Spaceships will need to have artificial gravity for manned Mars mission

Humans may need a spaceship with artificial gravity before they could venture to Mars, as long-term weightlessness could cause worrying changes in the brain, reveals a new study has found.

A mission to the Red Planet presents myriad technical challenges, but getting astronauts there with their brains unaffected may be the biggest of them all.

New research funded by Nasa, has found that microgravity causes the brains of astronauts to shift upwards and become squashed at the top of their skulls, piling pressure on vital neural regions.

The study found that long-term exposure to microgravity during space travel causes astronauts to develop a rare neurological syndrome in which the brain shifts upward crowding the cranium.

According to Donna Roberts, lead author of the study, which was published this week in the New England Journal of Medicine, research has shown roughly 40 per cent of astronauts return from space missions and report neurological issues.

NASA has termed the constellation of symptoms visual impairment and intracranial pressure (VIIP) syndrome.

The brain normally floats in cerebrospinal fluid, partly a function of anatomy but, also, due to gravity as per the study.

In the study 34 astronauts underwent MRI scans of their brain before and after space travel.

Eighteen of the study participants had undertaken a long journey to the International Space Station (ISS, where they spent roughly two years). The rest went on short shuttle missions lasting only a few weeks.

According to Roberts, follow-up brain scans showed virtually no changes in the brains of astronauts, who undertook short missions but ''some pretty significant changes'' in those who traveled to the ISS and stayed awhile.

The condition is typically reversible when an astronaut returns to earth with the body as the body reacclimates.