Integrated Human Systems for Safe Space Exploration

1. Human Research ProgramKnowledge & 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

2. 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.

3. Bone Physiology & Risk Management Normal Vertebral Bone Context To Exploration Missions 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

4. 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

5. 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.

6. 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.

7. 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

8. National Aeronautics and Space Administration Space Human Factors & Habitability Context toExploration 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

9. 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

10. 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.

11. Landing Day (R+0) Pre-Flight 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 • 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.

12. 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 x-rays, 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.

13. 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.

14. 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

15. 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: • 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. 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. Lab-on-a-Chip Medical training procedures during a C9 flight

16. 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 Astronaut Harrison Schmitt uses scoop to retrieve lunar samples during EVA Small Pressurized Rover concept

17. Closing Slide with NASA Logo

18. Replacing Old Bone with New Bone Material (Bone Remodeling) Ott, S. (2008) Osteoporosis and Bone Physiology. Retrieved November 19, 2008, fromhttp://courses.washington.edu/bonephys/ophome.html Back Next