National Aeronautics and Space Administration
Human Research Program
Knowledge & Technological Solutions for Safe, Productive Human Exploration
Goals of HRP
• Develop capabilities,
countermeasures, and technologies
in support of human space
exploration
• Define and improve human
spaceflight medical, environmental,
and human factors standards;
• Ensure effective human-system
integration across exploration
systems
National Aeronautics and Space Administration
Integrated Human Systems
The human body is a highly integrated set
of systems that work together to allow
astronauts to perform mission objectives.
Two physiologic systems that need to
always work in harmony are bone and
muscle. These two systems are dependent
on the heart to circulate blood and the
central nervous system for balance and
integrated motion.
All of these systems are enhanced or
effectively stressed by the countermeasure
known as exercise. They also require a well
balanced diet to provide all necessary
nutrients for proper function.
National Aeronautics and Space Administration
Bone Physiology & Risk Management
Context To Exploration Missions
Normal Vertebral Bone
Prolonged exposure to reduced gravity
environments can cause bone loss,
increased loss of bone minerals,
increased chances for renal stones and
is a factor in possible post mission bone
fractures.
Background and Evidence
• On Earth, postmenopausal women who are untreated for
bone loss can lose 1-1.5 percent of hip bone mass in one
year while an astronaut can lose the same amount in a
single month.
• Recovery of reduced gravity induced bone loss is delayed
in the post-flight period.
• Calcium from bone atrophy can cause renal stones.
• In the absence of loading to the spine, that is, no forces
from gravity or back muscles, intervertebral discs can swell
and the spine can become misaligned
• Space-flight induced changes may predispose the discs
to post-flight injuries
Thinning Bone
National Aeronautics and Space Administration
Muscle Physiology and Risk Management
Context To Exploration Missions
Exposure to reduced gravity causes muscle fibers
to shrink leaving astronauts weaker and less
coordinated.
Background and Evidence
• Exposure to long-term reduced gravity causes reduction
in muscle mass and strength, especially in the lower
extremities (legs)
• In flight durations of less than 14 days on the
Shuttle, astronauts experienced a up to 1/3 reduction
in muscle fiber size
• Space flight and ground-based flight analog research
indicates that muscle size and function could be
reduced as much as 20-40% during long duration
exploration missions if effective countermeasures
are not in place.
• Reduced coordination due to space flight-associated
sensorimotor impairment will create an added difficulty in
completing mission tasks with weakened muscles.
• Crew must maintain strength for mission objectives and
emergency egress
• Astronauts primarily use exercise during long-duration
missions onboard ISS to mitigate these alterations
National Aeronautics and Space Administration
Exercise Countermeasures
Context to Exploration Missions
Proper exercise is important to mission
success, as it helps astronauts to counter the
de-conditioning effects of reduced gravity.
Background and Evidence
• Loss of muscle = Loss of Strength
• Astronauts have been shown to lose 1/4 of
their aerobic capacity after just a two week
shuttle mission.
• Astronauts spend up to 2 hours a day on
exercise to help maintain bone and
muscle.
• The new Advanced Resistance Exercise
Device (ARED):
• Double the resistive capacity from the
IRED capability of 300 lbs to 600 lbs.
• ARED allows NASA to use ISS as a
spaceflight platform to learn what
loading profile is required to protect
muscle and bone during exploration.
National Aeronautics and Space Administration
Cardiovascular Risk Management
Context To Exploration Missions
Reduced cardiac function could jeopardize
crew health and performance, especially after prolonged
missions. Therefore it is necessary to determine if these
risks can be managed through exercise and astronaut
selection.
Background & Evidence
• Cardiac arrhythmias have been observed during space
flight, though it is not clear whether space flight itself is
the cause.
• Decreases in cardiovascular size and function may
reduce the ability to deliver oxygen to muscles, which
decreases the ability to perform physically demanding
tasks.
• Soon after launch, body fluid including blood moves
from the legs to the head and upper body. As a natural
reaction to this, the total amount of blood in the body is
decreased. When the astronaut returns from zero
gravity to gravity or perhaps even partial gravity the
decreased amount of blood in the body, (similar to
dehydration) may contribute to temporarily low blood
pressure.
• If the blood pressure is low enough, some astronauts
may faint after space flights when their blood pressure
falls due to a small, relatively empty heart.
National Aeronautics and Space Administration
Space Nutrition Risk Management
Context To Exploration Missions
Nutrients are required for the structure and function of
every cell and every system in the human body. Defining
the nutrient requirements for spaceflight and ensuring
provision and intake of those nutrients are primary issues
for crew health and mission success.
Background & Evidence
• Food intake is often lower than the estimated need
• Body mass losses of 1% - 5% of preflight body mass have
been a common finding after space flight.
• Bone and muscle loss during flight are significant.
Nutrition may provide a means to mitigate these changes.
• Food and nutrition are different issues. One historical
example of this difference: Exploring sailors who died of
scurvy had food, but they were missing the essential
nutrient Vitamin C
National Aeronautics
and Space
Administration
National
Aeronautics
and Space
Administration
Space Human Factors & Habitability
Context to Exploration Missions
The purpose behind human centered design
is to reduce the probability of injury of
crewmembers and to reduce or mitigate risks
to human performance or achieving mission
objectives.
Background and Evidence
• Human Centered Design focuses upon the
human-machine interface, spacecraft
architecture and topology, the environment,
stowage, human computer interaction,
hardware and tool designs.
• Without focusing on the human as the
central component to the human-machine
system, risks develop that can prove
catastrophic
• As systems become more complex and
compact, human centered design becomes
essential
• A safe, nutritious, and acceptable food
system is required, while still balancing
appropriate vehicle resources
• A safe, healthy environment is needed prolonged exposure to respirable lunar dust
could be detrimental to human health
National Aeronautics and Space Administration
Behavioral Health and Performance Risk Management
Context To Exploration Missions
Sleep loss, fatigue, poor team cohesion, and psychological
problems can jeopardize health and performance during
exploration missions. Efforts are needed to ensure optimal
conditions for sleep quality and circadian regulation;
psychological support for individuals and teams, specific to the
new mission environment; and unobtrusive monitoring for
early detection and intervention.
Background and Evidence
• Astronauts, on average, sleep less than six hours per day,
and even less prior to critical mission ops.
• Earth-based studies reveal that sleep of less than six hours
per day can result in cumulative performance deficits.
• While incidences of anxiety disturbances have occurred, no
behavioral emergencies, defined as agitation, psychosis, or
suicidal behavior, have been reported during spaceflight.
• Unquestionably, as mission duration increases, so does the
likelihood of the occurrence of a behavioral or psychiatric
condition.
• Individual factors (personality and general mental ability) can
predict quality of performance in a teamwork setting; team
composition is strongly related to mission success
• Interpersonal compatibility, team training together, and
leadership competencies all promote optimal team
performance
National Aeronautics and Space Administration
Sensorimotor Risk Management
Context To Exploration Missions
Sensorimotor disturbances occur during
adaptation to spaceflight and during
readaptation to gravity on planetary surfaces.
These changes can impact control of vehicles
and impair functional performance during the
acute phase of adaptation to novel
gravitational environments.
Background & Evidence
• Research has demonstrated changes
in manual control, visual performance,
spatial orientation and gait control.
• Greatest changes occur during period
immediately following gravity transition.
• Post flight disturbances increase with
length of flight.
National Aeronautics and Space Administration
Immune System Physiology Risk Management
Context To Exploration Missions
Spaceflight-associated immune dysregulation persists
during exploration flights in conjunction with other
factors such as high-energy radiation. It is unclear if
this leads to an increased susceptibility to cancer,
infectious disease, allergy/hypersensitivity and
autoimmunity.
Background & Evidence
• Human immune function is altered in flight and post
flight. The significance of the dysregulation during
long duration flight is unknown.
• Reactivation of latent herpes viruses has
been observed repeatedly during short
duration flight
Pre-Flight
Landing Day (R+0)
• Depressed cell directed immunity has been
observed during long duration flight
• In-flight culture of immune cells has clearly
demonstrated altered functional
characteristics during space flight.
• Within two weeks after landing, immune
response returns to normal.
Image at right: altered cell cytokine production; ISS crewmember.
National Aeronautics and Space Administration
Radiation Risks & Countermeasures
Context To Exploration Missions
Space radiation may place the crew at significant risk for radiation
sickness, and increased lifetime risk for cancer, central nervous system
effects, and degenerative diseases. Beyond Low Earth Orbit, the
protection of the Earth's atmosphere and magnetosphere are no longer
available. We will need to learn more to be certain that acceptable risks
are not exceeded and to understand shielding and biological
countermeasures required to protect the crew.
Background & Evidence
• Human epidemiology studies of exposure to various doses of
X-rays or gamma-rays provide strong evidence that cancer and
degenerative diseases are to be expected from exposures to
galactic cosmic rays (GCR) or solar particle events (SPE)
• Astronauts are exposed to ionizing radiation with effective doses
in the range from 50 to 2000 mSv (milli-Sievert).
• Although the type of radiation is different, 1 mSv is equivalent to
about 3 chest x-rays.
• Differences in biological damage of heavy nuclei in space with xrays, limits Earth-based data on health effects for space
applications
• Shielding is not effective against GCR (penetrating protons and
heavy nuclei), but it can be against SPEs (largely medium
energy protons), optimization is needed to reduce weight of
shielding.
•
Animal models must be applied or developed to estimate cancer,
and other risks.
•
We must be able to predict Individual astronaut’s radiation
sensitivity and resistance.
National Aeronautics and Space Administration
EVA Suit Risk Management
Context to Exploration Missions
Missions to the Moon may include up to 24 hours of EVA per
astronaut per week. Mission success depends on designing
EVA systems and protocols that maximize human
performance and efficiency while minimizing health and
safety risks for crewmembers.
Background and Evidence
•
Design variables: suit pressure, suit weight, location of suit
center of gravity, joint ranges of motion, and biomedical
monitoring
•
The implications of mission architecture on crew health and
safety, productivity, and efficiency are potentially enormous.
Mission Architecture must consider:
• Decompression sickness or other medical treatment
• Solar Particle Element (SPE) protection
• The number of in-suit EVA hours to achieve the same or
greater science/exploration
• EVA risk for crewmembers
• The number of cycles on the EVA suits
Orange suit is worn during launch & landing.
The white suit is for Moonwalks and lunar
exploration and is self contained.
National Aeronautics and Space Administration
Lunar Dust Exposure
Context To Exploration Missions
Mineral dust with similar properties to lunar dust are
known to be toxic as well as being an irritant. Health
standards are needed based on the estimated
exposure risks in order to design lunar habitats. HRP
research will produce a health standard for inhalation
exposure to lunar dust particles at a level that is safe,
but not overly conservative. In addition, provide an
understanding of the risks for eye and skin irritation.
Background and Evidence
• Solar wind causes protons and UV radiation to bombard
the lunar surface activating exposed dust. When this dust
comes in contact with sensitive areas like the eyes or
lungs, a chemical reaction takes place, which can cause
irritation.
• Large surface area and iron content of dust may contribute
to it being moderately toxic.
• Lunar dust has electrostatic charge, which contributes to
it’s ability to cling to everything, as seen in these Apollo
mission pictures of Gene Cernan covered in lunar dust.
• The lunar dust health standards will be a key requirement
affecting:
•
removal of dust from the suit
•
Airlocks that minimize entry of dust into the habitat
and suit,
•
monitoring dust concentrations in habitat
•
methods for rapid deactivation of dust once it
enters the habitat.
Above, Magnified lunar dust particles
Below, Gene Cernan Apollo 17 Mission, covered in lunar dust
National Aeronautics and Space Administration
Exploration Medical Capability
Context To Exploration Missions
Mission architecture limits the amount of equipment and procedures
that will be available to treat medical problems. Resource allocation
and technology development must be performed to ensure that the
limited mass, volume, power, and crew training time be efficiently
utilized to provide the broadest possible treatment capability.
Background & Evidence
Challenges:
• Resource constraints (mass, power)
• Lack of trained medical professionals
• Limited pre-flight crew training time
• Limited shelf life of medical supplies
• Encountering ailments unique to Space environment
Possible Solutions:
Evaluation of device for
producing medical
water for injection (IV)
from a space vehicle’s
potable water supply.
Lightweight Trauma
Module jointly
developed by NASA
and DoD.
• Additional emphasis on telemedicine and remote guidance
for medical procedures
• Development of computerized guides to facilitate care
delivery and provide medical decision support
• Development of an Integrated Medical Model (IMM) to help
anticipate likely medical conditions and the resources
required to treat the conditions.
• Lab-on -a-Chip device: a drop of blood or urine is placed on
a small microtest chip. Test results quantifying the health of
major organ systems are generally available in a few
minutes. Requires very little space.
Lab-on-aChip
Medical training
procedures during a
C9 flight
National Aeronautics and Space Administration
Human Exploration Continues
Context To Exploration Missions
As we begin the journey into the 21st
Century we reflect on where we have
been, continue to learn about
exploration here on Earth and
envision tomorrows’ journey beyond.
“We have taken to the Moon the wealth
of this nation, the vision of its political
leaders, the intelligence of its
scientists, the dedication of its
engineers, the careful craftsmanship of
its workers, and the enthusiastic support
of its people. We have brought back
rocks, and I think it is a fair trade . .
. Man has always gone where he has
been able to go. It's that simple. He will
continue pushing back his frontier, no
matter how far it may carry him from his
homeland.”
- Col. Michael Collins
Small Pressurized Rover concept
Astronaut Harrison Schmitt uses
scoop to retrieve lunar samples
during EVA
National Aeronautics and Space Administration
Closing Slide with NASA Logo
National Aeronautics and Space Administration
Replacing Old Bone with New Bone Material (Bone Remodeling)
Back
Ott, S. (2008) Osteoporosis and Bone Physiology. Retrieved November 19, 2008,
from http://courses.washington.edu/bonephys/ophome.html
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