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1、Introduction to Space Life Sciences,Gilles Clment,Ph.D,CNRS Cerveau et Cognition LaboratoryToulouse,France,Kluwer Academic Publishers Copyright 2003 All rights reserved,Fundamentals of Space Medicine Chapter 1,Key Concepts,Space Life Sciences:What is it?Where we areThe historical context of human sp
2、aceflight How we got thereThe importance of continuing research before long-duration exploration missions can be safely undertaken Where do we go from here,Space Life SciencesWhat is it,Life Sciences are specifically devoted to the working of the living world(from bacteria and plants to humans)On Ea
3、rth,all living organisms have developed as a result of constant exposure to 1-g gravitySpace Life Sciences open a door to understanding ourselves,our evolution,the working of our world without the constraining barrier of gravityBeside microgravity,during space flight living organisms are also affect
4、ed by ionizing radiation,isolation,confinement,changes in circadian rhythms(24-hr day/night cycle),etc.Objectives of space life sciences:Enhance fundamental knowledge in cell biology and human physiologyProtect the health of astronautsDevelop advanced technology and applications for space and ground
5、-based research,Justification for Human Spaceflight,Robotics versus Human crews=Apples versus OrangesHuman Pros:intelligent operators,efficient end-effectorsHuman Cons:expensive,complexity of habitable environmentHuman spaceflight critics often discount the value of Life Sciences on the“Discovery Le
6、dger(Big Book)”often due to following fundamentals differences:Physical Sciences:more concrete discoveries in relatively unexplored sphereLife Sciences:an inherently inexact science;context of background physiological variability;requirement for repeated measurements,Photo NASA,Space Medicine versus
7、 Space Physiology,Space MedicineTo solve medical problems encountered in spaceflightIncludes some adaptive changes(e.g.,space motion sickness),environmental exposures,etc.Includes also some non-pathologic changes which become maladaptive on return to Earth(e.g.,bone loss)Outlook is operational,views
8、 problems/peculiarities from standpoint of mission impactSpace PhysiologyTo characterize response to space,especially 0-GNecessary knowledge base for aboveOutlook is investigational,views problems/peculiarities from standpoint of scientific return,Where we are(as of 1st July 03),Photo CNES,Total num
9、ber of persons who have flown in space:433(41)Cumulative spaceflight time:72 years(26.410 days)Mean spaceflight duration:28 daysCumulative spaceflight duration by individual:Polyakov(679 days;2 flights)Avdeyev(748 days;3 flights)Re-adaptation to Earth gravity stated to be 90%complete after 6 years V
10、alery Polyakov(during a science conference)How did we get there?,22 months,25 months,1783:Two French gentlemen ride a hot-air(Montgolfier)balloon,Major Space Life Sciences Events,1951:First successful(non-orbital)flight of a sounding rocket with a monkey and 11 mice(previous attempts since 1948 were
11、 not successful),1957:Dog Laika first living creature into orbit(died after a few days)followed by monkeys,Photo CNES,1959:Selection of 7 American astronauts,Major Space Life Sciences Events,1960:Selection of 11 Soviet cosmonauts,Photo NASA,Photo RSA,1965:First space walk(Extra-Vehicular Activity),1
12、961:First human to orbit the Earth(Y.Gagarin)1963:First woman(V.Tereshkova)in spacesecond Russian woman(S.Savitskaya)did not fly until 1982,Major Space Life Sciences Events,1965-66:Longest stay in space is 14 days(Gemini 7)first observations on human body adaptation artificial gravity first tested(G
13、emini 11),Major Space Life Sciences Events,70s:Salyut,Skylab start of detailed SLS investigations,1981:First space vehicle piloted during return(Shuttle),Photos NASA,2000:First expedition crew on board ISS,1994:Longest stay in space is 14 months(MIR),Human Spaceflight Experience,Adapted from Reschke
14、 and Sawin(2003),Human Spaceflight Experiencegreater than 30 days,Humans in Space,First space missions were to demonstrate that humans could survive a journey into spaceSome people doubted whether humans could endure the g forces of launch and re-entry,or swallow,or sleep in the absence of gravitySo
15、me predicted that the bowels would not work without gravity,the heart might cavitate like a pump,or become so weakened as to prohibit return to Earth,How long can humans live in space,and how effectively can they work in space are still open questionsLiving and working is far different from merely s
16、urvivingAfter extended stays in space,can people return safely to Earth and lead normal,healthy lives?Such questions are much more difficult than questions of survival because they require sophisticated scientific experimentation,Movie:13_impossi,Surviving the Odyssey,What Really Occurs,No up or dow
17、n disorientation,nausea,Fluids shift towards head puffy face,sinus congestion,headache,changes in smell and taste,Antigravity postural(extensor)muscles not used new locomotion pattern,chicken legs,muscle strength and endurance decrease,Photos NASA,What Really Occurs,Bone density decreases by 1-3%per
18、 month,No up or down disorientation,nauseaFluids shift towards head puffy face,sinus congestion,headache,changes in smell and tasteAntigravity postural(extensor)muscles not used new locomotion pattern,chicken legs,muscle strength and endurance decrease,Fluids volume decreases changes in heart volume
19、,heart rate,and blood pressure,breathing difficult(less red blood cells),What Really Occurs,Intervertebrate disks less compressed height increases,back pain,Sleep disorders,No up or down disorientation,nauseaFluids shift towards head puffy face,sinus congestion,headache,changes in smell and tasteAnt
20、igravity postural(extensor)muscles not used new locomotion pattern,chicken legs,muscle strength and endurance decreaseFluids volume decreases changes in heart rate and blood pressure,breathing difficult(less red blood cells)Bone loss,Adapted from Lujan and White(1994),Photo NASA,No up or down disori
21、entation,nauseaFluids shift towards head puffy face,sinus congestion,headache,changes in smell and tasteAntigravity postural(extensor)muscles not used new locomotion pattern,chicken legs,muscle strength and endurance decreaseFluids volume decreases changes in heart rate and blood pressure,breathing
22、difficult(less red blood cells)Bone lossIntervertebrate disks less compressed height increases,back painSleep disorders,What Really Occurs,Psychological troubles,Sharper vision,but light flashes(radiation),Photo NASA,Photo NASA,Issues for Human Missions,Preflight:Astronaut selection,crew selection,m
23、edical trainingInflight:Acceleration,vibration,noise during launch and landing,Movie:19_launch,Preflight:Astronaut selection;crew selection;medical trainingInflight:Acceleration;vibration;noise during launch and landing,Psycho-sociological issues(support)Environmental issues:toxic substances,pressur
24、e changesExtra-Vehicular activity(EVA):strain on muscles and bones,decompression-related disorders,Physiological adaptation:heart(dys-rhythmias)and blood vessels,muscles(strength),bones(fractures,renal stones),nervous system,immune system(infection),Radiation(sterility,cancer),Crew medical officer:d
25、iagnosis,treatment(surgery),Emergency return,Issues for Human Missions,Issues for Human Missions,Postflight:Piloting1-g feels like 4-g Emergency egressStanding:orthostatic intoleranceWalking:postural instabilityMotion sickness(Mal de Dbarquement)Muscle and bone weaknessDecreased exercise capacityRet
26、urn to flight status,Photo NASA,Countermeasures,2 daily 1-hour sessions of exercise:Treadmill with axial loadingCycle ergometerResistive exerciseTraction on“bungee cords”Low Body Negative PressureFluid loading before re-entry,Photos NASA,Human Mars Mission,Challenges for a Mars Mission,Crew selectio
27、nOnboard medical officerRadiation doseBone lossAdvanced Life Support Systems,Spaceflight Life Support,Human requirementsHygiene,sanitation Nutrition(adequate,appealing)Rest(avoid chronic fatigue)Exercise(fitness,recreation,motivation)Human performance(psycho-social,workload,circadian factors)Life su
28、pport systemsAtmosphere,temperature,lighting,noiseFood,wasteFrom physico-chemical(recycled)to bioregenerative(ecologically closed)Biosphere 2Mir GreenhouseBio-Plex,Photo NASA,Photo ESA,Greenhouse in Space,Critical questions to be addressed:How far can we reduce reliance on expendables?How well do bi
29、ological and physico-chemical life support technologies work together over long periods of time?Is a“steady state”condition ever achieved with biological systems?How do various contaminants accumulate and what are the long-term cleanliness issues?,Photo NASA,Challenges,Short-duration spaceflights pr
30、esumably OK for touristsFor long-duration missions,the MIR experience indicates that current inflight countermeasures are not optimalUsing the current countermeasures methods,humans would not be operational after landing on Mars Artificial gravity probably the most efficient countermeasure,Photo CNE
31、S,Movie:27_cosmonaut,Artificial Gravity,Principle of centrifugation,For interplanetary travel the design is most likely to be a short-arm bined with muscular exercise,Criteria for comfort(less motion sickness with lower angular velocity;low velocity means large radius),Recommended zone for effective
32、 human performance in rotating space systems,Photo NASA,Movie:28_centrifuge,Movie:28_hyperg,Future Research,Changes seen at cellular level.However,too much publicity on biochemical factories in spacePlants in space.Life support systems:how to move from physico-chemical to closed ecological life supp
33、ort systemsHuman Mars mission.Probably the longest period away from Earth to date;also probably the longest exposure to hypogravity(1/3 g)environment to date,Think about development of insects,amphibians,mammals after several generations without perceived gravity,Space Life Sciences research is on h
34、old now,ISS should be ideal for study of fundamental biological processesnew science:gravitational physiology;no Nobel prize yet,but given prizes have been challenged,Document NASDA,Photo NASA,Movie:29_frog,Benefits of SLS Research,BiologyImprove overall health of people of all agesImprove crop yiel
35、ds using less nutrients and smaller surfaceAdvance understanding of cell behaviorBiotechnologyProvide information to design a new class of drugs to target specific proteins and cure specific diseasesCulture tissue for use in cancer research/surgery and bone and cartilage injuriesBiomedical ResearchE
36、nhance medical understanding of the role of force on bone in disease processes including osteoporosis(bone loss)Advance fundamental understanding of the brain and nervous system and help develop new methods to prevent and treat various neurological disorders(e.g.,multiple sclerosis)Develop methods t
37、o keep humans healthy in low-gravity environments for extended time periodsEducationUse science on orbit to encourage and strengthen science education on Earth,Additional Reading,Clment G(2003)Fundamentals of Space Medicine.Dordrecht:Kluwer Academic PublishersMullane MR(1997)Do Your Ears Pop in Spac
38、e?New York,NY:John Wiley&SonsOser H,Battrick B(1989)Life Sciences Research in Space.ESA SP-1105.Paris,France:ESA Publication DivisionWassersug RJ(2001)Vertebrate Biology in Microgravity.American Scientist 89:46-53Wolfe T(1979)The Right Stuff.New York,NY:Farra,Straus&GirouxA Strategy for Research in
39、Space Biology and Medicine in the New Century.National Research Council.Washington,DC:National Academy Press,1998National Geographic.The Body in Space.January 2001 issueFifth Symposium on the Role of the Vestibular Organs in Space Exploration.NASA SP-314,1973http:/www.nsbri.org/HumanPhysSpace/index.htmlhttp:/weboflife.arc.nasa.gov/http:/lifesci.arc.nasa.gov/,
