SPACE TRAVEL and HEALTH
A
Space biomedicine is a relatively new area of research both in the
USA and in Europe. Its main objectives are to study the effects of space
travel on the human body, identifying the most critical medical prob-
lems and finding solutions to those problems. Space biomedicine centres
are receiving increasing direct support from NASA and/or the European
Space Agency (ESA).
B
This involvement of NASA and the ESA reflects growing concern that
the feasibility of travel to other planets, and beyond, is no longer limited
by engineering constraints but by what the human body can actually
withstand. The discovery of ice on Mars, for instance, means that there is
now no necessity to design and develop a spacecraft large and powerful
enough to transport the vast amounts of water needed to sustain the
crew throughout journeys that may last many years. Without the neces-
sary protection and medical treatment, however, their bodies would be
devastated by the unremittingly hostile environment of space.
C
The most obvious physical changes undergone by people in zero grav-
ity are essentially harmless; in some cases they are even amusing. The
blood and other fluids are no longer dragged down towards the feet by
the gravity of Earth, so they accumulate higher up in the body, creating
what is sometimes called ‘fat face’, together with the contrasting ‘chicken
legs’ syndrome as the lower limbs become thinner.
D
Much more serious are the unseen consequences after months or
years in space. With no gravity, there is less need for a sturdy skeleton to
support the body, with the result that the bones weaken, releasing calci-
um into the bloodstream. This extra calcium can overload the kidneys,
leading ultimately to renal failure. Muscles too lose strength through
lack of use. The heart becomes smaller; losing the power to pump oxy-
genated blood to all parts of the body, while the lungs lose the capacity
to breathe fully. The digestive system becomes less efficient, a weakened
immune system is increasingly unable to prevent diseases and the high
level of solar and cosmic radiation can cause various forms of cancer.
E
To make matters worse, a wide range of medical difficulties can arise
in the case of an accident or serious illness when the patient is millions
of kilometers from Earth. There is simply not enough room available
inside a space vehicle to include all the equipment from a hospital’s
casualty unit, some of which would not work properly in space anyway.
Even basic things such as a drip depend on gravity to function, while
standard resuscitation techniques become ineffective if sufficient weight
cannot be applied. The only solution seems to be to create extremely
small medical tools and ‘smart’ devices that can, for example, diagnose
and treat internal injuries using ultrasound. The cost of designing and
producing this kind of equipment is bound to be, well, astronomical.
F
Such considerations have led some to question the ethics of investing
huge sums of money to help a handful of people who, after all, are will-
ingly risking their own health in outer space, when so much needs to be
done a lot closer to home. It is now clear; however, that every problem
of space travel has a parallel problem on Earth that will benefit from
the knowledge gained and the skills developed from space biomedical
research. For instance, the very difficulty of treating astronauts in space
has led to rapid progress in the field of telemedicine, which in turn has
brought about developments that enable surgeons to communicate with
patients in inaccessible parts of the world. To take another example, sys-
tems invented to sterilize waste water on board spacecraft could be used
by emergency teams to filter contaminated water at the scene of natural
disasters such as floods and earthquakes. In the same way miniature
monitoring equipment, developed to save weight in space capsules, will
eventually become tiny monitors that patients on Earth can wear with-
out discomfort wherever they go.
G
Nevertheless, there is still one major obstacle to carrying out studies
into the effects of space travel: how to do so without going to the enor-
mous expense of actually working in space. To simulate conditions in
zero gravity, one tried and tested method is to work under water, but
the space biomedicine centres are also looking at other ideas. In one
experiment, researchers study the weakening of bones that results from
prolonged inactivity. This would involve volunteers staying in bed for
three months, but the centre concerned is confident there should be no
great difficulty in finding people willing to spend twelve weeks lying
down. All in the name of science, of course.