If you’re squeamish, stay on Earth!

Wednesday, 31 October 2012

On Sunday night, at around twenty past nine, SpaceX's Dragon spacecraft returned to Earth from the International Space Station, safely splashing down about 400 kilometres off the coast of southern California.

The mission, called CRS-1, began October 7, when the Falcon 9 rocket launched Dragon from Cape Canaveral Air Force Station.

Dragon returned with 0,75 tons of return cargo including hardware, supplies, and a freezer packed with scientific samples. It was a relatively trouble free mission apart from a glitch with one of the launch engines which was quickly and safely compensated for by on-board computers.

All of this is cause for great excitement for me and the more than 120 000 people who have tracked the mission from the start on an almost 24 hour basis. SpaceX's business objective is to revolutionise space transportation, with the ultimate goal of enabling people to live on other planets.

The great challenge in travelling the vast distances of the universe is in keeping us alive in a self-sustaining cocoon that will provide us with air, water, and food with no access to an outside source of any of those. The only conceivable way one could do this successfully is to recycle everything, including water.

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It's already being done on the International Space Station where Environmental Control and Life Support System (ECLSS) helps astronauts use and re-use their precious supplies of water.

The ECLSS Water Recycling System (WRS), developed at the Marshall Space Flight Center, reclaims waste waters from the Space Shuttle's fuel cells, from urine, from oral hygiene and hand washing, and by condensing humidity from the air.

Without such careful recycling 20 tons per year of water from Earth would be required to resupply a minimum of four crew members for the life of the station.

Research animals are also part of the recycling loop. "Lab animals on the ISS breath and urinate, too, and we plan to reclaim their waste products along with the crew's. A full complement of 72 rats would equal about one human in terms of water reclamation," says Layne Carter, a water-processing specialist at the MSFC.

Not surprisingly, water leaving the space station's purification machines is cleaner than what most of us drink down here on terra firma.

And against this backdrop comes this storm in a teacup from Durban around plans to recycle sewage water for drinking purposes.

Do you see how these two things are related?

Water, all water, that cup of coffee you had for breakfast or that glass of wine you will have with your dinner, all of it has at some point over the millennia passed through the digestive tracts of animals.

In most cases, water from urine or faecal matter evaporates and returns to the ground in the form of rain – a natural process of distillation which in the absence of pollution would give us pure water.

In our modern industrialised world, pollutants in the atmosphere are dissolved as the rain falls, resulting in some cases in acid rain.

Urine in the soil is converted by microbes into a form that plants can absorb and use as fertiliser. The soil also acts as a filter, leaving behind water which is absorbed by the plants into that juicy fruit you bit into for dessert.

The systems built for the ISS try to mimic that natural cycle using technology instead of microbes. Even so, it's still not 100 percent effective in conserving water – some gets lost every time an astronaut takes a spacewalk for example.

And so we now find ourselves imagining a future where journeys to other solar systems will take years. A natural consequence of this is that people may well die during the journey.

What do you suppose would need to be done with the body?

The fact is that the human body is mostly made up of water, and there can be no question of jettisoning the body into space to waste such a precious resource.

So if you are squeamish about drinking recycled water, by all means spend massive amounts of money on buying a personal desalination plant and drive to Durban's Blue Lagoon to fill up with sea water.

Oh, did I mention that the uMgeni river flows into the sea there? Do you know what humans and other creatures do further up that river?

The interesting evolutionary point will come with those who have religious or cultural objections to drinking recycled water. They will never get to travel to outer space.

And perhaps, that's not such a bad thing.