48 PHOTOS: GETTY X4, GETTY/DK IMAGES, ZHAO CHUANG, JUNCHANG LU[ GRAVITY ]
Freefalling around the Earth in orbit, or coasting
through interplanetary space on your way to
Mars, gives you the sensation of weightlessness.
You’re still moving under gravity, but it doesn’t
load your body, and this has a whole host of
knock-on effects. For example, your inner ear
can no longer help you orientate yourself,
and the redistribution of bodily fluids causes
your face to puff up and your eyeballs to distort.
But the long-term effects are more concerning.
Without the loading of gravity, your skeleton
loses calcium and becomes brittle (like with
osteoporosis). Your muscles, especially those
involved in supporting your spine and holding
you upright, deteriorate and shrink. Plus,
your heart becomes weaker when it doesn’t have
to pump blood upwards. While you remain in
a weightless environment, this isn’t too much
of a problem – and, in some senses, your body
is being adaptive in remodelling itself to life
without gravity – but it can be hugely debilitating
or dangerous when you return to the surface of
the Earth or any other planet.
In the long-term future, the solution might
simply be to generate artificial gravity for
yourself on a spaceship. If you rotate large
sections of a spacecraft – giant turning wheels
or cylinders – you can exploit the centripetal
force from the inside wall that keeps you moving
in a circle to create an apparent gravity.
We’re well familiar with this idea from sci-fi
films like 2001: A Space Odyssey, or, more
r e c ent ly, Passengers, but the problem is that
the engineering required to build such a large
rotating structure in space is pretty challenging.
In the shorter term, spacecraft might
incorporate mini-centrifuges. These wouldn’t
be large enough to walk around or work inside,Y
OU might have thought from
watching videos of astronauts
aboard the International Space
Station (ISS) that spaceships were
pretty benign environments.
Floating around in microgravity looks like
a lot of fun, and, as you’re isolated from
the rest of the human population, you’re
effectively quarantined against catching flu
or any other transmissible disease.
But, in fact, space is pretty harmful to the
human body. We evolved as social animals
under the conditions on Earth, and travelling
beyond the planet has a number of negative
effects on the body and mind.
So what are the main risks encountered by
spacefarers, and what does the latest research
have to say about how to solve these problems
for long-duration missions in the future?“WITHOUT THE LOADING OF
GRAVITY, YOUR SKELETON
LOSES CALCIUM AND BECOMES
BRITTLE, AND YOUR MUSCLES
DETERIORATE AND SHRINK”
Space
Science
L E F T: The
Dainese BioSuit
has been
designed for
trips to Mars
FACING RIGHT:
In 2001: A Space
Odyssey,
apparent gravity
was provided by
a rotating wheel
FACING FAR
RIGHT: Danish
astronaut
Andreas
Mogensen
tries out the ESA
skinsuit on
the ISS