon Walker explains what it’s like living on board the International Space Station

Is there life on Mars? Maybe. There’s definitely life on the International Space Station. Lainie Anderson asked physicist Dr Shannon Walker what it’s like up there.

Dr Walker tends to plants growing inside the veggie plant growth facility for the Veg-03J space botany study. The investigation is cultivating Extra Dwarf Pak Choi, Amara Mustard and Red Romaine Lettuce which are harvested on-orbit with samples returned to Earth for testing. Picture NASA

On a sweltering January night in 2019, Shannon Walker sat in a deckchair under a star-filled sky on Mutooroo Station in the South Australian outback.

Sipping red wine, she chatted with starry-eyed station workers about how the International Space Station, orbiting just 408km above the earth, was actually closer to Mutooroo than Adelaide – and how she hoped to get back up there one day.

Dr Walker is no stranger to space or South Australia.

Married to Adelaide’s own former astronaut Dr Andy Thomas, the physicist considers herself an “adopted South Aussie” and has won over many of us with her ready laugh, razor-sharp intelligence and genuine curiosity on regular visits to SA since the couple’s Texas wedding in 2005.

With aspirations to become an astronaut since high school, Dr Walker was accepted into the NASA program in 2004 before beingtrained by the Russians (which, she says, technically made her a “cosmonaut”) and spent 161 days aboard the International Space Station in 2010.

She’s back up there again now, this time serving as a flight engineer on the ISS after launching with NASA’s SpaceX Crew-1mission in November – becoming the first woman on the first crewed mission of Elon Musk’s privately-built spacecraft program.

And she’s taken reminders of SA with her: a boomerang handcrafted by Kaurna man Jack Buckskin “to inspire people young andold to remember that human exploration has a long and deep history within the earliest human culture”; and an Adelaide Crows jumper that reflects Dr Walker’s healthy sense of humour (and that the mighty Crows fly as one, even in space).

Here, our adopted astronaut talks to the Sunday Mail about life in orbit, 408km up.

Dr Walker on board the ISS with a boomerang made by Kaurna man Jack Buckskin.

Can you step us through your average day on the International Space Station?

Each day is different on the ISS. One day could be filled with science experiments and the next day I might be performing maintenance on the station, either preventative to keep things running properly or because something has broken.

But, in general, I start my day at six in the morning. The station operates on Greenwich Mean Time, so that means when I get up, it is the middle of the night in Houston and Huntsville, Alabama, the early morning for Cologne, Germany, a bit later for Moscow, Russia, and the afternoon for Tsukuba, Japan.

Those cities are where there are control centres for each of the ISS partners. NASA has two because Houston runs the station and Huntsville runs our research program.

The first thing I do in the morning is check my schedule for the day. Overnight, the ground teams finalise what it is that we are to do that day and I take a look to see what is in store for me and how the day is organized.

Usually, we have some activities that can be done at any time and some that have to be done on the timeline as scheduled.

The difference between the two is how much involvement the ground needs to have. They might need to send some commands to a piece of hardware during the activity. Or, it could be that the scientific team that has an experiment on board will be tied into the communications loops as we are doing their research. So, we have to do such activities in concert with the ground and as scheduled.

We Fly as One. Dr Walker’s Crows jumper, on board with her on the ISS. Picture: NASA

After looking at my schedule and reading any information that the ground has sent us about the day, I get dressed and have breakfast. At around 7.30am (give or take, depending on the satellite links) we check in with each of the control centres around the world to see if they have any additional information for us. Following that, the work day starts.

Every day, I have exercise time scheduled on two different devices. We have a treadmill (you wear a harness that keeps you from floating away), a bike (no seat as your feet are clipped to the pedals), and a machine that provides resistance and functions as a way to do the equivalent of lifting weights.

We do weightlifting/resistive exercise every day because that is the main way we keep our bones and muscles strong.

We use the other exercise devices for our cardiovascular health and generally alternate between the two.

The total time for exercise and clean up comes out to about 2½ hours a day.

We are allotted a one-hour break in the day for a midday meal. The rest of the day is taken up with whatever the ground needs us to do.

At the end of the day, around 7.30pm, we have another check-in with all the control centres.

Our work day spans about 12 hours, with 11 of those spent on
either exercise or ground dictated work.

After the final check in, we have dinner. After dinner is when I typically make phone calls to friends and family as it is a reasonable time of day for folks in the States. Our scheduled sleep time starts at 9.30pm.

Normally, we have a Monday through Friday work schedule. Saturday is slated for housekeeping and exercise.

The station is a big place and it takes several hours to vacuum and clean its surfaces. Thankfully, we have a large crew so we can divide up the tasks.

Dr Walker sets up hardware inside the Microgravity Science Glovebox for the Solidification Using a Baffle in Sealed Ampoules (SUBSA) experiment. SUBSA crystallizes melts in microgravity to learn more about the process of semiconductor crystal growth to benefit Earth and space industries. Picture NASA

We also take care of things that are usually not on the formal schedule but are hugely important, such as keeping the cargo organised or getting out the next round of food rations.

I know it sounds simple but activities in space always take a lot longer than doing the equivalent activity on the ground.

And, if you are not extremely diligent in organisation, you will have a huge efficiency hit when you are trying to accomplish the “real” work.

Sundays are typically off-duty days (except for exercise, of course).

Dr Walker looks out of the international space station's cupola at the Caribbean view beneath during her first stint on board the ISS in November, 2010. Picture NASA

There are many times, however, when the weeks will not be laid out in a typical fashion.

For example, if we have a cargo ship that has arrived and brought up science that needs to be done before that cargo ship returns to the ground, then our scheduled will be dictated by the science.

That usually means that the weekends are scheduled like normal work days.

Any free time we might have is usually spent keeping up with friends and family via email or phone calls, reading, and, of course, looking out the window at our beautiful planet.

Do you feel differently about the earth, looking down on it from up there? (I know it made Andy Thomas feel very strongly about the need for humans to better protect it.)

What strikes me when I look at the planet is how amazingly fragile it appears. At dawn and dusk you can get a good sense of how thin our atmosphere is.

During the daytime you can see the run-off from rivers into the oceans. You can see lakes that are drying up or have unusual algae blooms. You can see the smoke from wild fires or ones that have been set to clear land. You can see that smoke travel from one continent across an ocean to the next continent.

It is very obvious how interconnected everything is on the planet.

Walker with husband Andy Thomas get suited up as part of their astronaut training at NASA in Houston, Texas, 2004. Picture by Jeff Rayner

At the same time, you can also see incredible beauty.

The range of colors is stunning – the variety of blues in the oceans, the reds of Australia or northern Africa, the greens of the vegetation, the whites of the snow-capped mountain ranges, not to mention the colours in the sunsets. Lightning displays at night are also quite fascinating and beautiful, as are aurora. All of this taken together gives me a very strong sense of urgency about taking care of and protecting our home.

What’s the weirdest thing to get used to?

That is an interesting question. I think what’s weird is how quickly it becomes normal to be floating all the time. Your body and mind adjust very quickly and it just seems normal to work on the ceiling or float down to the other end of the station.

What do you do in your down time – if you get any?

Any free time I might have is usually spent keeping up with friends and family via email or phone calls, reading, and, of course, looking out the window at our beautiful planet.