During the earliest days of crewed spaceflight, many doctors harboured concerns about what effects zero-gravity would have on the human body.
While many of these concerns did not and have not come to fruition, one particular problem continues to linger: ‘Space Adaptation Syndrome’ (SAS).
Characterised as a type of motion sickness, NASA describes SAS as occurring because of ‘conflicting messages about body position and movement which the brain receives from the eyes, the balance organs of the inner ear and gravity-sensing receptors in the muscles, tendons, and joints’. It is similar in many ways to sea-sickness or car-sickness.
In the US, astronauts had not suffered from SAS before the Apollo programme because the command module was the first American spacecraft that gave the astronauts proper freedom of movement. The previous Mercury and Gemini spacecraft hadn’t enough room for them to stretch their legs, much less float around.
Although it wasn’t known at the time because of the secrecy of the Soviet space programme, cosmonaut Gherman Titov was the first person to suffer from SAS. In 1961 Titov became the second person to orbit Earth and, at 25, the youngest person ever in space. He was sick several times.
The first case of SAS in an American astronaut was most likely Apollo 8‘s Frank Borman. Although he chalked it up to the ’24-hour flu’ or an adverse reaction to a sleeping tablet at the time, Borman suffered from vomiting and diarrhoea for a few hours in the opening phases of the mission.
Rusty Schweickart of Apollo 9 also suffered from SAS. His condition was bad enough to prompt the mission’s commander, Jim McDivitt, to cancel a spacewalk that Schweickart was slated to conduct. It was too much of a risk to put Schweickart inside a pressurised spacesuit if it was likely he would be sick, as he could asphyxiate and die.
Although Schweickart recovered and did conduct his planned spacewalk, he never returned to space as a result of having suffered from SAS. He submitted himself to NASA’s doctors – becoming what he described as a ‘motion sickness guinea pig’ – to help them conduct studies into the condition that might help future astronauts.
Other Apollo astronauts also reported brief feelings of nausea early on in their missions – including Apollo 11’s Mike Collins, Apollo 13’s Fred Haise, and Apollo 17’s Jack Schmitt – but none were actually sick.
Instances of SAS also occurred in crews visiting Skylab, the first American space station. All three crewmembers of the second Skylab mission felt nauseous in the early stages of their 59-day-long mission. That included Alan Bean, who had previously flown to and landed on the Moon during Apollo 12 with no adverse effects.
There is even a scale that astronauts suffering from SAS are jokingly ranked against. It was created ‘in honour’ of Jake Garn, the first sitting member of Congress in space. He flew onboard Space Shuttle Discovery during mission STS-51-D in 1985 and suffered so badly from SAS that ‘one Garn’ came to be informally known as the highest level of sickness it is possible to experience in space.
It is estimated that one in three spacefarers will suffer from SAS at some point during a mission. There is seemingly no rhyme or reason for who it will and won’t affect, nor any way of preventing it save for recommending that astronauts keep head movements to a minimum until they acclimatise to being in space. As long as humans continue travelling into space, it will no doubt continue to be a thorn in their sides.