"Impulsive, suicidal, sexually-aberrant thrill seeker." What kind of person might that describe? A Big Brother contestant? A Base jumper? A cult leader? Guess again. It is how some US Air Force (USAF) psychiatrists, back in the early days of the space race, imagined the psychological profile of would-be astronauts. Unless they were crazy, wreckless, hedonists, the doctors reasoned, there was no way they were going to be let anyone strap them into a modified intercontinental ballistic missile and then fire them into orbit.

Of course, the men in white coats were wrong, and were guided more by their lack of knowledge about space and the tropes of science fiction than reason. Instead, the personality traits of cool-headedness under pressure, deep technical know-how and sheer physical and mental endurance – "the right stuff" of Tom Wolfe's book – ultimately led Nasa to six successful Moon landings and an utterly ingenious escape for the crew on Apollo 13, the mission that very nearly took the lives of its three crew members.

But the belief that it takes a touch of craziness to break barriers in spaceflight has never completely gone away. And with recent moves towards planning future Mars missions in the late 2020s – and even mass Mars colonisation – being labelled as akin to insanity in some quarters, such criticisms should be seen in the light of those unfounded 1950s expectations. Because without a touch of mad ambition, spaceflight will probably not progress.

The concerns over early astronaut sanity were revealed in 2011 in a research paper published by space historian Matthew Hersch, then of the University of Pennsylvania but now at Harvard, writing in Endeavour, a journal covering the societal impacts of innovation. Hersch's literature review revealed that George Ruff and Ed Levy, a pair of USAF psychiatrists working with Nasa, feared test pilot astronaut applicants "might be thrill-seekers who used fast airplanes to assauge their sexual inadequacies".

But test pilots had long been in the frame as those most likely to go into orbit. Nasa had briefly considered hiring known high-stress-handlers like mountaineers and army combat veterans to fly their spacecraft. But no group of people matched their overall requirements better than the taciturn bunch of cool-headed, tech-savvy, engineering-trained aviators from the air force, navy and marine corps. After 500 test pilot career records were examined the candidates were whittled down to 32 from which the Mercury Seven – including John Glenn, who died aged 95 in December – were chosen.

Nasa examined applicants for the astronaut program for a couple of days during that first selection in 1959 but they weren’t quite sure what they were looking for – Matthew Hersch, space historian  

Thanks to the doctors’ concerns, part of the assessment of the 32 wannabes was an extended program of psychiatric evaluation to see if the pilots were mentally fit. At the Lovelace Clinic in Albuquerque, New Mexico, Ruff and Levy, alongside two psychologists, grilled the test pilots over their personal lives and histories, gave them personality tests, aptitude exams and applied stress tests that assessed their cognitive function under isolation, noise and "other discomforts" – whatever they may have been.

"Nasa examined applicants for the astronaut program for a couple of days during that first selection in 1959 but they weren’t quite sure what they were looking for," Hersch told BBC Future. But their theories of finding impulsive, suicidal, sexual deviants were dashed: the recruits were found to be "entirely free" of such psychosis, neuroses or personality disorders.

"They were not daredevils, people with death wishes, or anything of the sort," says Roger Launius, former space historian at the Smithsonian Institution in Washington DC. "These test pilots calculated risks and made decisions based on them. On occasion, they insisted that certain changes be made to the spaceflight technology to curb the risk."

What helped fuel the concerns was the prevailing information vacuum about outer space – as nobody had been there in February 1959 when Nasa's medical and psychological tests on would-be astronauts started (Yuri Gagarin flew in 1961).  The only frame of reference that people had were science fiction novels, movies and the lurid expectations of some newspapers. The notion that humans could travel into space and not be traumatised by the stresses of the experience was "unpalatable" to large numbers of screenwriters, says Hersch, so they expected spaceflight to produce some form of oddball mental transformation.

We have seen repeatedly since the first flight in 1961 that astronauts were cool under pressure and performed effectively – Roger Launius, space historian

For instance, in the movie The Quatermass Experiment (1953) a rocket returns from orbit with two of its crew dead and another bizarrely transformed into a crazed killer by some kind of alien contact in orbit. In Conquest of Space (1955) a voyage to Mars is jeopardised by a commander who cracks under the space-induced stress and who becomes seized by a violent religious paranoia, endangering his whole crew. Concern over just what spaceflight would mean was such that even Wernher von Braun, architect of the Saturn V moon rocket, felt moved to calm fears that rockets might collide with angels or otherwise anger God, Hersch says.

Although the suspicions of sexual aberrance and thrill-seeking may sound ridiculous now, the doctors were only doing their job, says Launius. "Remember, spaceflight was entirely new and those preconditioned to look for anomalies in mental health had a duty to call out issues that they believe might adversely affect mission success."

"I could see how a psychologist might think of them as impulsive, for instance. But I think such assessments were wrong and we have seen repeatedly since the first flight in 1961 that astronauts were cool under pressure and performed effectively."

The mental strain of space exploration, however, may have entered a new phase in the 21st Century.  It is because of the proposed length of the potential Mars missions and Martian colonies, which have many commentators questioning their rationality.

In September 2016, for instance, California-based ISS cargo and satellite launcher SpaceX said that it will be able to transport 100 people at a time to the Red Planet in the largest rocket ever made – to begin spawning a viable, self-sustaining Martian civilisation. But it warns that the risk of death, especially on early missions, will be high.

Netherlands-based Mars One, meanwhile, will go a step further in the stress stakes, however, by never allowing its colonists to return to Earth: their journeys will be one-way only. These former earthlings will live out their days in Mars habitats under the enduring gaze of the reality TV broadcasters that Mars One hopes will help foot the bills.

They have to eke out an existence on a barren, freezing, radiation-zapped, dust-strewn, airless planet with bone-wasting low gravity – where crops won't grow and water is punishingly scarce

Yet some people are eager to be part of these missions – and Mars One is well into its first crew selection procedure, says its chief medical adviser Norbert Kraft, based in San Jose, California, a space psychologist who has worked with Nasa, the Japanese space agency Jaxa and Russia's Roscosmos on crew selection matters.

But have such wannabe Mars explorers lost their marbles? Perhaps: these colonial ambitions have been variously likened to madness, insanity or at the very least a charter for driving astronauts to distraction. Why? First crew members have to survive a circa six-month-long flight, a fiery atmospheric reentry and a rocket-braked landing on spindly landing legs. Then they have to eke out an existence on a barren, freezing, radiation-zapped, dust-strewn, airless planet with bone-wasting low gravity – where crops won't grow and water is punishingly scarce. It is not the most sensible of destinations.

 

Again, as in 1959, choosing the right personality types will be critical to such colonies. "Multi-year Mars missions may seem unprecedented, but we actually have a lot of experience selecting crews for long duration travel in metal tubes – the submarine force is one good example, as are the experiences of long-range bomber crews who flew together for years in some instances," says Hersch.

At Mars One, Kraft is choosing crews from the general public, not the global astronaut corps. His choice is being guided in part on his experiences observing a space mission simulation in an isolation unit in Japan – in a copy of Jaxa's ISS module, Kibo – and a 110-day eight-person simulated spaceflight isolation mission he himself took part in at Star City in Moscow, in a joint Jaxa/Roscosmos project.

Personalities come out very quickly in isolated environments – Norbert Kraft, Mars One  

In Japan, Kraft was surprised to see the standout candidate for a job as a Japanese ISS astronaut fail badly in the simulated spacecraft. "Before they went in he was the front-runner based on interviews and tests, but once inside he excluded himself from the group and had other problems – and he scored lowest in the group in the end. Personalities come out very quickly in isolated environments."

In the Moscow sim – which connected a copy of the Mir space station to a cod Mars ship – the full force of a culture clash struck. Some candidates upset others by openly watching porn films on their computers, and others by fist fighting to the point of drawing blood – completely traumatising their more civilised colleagues. "Getting the right gender and culture mix is important," Kraft says. "People are the problem, not the environment."

So, especially for non-return missions like the proposed Mars One venture it is definitely not a case of choosing impulsive, thrill-seeking, sexual deviants. "The key is picking people without personalities," says Hersch. "The duller the better."

Whether that will make for watchable reality TV from Mars, however, only time will tell.

Join 800,000+ Future fans by liking us on Facebook, or follow us on Twitter, Google+, LinkedIn and Instagram

If you liked this story, sign up for the weekly bbc.com features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, Travel and Autos, delivered to your inbox every Friday.