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January 2021
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Anyone for Mars?

By David E P Dennis FCIPD LCGI RAF – Arachnoid Articles


On clear nights it is easy to see Mars, reddish and distant. The planet is around half the size of Earth and the pull of gravity is far less than on our planet.  Astronauts travelling to Mars would be weightlessly suspended in what is called ‘microgravity’. With the latest US unmanned spacecraft ‘Curiosity’ on the surface and its discovery of substantial water within Martian soil, there has been pressure on NASA to consider a manned expedition to Mars. A separate private investor-funded project called ‘Stichting Mars One’ is encouraging people to volunteer for a seven-month one-way trip as ‘colonists’. Four colonists would go in 2023. Many others would follow.

What are the problems of such a journey? Can humans really survive a trip to the Red Planet and get back to Earth?  What about radiation – or micrometeorites puncturing the hull of the ‘ship’? How many people should go to set up a viable permanent colony? These are typical questions from children and adults alike. But there is one deeply relevant question that most people never ask: ‘What happens to the cerebrospinal fluid surrounding your brain and spine on a Mars trip?’

This question and its response are absolutely critical to the human exploration of Mars and as Chair of the national medical charity IIH UK ( I am deeply involved in thinking about the problems experienced by US astronauts who have suffered medical setbacks in space.  IIH UK is a member of the NASA Human Health Programme. We have corresponded with NASA and with the University of Ohio scientists who have been working with NASA. I have made a formal proposal to NASA and JPL Pasadena for an experiment to be placed on the next NASA spacecraft in 2020.

It makes sense to highlight the central problem of naivety for any member of the public who thinks that they can go to Mars without facing the very greatest difficulty or even death. On the 13th September 2013 the BBC ran a headline:

US man volunteers for one way flight to Mars

The article said:It is the trip of a lifetime – for a lifetime. US man Aaron Hamm has volunteered to fly one-way to Mars, despite no prospect of ever returning to earth. The trip is run by the Dutch Mars One project, which hopes to create a permanent community of settlers on the red planet in 2023. Radiation exposure is a concern, and travellers could never readjust to the Earth’s gravity afterwards. But Mr Hamm is determined to take the flight. He told BBC Radio 5 Live’s Breakfast: “Wanting to go somewhere genuinely new… and be a part of something that’s really about humanity’s future is something I’ve always wanted to do.”

Also in September 2013 the BBC stated that 850 Irish people wanted to go one-way to Mars:

‘The Irish applicants are among 202,586 people from around the world who have expressed their interest in taking part in the Mars One project.’

Plainly a great many people are interested in going to Mars and staying there. But some US astronauts have had a dreadful time just living in microgravity on the International Space Station (ISS). At the four month point and thereafter, at first seven astronauts and then 27 astronauts experienced vision problems, severe headaches, memory loss and general operational competence problems due to an effect called ‘celephad shift’.

Each human and most animals that can stand or rear upright have membranes around their brain and spine which hold a clear liquid called cerebrospinal fluid (CSF). On Earth this circulates and refreshes every five to seven hours. The CSF is made in the brain and cleans it, taking unwanted products back to the blood via various routes. In microgravity the CSF rises upwards and pools in the head causing an overpressure in a bony skull with fixed capacity. The pain and discomfort and severe vision problems (papilloedema) are similar to that suffered by IIH patients on Earth – IIH being Idiopathic Intracranial Hypertension.

So going to Mars will depend on a great number of as yet unassessed aspects.  Let us take some of them.  In 1971 and 1975 two science papers were published which showed that not all humans are born with all the means to transfer CSF to the blood. In the first instance two children who died were found to have no ‘villi’ or ‘granulations’ – the tiny organs that allow the CSF to revert to the blood. These are normally located inside the skull at the top of the head in an area called the supersaggital ridge. By the time you are 4 years old you will have around 50 ‘granulations’. In 1975 it was reported that of 14 individuals with CSF pressure problems, 11 had no granulations.

It is thought the granulations are formed by genetic instructions from stem cells. If the stem cell instruction is imperfectly enacted a person may not have all the ‘villi’ or ‘granulations’ required to pass the CSF back to the blood at the same rate as it is formed, thus causing an overpressure. Of those with IIH, 25% of men go blind and 12.5% of women also lose their sight.

The normal rate of incidence of IIH in humans is 1 or 2 in 100,000 and for obese women of child-bearing age it is around 20 in 100,000. So, for male and female non-obese non child-bearing age colonists numbering a potential 200,000 or more we might expect four to get IIH. With women colonists of child-bearing age we might expect a few more with problems.

But that is not what actually happens. Celephad shift is not IIH. It is a physical movement of fluid upwards for everyone who is weightless. There is only a small pool of US astronauts numbered in the hundreds and yet 27 of them have already had a dreadful time. Let us say that some 300 astronauts have worked on the ISS and 27 of them have become ill. That is a rate of 11%.

Now apply 11% to 200,000 and you can see that we are in trouble with our Mars colonisation. If they all go over time, then twenty-two thousand colonists could become ill with celephad shift problems. Some could be captains, navigators, engineers who want to ‘boldly go’.

What can we do?  This article is not long enough to cover all the routes that CSF takes back to the blood, but IIH UK is already designing research into the monitoring of the number of human granulations that most people have and ensuring that with IIH there will be a way of telling people if they have enough effective granulations. This check needs to be done for all astronauts. If a colonist’s granulations have not grown sufficiently or if they are blocked by old brain products and salts, then these people are ‘high risk’ and should not go to Mars.

The IIH UK position is that while we fully support NASA and human exploration of Mars, we think it is being  ‘rushed’ and that unnecessary pressure is being placed on members of the space programme to ‘boldly go’ when they really should be waiting until celephad shift problems are controllable.

IIH UK has proposed in writing to the NASA Chief scientist that all long distance spacecraft should be rotated to induce artificial gravity – or the sleeping/resting couches of the crew should be rotated to enable the CSF to move back towards the feet. NASA astronauts will stay on Mars and come back again so their weightless or partial weightless time will be some 17 or 18 months.

The next major problem for the colonists is that Mars is smaller so gravitation is far less. So when they live permanently on the surface of Mars there will still be a constant celephad shift of CSF towards the head, and unless their sleeping couches are rotated to move the fluid back down the body, many of them will have dreadful headaches and severe sight problems for the rest of their lives on Mars.

Mars is not going to go away – let’s not rush towards it.

If you would like to discuss this or know more about the problems please email Arachnoid Articles at

I cannot promise to answer every email instantly but I will do my best!

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