Space Foundation
Environmental Challenges
Not long ago, some people doubted whether
any living thing, much less a human, could
even survive a journey into space.
 Past human space flight missions have
demonstrated that humans can survive
space flights of several months, even up to a
year in duration.
 How long can humans live in space, and
how effectively can the work in space?

Write it down
What are three main differences
between the Earth’s environment and
the environment of space that would
affect the human body?
Major Differences
Space has no atmosphere.
 Space does not have an atmospheric
filter to help shield humans from
radiation exposure.
 Humans experience less gravity in
space than they do on Earth. (Free fall
on the ISS and shuttle)

Human Body
The body is an integrated system.
 Systems are in constant communication
with each other and interdependent on
each other.
 On Earth our body establishes an “Earth
Normal” condition.
 In space our body adjusts to establish a
“Space Normal” condition.

ISS and Space Shuttle

The shuttle and ISS are designed to keep
the astronauts as comfortable as
possible—the ISS modules are roomy,
bright, and kept at a constant 70 degrees
Fahrenheit.

Despite the amenities provided, life in
space requires considerable acclimation.
Space Adaptation Syndrome
Experienced by ¾ of all astronauts in
“weightlessness.”
 More commonly known as “space
sickness.”
 Form of motion sickness

The Vestibular System

Located in the inner ear, “the balance
organ.”

Helps your brain process information on
how you move to help you determine the
orientation of your body
Quick Adaptation
Because the sensation of
“weightlessness” is constant, the body
and the brain adapt quickly to their new
functions and begin to work together
relatively quickly.
 Symptoms of space sickness seem to
subside after the first few days of the
mission.
 Not all systems adapt so quickly!

Food

Space sickness usually involves a dramatic loss
of appetite, but eventually the astronaut begins
eating again. When that happens, there are
many challenges for the first-time visitor to the
ISS.

Meals on space stations present a myriad of
problems because of weightlessness, a
shortage of storage space, spoilage, and a
shortage of water for food preparation.
Café ISS

Ed Lu, the American commander on the
ISS, enjoyed working on the space station
as well as eating on it. While in space on
the ISS, he wrote an article about food
titled "Eating at Café ISS" for NASA's Web
site. In the article, he describes some of
the more interesting and amusing
experiences of dining in a weightless
environment.
Space Food
Most foods are dehydrated to conserve
space and are packed into
compartments for storage.
 Water, one of the most precious
commodities, is problematic since it
cannot be compressed; it is also one of
the heaviest commodities.

 Water recapture and recycling equipment.
Space Food
Initially prepared, cooked, and packaged
on Earth.
 Processed to make it stick to a spoon.
 Avoid crumbly foods.
 Thick foods like sauces, pastes, peanut
butter, and moist cake batter are used to
bind flaky foods together.

 Tortillas are preferred to slices of bread
because they create few crumbs.
Space Food
Easy prep
 To avoid spoilage

 Freeze-dried
 Low-moisture
 Thermo stabilized
Nutrition
Eat 3 times a day
 Expend less energy, need fewer calories
 Nutritionists work with individual
astronauts to create a healthy menu.

Living in Space
The changes that occur to the human
body while on the ISS are appropriate
for the environment of space, but may
be inappropriate for Earth.
 The human body reacts as if the change
will be permanent, even though it will
returning to Earth shortly.

Effects on the Body
Bone Loss
 Decrease in muscle tissue
 Decrease in heart size
 Puffy-Head Bird Leg Syndrome

Bones
Bone is living tissue.
 Bone is formed by cells called
osteoblasts.
 Osteoclasts, large multinucleate cells,
break down old bone and are
responsibly for releasing calcium into
the blood stream.
 On Earth the process is in equilibrium.

Function of Bones on Earth
Mechanical support
 Storage of essential nutrients
 Production of blood
 Protection

Bones in Space
The amount of weight bones must
support is decreased to almost zero.
 Bones that aid in movement are no
longer subjected to the same stress.
 Calcium in bones is broken down and
released into the blood stream.
 Decrease in bone density
(osteoporosis).

Bones in Space
Bone loss begins in the first few days.
 Most severe loss occurs between the
second and fifth months in space.
 Extended stays on Mir have resulted in
losses of bone mass of as much as 20%
 Astronaut regains some bone mass after
returning to Earth, but not all of it.

Muscle loss

Astronauts need to use their muscles
very little in space.
 Muscle loss and atrophy
Fluid Shift
Body no longer
experiences the
downward pull of gravity
to distribute blood and
other body fluids.
 Headward shift.

Fluid Shift
Body senses an over abundance of fluid
in the chest.
 Body tells kidneys to get rid of excess
water.

 Astronauts do not feel thirsty
 Increase in fluid elimination

Because body has less fluid the heart
does not have to work as hard.
Sleep
Bathroom
Hygiene
Exercise
Training
NBL