Artificial Gravity Would Solve Many Problems with Space Travel
You've heard it before ...
Living in space is bad for you.
Bone loss. Sleep deprivation. Irregular heartbeat. Slowing of the cardiovascular system. Increased vertigo. Loss of balance.
Even increased farting (just what you want in small, enclosed spaces!).
The list goes on.
In space, astronauts experience all sorts of medical problems. And after more than fifty years of research by countless space physiologists and biologists, there is only one conclusion:
Living in space is bad for you.
The good news, though, is this -- almost all these problems are caused by one thing: the lack of gravity.
Add some gravity -- even a little bit -- and things get much better.
So the question is: if gravity is so beneficial to our bodies, why hasn't more been done to provide it in space? Where is the research? Where are the systems and technologies to counter the effects of zero-g?
Why is this critical technology being ignored?
The basic idea of artificial gravity is well understood. It's all about centripetal acceleration -- rotate an object around an axis and everything inside will be 'pushed' to the bottom.
In other words -- pseudo-gravity.
It's been a staple of scientific thought -- and science fiction plots -- for well over 100 years. In fact, Konstantin Tsiolkovsky, the Russian rocket scientist and pioneer of astronautic theory, first wrote about using a spinning wheel to produce artificial gravity back in 1903.
Additional proposals -- both fact and fiction -- have been presented since then.
In 1949, in the Journal of the British Interplanetary Society, H. A. Ross envisaged a 'refueling' station on the way to the moon. The station consisted of three sections which Ross called the 'bowl, the bun and the arm'.
The 'bowl' was a hemispherical solar collector -- a giant solar mirror -- that collected and concentrated sunlight to produce steam which in turn was used to power the station.
The 'bun' was located behind the 'bowl' and was the habitation section - a spinning wheel, in essence.
And the 'arm'? A cylindrical tube that was connected to the bun and would be used as a docking port.
It was a basic design that continued to persist well into the future.
NASA even got into the game in the '60's and 70's when it commissioned several studies. They wanted ideas on what future space stations might look like and industry giants like McDonnell-Douglas and North American Rockwell jumped in. So did academia.
Some of the concepts were huge and, in retrospect, unachievable -- more science fiction than science. Designs like the Stanford Torus, Bernal Sphere and O'Neill Cylinders.
Other designs, though, were more practical. Aerospace contractors focused on technologies that were, although bigger than anything yet flown, immediately available. Designs like the 'Space Base' proposed by McDonnell-Douglas.
Or the competing version from North American Rockwell, which housed twin nuclear reactors at one end of the station for power.
Regardless of where they came from, though, these designs all had one common theme...
It was considered essential to living and working in space.
... they were all abandoned.
David Baker, editor of Spaceflight magazine and a former NASA engineer who worked on the concepts, explained it this way:
These old space station studies now look completely archaic. The Skylab missions [of the mid 1970s] proved that the whole point of having a space station was to do microgravity research, so we abandoned the artificial gravity idea.
In other words, the prevailing thought switched from living in space to doing research in space. The effects of microgravity was what captured the scientific community's interest -- not human expansion beyond the Earth.
Now, though, after more than fifty years of medical research, the idea of artificial gravity is worth revisiting. Commercial space tourism is about to take off -- literally -- and it won't stop with quick suborbital flights. People will want a place to go and to stay.
And that means artificial gravity.
There are a few ideas that might make that happen.
One of them, first thought of during the American Gemini program, is to stretch a tether between a capsule and an unmanned docking module and then spinning the whole thing around the center to produce centripetal acceleration.
The theory is the same as twirling a bucket around on the end of a string. Go fast enough and the water will stay in.
Dr. Robert Zubrin considered doing the same thing as part of his 'Mars Direct' plan. Each hab module would detach from it's fuel tank, unreel a tether, and use the mass of the empty tank to counter-balance the hab module as it spun around in a circle.
Another idea was even simpler -- and smaller. The premise?
Use a small spinning platform -- a centrifuge -- to reproduce the effects of gravity.
Researchers at MIT, for example, conducted a series of experiments using a small centrifuge -- essentially a spinning chair or table -- to study the effects even temporary exposure to small amounts of artificial gravity would have on the body.
The problem, though, was that the short diameters of these designs tended to cause quite a bit of vertigo and motion sickness -- especially when participants moved their heads. Faster spins and shorter diameters just made it worse .
The overall result, though, was positive. Plans, therefore, were drawn up to test the system on the ISS. The hope was that demonstrating the technology in real-life conditions would lead to actual flight-ready hardware.
Unfortunately, it never happened.
But researchers kept trying out new ideas. One was to make the centrifuge just a bit bigger -- by using inflatables.
Inflatable modules have been considered for a number of years as a way to expand the volume of orbital stations, but this idea was about how to make an inflatable torus that could be used as sleeping module for a spaceship.
Called the Nautilus-X, or Multi Mission Space Exploration Vehicle, the design was put forward by a consortium from NASA, academia and industry in 2011. It essentially was a multi-billion dollar spacecraft intended for long duration missions to the moon or Mars.
The interesting thing, though, was the inflatable, rotating habitation module (sleeping module, really), or the 'centrifuge' as it was called.
The 'centrifuge' was not meant for full time habitation, nor was it designed to provide the equivalent of Earth's gravity. It was a partial-g design the astronauts would use when they slept.
The thinking was that the partial-g effects would offset the effects of zero-g and extend autonomous operations in deep space.
It was a direct expansion from the research done at MIT and it seemed doable. There was even a proposal to test it on the ISS.
An 'ISS Demonstrator' version was drawn up, including build and launch schedules (39 months from the project start) as well as preliminary budgetary estimates ($83 to $143 million USD).
This would have been the first in-space demonstration of artificial gravity, but ...
... it was canceled before it ever got beyond the initial drawing and proposal stage.
Budget constraints. Competing priorities. Politics. Who really knows?
Whatever the reason, the research into artificial gravity again took a back seat to microgravity research and the effects zero-g has on the human body.
But fear not -- all is not lost.
With the explosion in commercial space travel and space tourism, David Baker believes there may be more pressure to develop systems capable of artificial gravity. As he said in an interview with the BBC:
A hotel in space would definitely need artificial gravity. Given that 50% of people get space sickness, if we have hotels in Earth orbit then artificial gravity would be essential.
Yes it would.
The sooner the better.
What do you think? Is artificial gravity needed for our Journey to Mars? Share your thoughts in the comments below.