Testing the Value of Artificial Gravity for Astronaut Health

Control room of DLR’s short-arm centrifuge (Credit: ESA)

COLOGNE, Germany, 21 March 2019 (EXSA PR) — Test subjects in Cologne, Germany will take to their beds for 60 days from 25 March as part of a groundbreaking study, funded by European Space Agency ESA and US space agency NASA, into how artificial gravity could help astronauts stay healthy in space.

Carried out at the German Aerospace Center’s (DLR) :envihab facility, the long-term bedrest study is the first of its kind to be conducted in partnership between the two agencies. It is also the first to employ DLR’s short-arm centrifuge as a way of recreating gravity for participants.

But just how easy is it to stay in bed for 60 days and what is the relevance of adding artificial gravity for space researchers? We pull back the covers on this unique investigation as preparations get underway.

Bedrest has long been used to mimic some of the changes our bodies experience in the weightlessness of space. Humans are made to live on Earth and without the constant pull of gravity it is common for muscles and bones to start wasting away.

Bedrest study bed at :envihab (Credit: ESA)

Currently, astronauts on board the International Space Station exercise for up to 2.5 hours per day and maintain a balanced diet to help mitigate microgravity’s effects, but scientists believe adding a dose of artificial gravity could be key during longer-term missions.

Though it may sound simple for the 8 male and 4 female volunteers involved, lying in bed for a full 60 days, plus a further 29 days of acclimatisation and recovery, is not quite as restful as it seems.

Throughout the course of the study, all 24 participants will need to remain at :envihab on the DLR campus. There they will be kept in beds with the head end tilted 6° below horizontal and must ensure one of their shoulders is touching the mattress at all times.

As blood flows to their heads and muscle is lost from underuse, researchers will investigate changes and test techniques from diet to physical exercise. Artificial gravity is one of the techniques under the spotlight this time around and will see some of the participants sent spinning.

Short-arm centrifuge at DLR’s :envihab facility (Credit: ESA)

Once a day, a selection of the study’s participants will lie in DLR’s short-arm centrifuge. There they will be spun to encourage blood to flow back towards their feet and allow researchers to understand the potential of artificial gravity in combating the effects of weightlessness.

The intensity of the centrifugal force is able to be adapted to each person according to their size. DLR can also adjust the centre of spin so that subjects are spun around their heads or their chests. Changing the position in this way could have far-reaching consequences for rehabilitation but, as this is a new domain, these consequences are currently unknown.

A number of different experiments will be carried out over the course of the study, looking at cardiovascular function, balance and muscle strength, metabolism and cognitive performance among other factors. Seven of these experiments will be conducted by European-led research groups, with a view to validating the findings on the International Space Station during future missions.

ESA team leader for research Jennifer Ngo-Anh says the international nature of the long-term bedrest study reflects the international collaboration necessary as ESA plans future missions to the Moon and beyond.

“To make these missions possible, various risks to astronaut health must be minimised. This study allows us to address the issue of muscular atrophy caused by weightlessness, but also other stressors such as cosmic radiation, isolation and spatial restrictions.”

  • Saturn1300

    They could just stand up. More than 1G with a centrifuge may be harmful and not help at all. They had better be careful. It is cheap, but I do not think it will replace spinning a Spaceship. Shotwell is suppose to be thinking of ways to make money for SpaceX. She could have used DragonLab. A tether and a weight and spin. Some more LOX in the Trunk for a 30 or so day mission at Mars and Moon gravity. Then they have the information they need for living on Mars. Then offer the info for sale. NASA and other space agencies should pay to get the info. Should not have cost them much with F9 and Dragon1. Would have cost more in ’12 until they got to reuse F9. But they had Dragon1. And Space fans would have had Crewed flight. If they could get a launch license from FAA. Did not have to worry about NASA specs. Insurance cost too much maybe.

  • gunsandrockets

    I applaud this experiment, and look forward to the results. But the limitations of bed rest studies are obvious. What we really need is low gravity experiments where people can walk around, work, eat and sleep as normal, and for continuous periods of 6 months or more.

    So this is as good a place as any to advocate for an artificial gravity LEO manned habitat. But no pie in sky idea have I. I propose a simple near-term single-launch no-orbital-assembly architecture, using the SLS to do the job, exploiting the overall length and mass of the SLS core stage, the core retained in LEO as a counterweight for the spinning habitat. No trusses, tethers, or other schemes necessary since the payload stays attached to the core.

    As long as we are paying for the damned SLS, we might as well exploit to the maximum its size, mass, payload mass, and payload volume. I don’t expect the SLS program to last beyond five launches before it is cancelled. I hope at least one of those launches will be for a LEO spinning space station.

  • gunsandrockets

    A tethered Dragon Lab would be an excellent exploit for a tethered hab low gravity experiment. But for animal studies rather than human.

  • Saturn1300

    Gemini did it.

  • Saturn1300

    Good idea, but expensive. Dragon1, weight, cheap. Make some money for SpaceX maybe.

  • Jeff2Space

    Yes, but that was a very low spin rate, so not much in the way of G forces. A quick web search says 0.00015 G.

  • gunsandrockets

    You aren’t going to get human data we need from a mere Dragon Lab.

    We need human experiments that last for at least six months (and ideally even longer) of continuous low gravity, on the scale of Martian or Lunar gravity. That means something really big. Something that big is inevitably expensive.

    In fact, that project is something so expensive no one is making any (plausible) suggestion to even try and do it. That’s why I am suggesting my SLS scheme. I think I see an opportunity for NASA to make that expensive project plausibly affordable.

    The SLS is a boondoggle. An expensive sacred White Elephant. The SLS program will inevitably collapse, once enough people in Congress are brave enough to admit the truth about ‘The Emperor’s New Clothes’. I’m guessing there only be two to five flights of the SLS before it is cancelled.

    But for an orbital launch vehicle the SLS has weird and unique characteristics as a consequence of its Space Shuttle heritage. Characteristics that make it peculiarly suitable for a single launch rotating habitat mission. My hope is that before the SLS program collapses that NASA will exploit its unique character.

  • duheagle

    I’m afraid NASA has largely given up doing useful stuff – at least anent human spaceflight.

  • duheagle

    Well, at least we know whether or not humans can survive in the gravity fields of Bennu and Ryugu. Deimos and Phobos are still question marks though.

  • gunsandrockets

    Expanding on your Dragon Lab low-gravity-tether concept:

    Dragon Lab is too small for useful human experiments. But 10 cubic meters is plenty of space for small animal experiments. But how large an animal? How many? For how long in space?

    I think rhesus monkeys, might make for interesting test subjects. Perhaps 2-4? For 30 days? With individual enclosures that allows them to move around and feed normally while Dragon Lab is in orbit?

    The US and Russia actually did a microgravity experiment with rhesus monkeys back in 1996.

    https://lsda.jsc.nasa.gov/Experiment/exper/827

    Perhaps one of the biggest problems with doing monkey experiments is political rather than technological/economic, as seen by the US withdrawal from the Bion 12 mission.

    https://lsda.jsc.nasa.gov/Mission/miss/135

    A more modest concept than freely moving monkeys, might be a larger version of the Martian Greenhouse that Musk originally wanted to do back before SpaceX existed. But using Dragon Lab in LEO to simulate martian gravity.

    Perhaps it could even be a sort of terrarium with a mix of animals of plants? A miniature version of Biosphere 2? Could you get useful data from a mess like that?

    Maybe that’s a bad idea, only good for a publicity stunt. A publicity stunt that costs over 60 million dollars. Yeah, and a stunt that could backfire badly too if the terrarium dies horribly. Yeah, scratch that idea right off the list!

  • gunsandrockets

    Hey, things could be much worse. Think where NASA was stuck, back around 2002. At least now NASA makes noises about going beyond LEO.