In the film 2001: A Space Odyssey, Stanley Kubrick’s spacecraft spins through the solar system like a giant, futuristic ferris wheel. The rotating craft has a suitably epic quality and, through the centrifugal force, conveniently explains why there appears to be gravity inside the spaceship.

In real life future astronauts may have to settle for a slightly less cinematic form of artificial gravity, however. Space scientists working on the problem have developed a large vacuum cleaner-like device that seals around the astronaut’s waist, creating the impression of weight on the lower body through a powerful suction force.

Alan Hargens, an orthopaedic surgeon at the University of California, San Diego who helped develop the lower body negative pressure (LBNP) device, describes it as “an early form of artificial gravity”.

“A centrifuge is probably the best thing we could give the astronauts, but it’s very expensive and there are also some safety issues with having a rotating device on a spacecraft,” he said. “This device works like a vacuum cleaner, so the person can exercise at their normal body weight.”

The lower body negative pressure (LBNP) device, described by orthopaedic surgeon Alan Hargens as “an early form of artificial gravity”. Photograph: John Charles/Watenpaugh et al

Space agencies are investigating ways to simulate gravity because weightlessness causes a range of health problems for astronauts, including back pain, muscle and skeletal weakness and fluid pooling in the upper body. Even readjusting to pressure on the feet and buttocks can be uncomfortable when astronauts return to Earth – or, in the future, land on Mars.

“Crews get very little of this type of loading so their butts and feet are hypersensitive to touch after six to twelve months in space,” said Hargens.

Astronauts have tested the device in ground-based studies and it has been shown to counteract muscle and skeletal problems in studies involving prolonged bed rest – a proxy for spending time in low gravity.

In one trial, 15 sets of identical twins spent 28 days resting in beds tilting slightly head down. In each pair, one twin was assigned to a non-exercising group and the other spent 40 minutes each day exercising in the LBNP machine on a vertical treadmill - the suction force allowing them to run horizontally. The study found that back muscle strength decreased significantly in the non-exercising group, but was maintained in the twins who exercised.

Facebook Twitter Pinterest The LBNP device in action.

Hargens and colleagues believe a compact, collapsible version of the device could be used on an extended space mission to the moon or Mars.



“For crew mental wellbeing, the system could include a virtual environment to simulate walking and running with family members on the beach or in mountains,” said Hargens. “Importantly the concept would also allow normal weight-bearing in seated posture on a prolonged mission using the suction pressure to reproduce the posture that we assume 12 to 16 hours each day on Earth.”

The Russian space agency, Roscosmos, has developed a similar concept called the Chibis suit, with an appearance akin to Wallace and Gromit’s Wrong Trousers, that has already been tested on the International Space Station (ISS). Although this is mostly aimed at reversing the accumulation of fluids in the head and torso, and cannot be used for exercising. The Chinese space agency has another version - a device also developed in Hargens’ lab - that looks like a vertical concertina worn by astronauts with a pair of braces. By doing squats the astronaut pumps the device up and down creating their own vacuum.

Facebook Twitter Pinterest The Chinese space agency’s version of a vacuum suit. By doing squats the astronaut pumps the device up and down creating their own vacuum. Photograph: Watenpaugh et al

Exercising without gravity is challenging because weights are almost weightless. So instead of pumping iron, astronauts work out using bungee ropes, but these do not match the force distribution on the body felt on Earth and, probably as a result of this, astronauts have incurred injuries on the ISS exercise station.

Professor Lewis Dartnell, an astrobiologist at the University of Westminster, said the human body rapidly adapts in space by shedding muscle and bone mass. “Your spinal muscles, buttock muscles, quads, are all used for holding your posture against gravity and for walking,” he said. “You have to build those up again over time when you return to Earth.”

Astronauts generally enter a lengthy period of rehabilitation on return to Earth after a stint in space. However, this would not be practical on any future Mars mission. “You will have spent five or six months in space, your body has gone through all this and you land on Mars, where you do not have hospitals and medical teams,” said Dartnell.

Hargens and colleagues argue that their device might solve many of the physical problems encountered in space. “But it will take convincing some of the space agencies,” he acknowledges.

• This article was amended on 28 November 2016. An earlier version referred to centripetal force in the first paragraph when centrifugal force was meant.