Life in space is very different from life on Earth.

The daily activities needed to keep the spaceship functioning and astronauts healthy – even simple things like dental hygiene – need specialized training in order for astronauts to stay safe.

When Dave Williams, a Canadian astronaut and physician, was told he would head to space in 1998, he underwent rigorous preparations.

Williams, like every astronaut, completed the usual basic training, which, in addition to the more technical aspects, also involved how to do daily activities in space, including something called "toilet training."

Also part of that training are conservation measures, some of which can be applied on Earth as well.

Items like food and water are treated with utmost importance due to a lack of running water or fresh fruits and vegetables, and it's a shift in mindset astronauts need to make before going into space.

When in space, people learn to appreciate many things taken for granted on Earth, like a hot shower or a juicy orange.

"We develop what's called the planetary perspective, a broader appreciation for how important it is to take care of our planet," Williams told CTVNews.ca in an interview.

During his second spacewalk in 2007, Williams said, an important quote came to his mind while looking at the Earth from the International Space Station (ISS).

"What struck me at that time was Marshall McLuhan's quote from the 1960s: 'We live in a global village,'" he said. "And when you orbit the Earth every 90 minutes, you realize we do, in fact, live in a global village. What happens in one part of the world affects all of us…And we need to take care of that village."

Not only do astronauts need to train for their specific missions, but they also need to learn new habits on how to function in space, ideas that Williams thinks can teach earthlings how to reduce their impact on the planet.

"Whether it's using solar panels to provide electric power or how we manage our water supply in space, there are a lot of transferable technologies and lessons that we can implement today that will help protect the planet for the future," he said.

REDUCING WATER USE

In space, as on Earth, there's a need to conserve water.

Canada holds 7 per cent of the world's renewable freshwater and for most communities, taking a hot shower, flushing the toilet or grabbing a drink is as simple as turning on the tap.

But across many parts of the world, where water must be rationed, or in many Indigenous communities in Canada that have spent decades under boil-water advisories, it isn't that simple.

Additionally, as climate change speeds up the water cycle and pollutants seep into waterways, the life source is a sought-after commodity.

In space, astronauts bring water with them on missions to the ISS, but it takes up a lot of room. To ensure every drop counts, there are a number of practices astronauts abide by.

While the techniques used in space may not all be solutions to the problems on Earth, the ideas behind them may help with conservation measures.

"As an astronaut, the vast majority of the water that I use in space is simply to drink and stay hydrated," Williams said. "Whereas on Earth, the vast majority of the water that I use is not actually for drinking, it's for other stuff."

Brushing teeth, showering and toilets look completely different in space to make sure water is not wasted. Instead of drains or taps, astronauts use water-filled bags for washing.

Because of a lack of gravity, water appears in droplets on the skin, which astronauts use to spread around — essentially a sponge bath — before drying off.

Rinseless shampoo and edible toothpaste help keep their bodies clean while working in space and conserving their limited water supply.

Each day astronauts will have used as little as four litres of water, 90 per cent of which is for drinking, Williams and co-author Linda Pruessen wrote in a new book, titled, "Space on Earth: How thinking like an astronaut can help save the planet."

Humans' bodily functions still happen in space, meaning astronauts need to do "toilet training," which includes learning how to use a waterless toilet.

"Actually, we recover the urine that goes into the space toilet, and put that through special filters and processors," Williams said. "(That's why) we joke and say that today's coffee will be tomorrow's coffee."

The technology is called the Environment Control and Life Support System, which can recover water not just from urine but from moisture in the air including sweat.

According to the book, the ISS recycles about 90 per cent of its water each year.

While most here on Earth are unlikely to adopt urine filtration procedures, Williams believes the mindset astronauts have could benefit the world, if everyone used less water it would stay cleaner and reduce water scarcity for some countries.

Williams says people can "emulate being an astronaut" by using less water in their daily activities in simple ways, like not letting the tap run while they brush their teeth.

And the technology used to recover water is already being used on Earth, like in Iqaluit, where a scientist installed a biofilter in his sewage tank to filter out harmful bacteria, so the water could then used for washing clothes and flushing toilets, the book reads.

Waterless toilets are not mainstream yet, the book reads, but the possibility of the technology could eventually be the norm like it is in space.

SUSTAINABLE FOOD SOURCES

What will likely not be mainstream on Earth is the food astronauts eat in space. Although packed with nutrients and able to fuel missions, the food astronauts consume is not a replacement for fresh fruits and vegetables.

"Most of the food we get on the space station is like camping food," Williams said. "It's sent that way because we can preserve it in a pantry. We don't really have foods that are stored in fridges in space."

Food comes in baggies that need to be rehydrated like some camping rations. A variety of food is provided to astronauts, including chicken, seafood and peanut butter, and drinks like orange juice and coffee.

But this will never replace freshly prepared food.

"When you're in space for a long period of time, you begin to develop these food cravings," Williams said. "It's because the menu is relatively restricted. You don't have the same breadth of food choices in space you would if you're just simply living in your local neighbourhood on Earth."

Instead of living off dried goods, scientists have started to change what crops and plants would look like in space. There are limited areas to grow foods and a lack of dirt, but researchers have developed ways to grow plants.

Hydroponics is a relatively new way of farming, using water and UV rays to produce food. Instead of roots in the dirt, plants are put in water, and in some cases they actually grow more food than with traditional farming practices, Williams said.

In 2014, scientists developed the Vegetable Production System, which is a small garden that holds six plants situated in a pot of clay-based fertilizer. Light-emitting diodes (LEDs) helped plants to grow and successfully yielded three types of lettuce, Chinese cabbage, mustard, red Russian kale and flowers.

"One of the NASA astronauts actually had a hamburger with some lettuce grown in space on it, which is really cool," Williams said.

Flowers, although not edible, do provide a sense of comfort to astronauts, which Williams says is "like having a little bit of Earth" with them.

If harnessed, innovations like hydroponics can provide fresh food to astronauts and be replicated on Earth.

Growing food takes up a lot of land mass, which alternatively could be kept natural if hydroponics is used.

In places like cities, where green space is hard to come by, hydroponics could be a method of urban farming, providing families with freshly grown food with a low emission impact.

"In northern Canada, where getting fresh fruits and vegetables is a real challenge, people are now converting shipping containers into hydroponic gardens," Williams said.

To think like an astronaut, Williams encourages people to grow their own hydroponic garden or visit a local farmers' market.

REDUCING WASTE

In space there is an unspoken rule around meal times: if an astronaut hydrates it, they eat it.

"We actually waste a lot of food on Earth. Sometimes we'll prepare too much food and we just throw it in the garbage, or sometimes people only eat part of what they have on their plates," Williams said. "In space, whatever you prepare, you eat the whole thing because we don't want the trash."

The challenge of finding a spot for garbage is part of the reason astronauts avoid unnecessary trash like food waste. When there is garbage, astronauts give the bags to the resupply ship from Earth to bring back down, but this is not sustainable.

"What will happen when the next moon mission is launched? Or a future mission to Mars? Storing trash on board a small interplanetary spacecraft won’t work," the book reads.

To tackle this issue, astronauts try to reduce the amount of waste they generate, especially with food.

"With your fresh fruits, you want to pick something like an apple because you can basically eat the whole apple," Williams said. "There's not a lot of trash leftover. If you pick up a banana, you're left with this banana peel that's going to go into the wet trash and start to smell over a period of time."

But just not eating some foods is not the answer, Williams said. Instead, he recommends figuring out more sustainable ways to deal with waste as the goal.

For use in space, scientists have created a Heat Melt Compactor (HMC) which takes waste and makes it into tiles.

The water extracted from the waste is also used on board, and the 23-centimetre-long tiles left over from the trash are being used as radiation shielding.

This technology could greatly reduce landfill dependence and allow for the reuse of materials for other projects.

Compactors are being used on Earth, but extracting water and gases from the waste is relatively new, the book reads. In Montreal, a Biomont Energie Plant collects methane emissions from decomposing garbage and uses the gas to make electricity.

At home, a simple way to think like an astronaut is by reducing waste and trying to reuse or recycle, like donating clothing. Another more-sustainable tip is to make sure to compost leftover food scraps.

Williams believes if an astronaut mindset is implemented on Earth, sustainability will come naturally for humans ultimately reducing our harm to the planet.

"We have to develop this concept of stewardship to protect the planet for future generations," he said. "The lessons that we learn in space about sustainability and how to be efficient and how we live… can help us here on Earth."