People intending to travel somewhere exotic – a region, for instance, without an abundance of working toilets – accept the necessity of sometimes painful vaccinations to protect them against nasty diseases.
In years to come, as space travel becomes a viable option, pre-flight medical procedures are quite likely to become significantly more drastic.
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"I think that even when you go on a mission to somewhere like Antarctica they recommend you get your appendix out," said US astronaut Carmel Johnston.
"I can't imagine why people would have an appendix if they were going to Mars. That's just asking for trouble. The removal of organs might be helpful. Your spleen, your wisdom teeth – there are a couple of useless items we have in our bodies that can be removed without inviting trouble later on."
![NASA scientist Carmel Johnston spent a year living in a Mars biosphere.](/web/20170226131332im_/http://www.smh.com.au/content/dam/images/g/u/i/i/s/r/image.related.articleLeadwide.620x349.guebvu.png/1488015070654.jpg)
Of late, Johnston has had plenty of time to think about life on Mars. This is primarily because she recently spent a year living there.
Well, not exactly, of course. We might have heard a bit about it before now if she had been on the actual Red Planet. Johnston, in reality, spent 12 months living in a state-of-the-art simulation of a likely Mars early settler house – a small dome shared with five other people near the top of the barren Mauna Loa volcano in Hawaii.
The dome, known as the Hawaii Space Exploration Analog and Simulation (or, in a possibly unintended example of irony, HI-SEAS) is a facility managed jointly by the University of Hawaii and NASA.
It is designed to test how people cope in isolated, extreme and confined environments – just the sort of place, in other words, that Martian first fleeters will be confronted by when they arrive.
![NASA scientist Carmel Johnston says there were some definite health benefits to being stuck in a closed environment 2500 ...](/web/20170226131332im_/http://www.smh.com.au/content/dam/images/g/u/i/i/s/t/image.related.articleLeadNarrow.300x0.guebvu.png/1488015070654.jpg)
Johnston and her colleagues lived together in a cramped 111 square metres of floor space. There were six tiny sleeping cubicles up in a loft, a kitchen, two bathrooms, a shower and an exercise area.
For most of the time, they all stayed indoors. Every week or so, two of them were allowed outside for a walk while wearing a bulky space suit, mimicking exploration of the planet surface.
Communication with the outside world was by email only – with a 20-minute delay built in to simulate the time it takes for signals to travel between earth and the real Mars.
In one very important way, the HI-SEAS adventurers – earth-bound astronauts, as they prefer – were fortunate. During their entire time on the volcano none became seriously ill, nor sustained any injuries worse than a bruised knee.
In real life, even with the massive resources of NASA behind them, it would have taken half a day to get an ill or injured crew member to the nearest hospital.
On Mars, even if it were feasible, round-trip evacuation could take up to 600 days.
"If you break your leg on Mars it would be a very important thing," said Johnston.
"I believe you would have some medical training on your crew so you would be able to either stabilise the injury enough to have someone telecommute in and tell you what to do. Or you may have someone on the crew who can do surgery.
"You will have to have all those skills yourself. You have to, because you're not going to send someone all the way back to earth just because of broken leg. You're going to fix them up, put them on bed rest, and supervise their recovery."
Depending on your disposition, it's a thought that brings to mind either the slick medical bays of the USS Enterprise, or the rough-hewn wooden tables and saw-wielding barber-surgeons of Cook's HMS Endeavour.
There were, however, some definite health benefits to being stuck in a closed environment 2500m above sea level for a year.
"We were completely isolated, so we weren't introduced to the flu or other conditions that were going around the world that we would have been exposed to otherwise," she said.
It's an interesting observation. NASA is on course to send people to land and perhaps live on Mars as early as the 2030s. Assuming they were properly screened and healthy at take-off, they could constitute the first-ever human community to be permanently free from viral diseases.
Other misfortunes, though, will still occur: strokes, aneurisms, cancers, accidents, perhaps even serious injury through violence. Johnston's mission, after all, was designed to test tolerance in confined spaces.
There were tensions, conflicts and arguments, even among people who knew all they had to do to escape was walk outside and call in a helicopter.
When such things happen, as they eventually will, decisions need to be made. The very ill contribute nothing and consume scarce resources. You can't call the ambos and get them to the hospital.
"You would probably need a protocol for end of life issues," she said. "I know even for us we were several hours from help. In some places, like Antarctica, you can be days away from medical care if you have an aneurism or something like that. You could pretty much die right on the spot.
"That pretty much could have happen to any one of us, and we were lucky that it didn't."
Johnston and her colleagues came down from Mauna Loa at the end of August, after which she returned to her home in Montana. Next month she is heading this way for appearances in Sydney, Melbourne in Adelaide.
Travel changes people, creating and destroying hope and expectation in equal measure. Johnston is one of very, very few people who have experienced – even if by proxy – life on another planet.
Having done so, should NASA call and offer her passage to the real Red Planet, would she go?
"It depends on what year it's occurring in," she said. "If it's today, no way. It's just not realistic. If it were to happen in 20 years, I might be too old. I might raise my hand anyway, just for the fun of it, but there's a really good chance I wouldn't be selected."
Carmel Johnston will appear at the Sydney Opera House's All About Women festival in Sydney on March 5, the Wheeler Centre in Melbourne on March 6, and WOMADelaide's Planet Talks in Adelaide on March 11.