advancing torpor inducing transfer habitats for … · advancing torpor inducing transfer habitats...
Post on 14-Aug-2018
220 Views
Preview:
TRANSCRIPT
ADVANCING TORPOR INDUCING TRANSFERHABITATS FOR HUMAN STASIS TO MARS2016 NASA NIAC Symposium24 August 2016 | Raleigh, NC John E. Bradford, PhD.
NIAC FellowPresident and COO
SpaceWorks Enterprises, Inc.
Douglas Talk, M.D., M.P.H.Medical Liaison
Mark SchafferSenior Engineer
SpaceWorks Enterprises, Inc.
Atlanta, GA | www.sei.aero | info@sei.aero
CONCEPT OVERVIEW
Place a Mars-bound crew in inactive, low-metabolic Torporstate for mission transit phases by expanding current medical
practices in Therapeutic Hypothermia to support ProlongedHypothermic Stasis and Metabolic Suppression.
3
CONCEPT
4
• Significant decrease in mission consumables due to inactive crew and reduced metabolic rates
• Large reductions in pressurized volume required for habitation and living quarters
• Eliminates many ancillary crew accommodations (food galley, eating supplies, cooking, exercise equip., entertainment, etc.)
• Minimize psychological and social challenges for crew
• Potentially solves or mitigates a number of health issues with long-duration spaceflight
RATIONALE
5
Effect of Body Temperature (°C) Evaporative Cooling Systems
THERMAL MANAGEMENT
Threshold formedical complications
Image Credit: Benechill
Image Credit: Advanced Cooling Technologies
Normothermia
Shiving starts
MildHypothermia
ModerateHypothermia
DeepHypothermia
ProfoundHypothermia
38°36°34°32°30°28°26°24°22°20°18°16°14°
Standard medical practice for TherapeuticHypothermia (TH)
NUTRITION AND HYDRATION
6
0
100
200
300
400
500
600
700
800
Fully Active Resting Torpor (likely) Torpor (potential)
Mas
s (g/
pers
on/d
ay)
Lipids
Amino Acids
Dextrose
Total Parenteral Nutrition (TPN) is the feeding of a person intravenouslywith a mixture of lipids, amino acids, dextrose, electrolytes, vitamins, and trace elements; all of the essential nutrients for human body
– Delivered via a tunneled central venous catheter or a peripherally inserted central catheter (PICC)
– Bypasses the usual process of eating and digestion
Pinnacle System ™
7
IMPLEMENTATION IN SPACE
PREVIOUS STUDY FINDINGS
KEY CHALLENGES FROM PHASE I EFFORT• Maximizing stasis period
– Common practice is 2-3 days, more cases at 4-5 days, with some very limited cases at 14-days
• Mitigating known complications of TPN and hypothermia– thromboembolism, infection, fatty liver disease, etc.
• Developing procedures for addressing medical issues that could occur during transit with inactive crew– automated vs. human intervention
• Addressing slow wake times that are currently required during warming
• Uncertainty in effects of prolonged torpor on crew mental faculties
9
Total Pressurized Volume : 500 m3
Habitable Volume : 350 m3
Mass with Consumables : 40.6 t
10
Total Pressurized Volume : 75 m3
Habitable Volume : 8 m3
Mass with Consumables : 12.7 t
9.0 m
8.2 m
5.0 m
4.3 m
HABITAT MASS REDUCTION OF 50-70%
HABITAT SIZE REDUCTION
100-PERSON MARS TRANSFER VEHICLE
11
Crew HabitatModule
4 active crew
Power ModuleRadiation Shield
Power Module NuclearReactor Assembly
Torpor-Enabled PassengerHabitat Modules
48 passengers each
Cupola Module Access Node Modules
Power ModuleRadiator Assembly
Element Mass Power
Crew Habitat Module 23 t 27 kWe
Torpor Passenger Habitat Module 1 71 t 101 kWe
Torpor Passenger Habitat Module 2 71 t 101 kWe
Access Nodes & Cupola 11 t 3 kWe
Power Generation Module 19 t 15 kWe
Total 196 t 297 kWe*
PHASE II PLANS
13
Doug Talk, M.D., M.P.H.Medical Team Lead
Naval Air Station Lemoore, CADepartmental Director of Surgical Services
Kelly Drew, Ph.D.Neuroscientist, Professor
Be Cool Pharmaceutics (BCP), LLC.Professor, University of Alaska FairbanksDepartment of Chemistry and Biochemistry, Institute ofArctic Biology (IAB)
Alejandro Rabinstein, M.D.Professor of Clinical Neurology
Mayo ClinicMedical Director of Neuroscience Intensive Care Unit(ICU)
Matthew Kumar, M.D.Asst. Professor of Anesthesiology
Mayo Clinic Health System Albert Lea/AustinChair (Department of Anesthesiology)
Leroy Chiao, Ph.D.Astronaut
ISS Expedition 10 Commander, STS-65/72/92 MissionsDoctorate in Chemical Engineering
MEDICAL TEAM
Mars Mission Habitat Designs• Habitat Internal Thermal Environment
Analysis
• Radiation Shielding Assessment
• Crew Concept of Operations
• Torpor Habitat Design Refinement
FOCUS AREAS
14
Medical Assessments and Evaluations• Nutrition and Intravenous Support
• Metabolic Suppression Approaches
• TH Physiological Impacts
• Evaluation of Prolonged Hypothermiain Non-Hibernating Mammals
Technology Roadmap Development• Identification of Key Challenges
• Maturation Costs
• Near-Term and Long-Term Development Roadmaps
Extensibility Beyond Mars• Martian Moons
• Main Belt Asteroids
• Jupiter and Saturn Systems
A1AR Research Studies• Attempt to mimic mechanisms occurring when entering hibernation• Activation of adenosine A1 receptor with CHA agonist and 8-SPT appears
to attenuate thermogenesis and suppress shivering• demonstrated in arctic ground squirrels and rats to date
15
Jinka, Combs, and Drew, ACS 2015
PROMISING MEDICAL RESEARCH
16
ARTIFICIAL-G INDUCING HABITAT DESIGNS
Analogy Earth Gs Rotation
Moon 0.16 7 rpm
Mars 0.38 12 rpm
Earth 1.00 18 rpm
17
MarsMartian Moons Vesta Ceres Jovian
Moons
Propulsive ΔV 10 km/s 16 km/s 20 km/s 45 km/s
Mission Duration 2-3 years 2-3 years 2-3 years 5-7 years
Opportunity Frequency 2.1 years 1.4 years 1.3 years 1.1 years
Max Distance from Earth 2.7 AU 3.6 AU 4.0 AU 6.5 AU
MARS AND BEYOND
CONCLUDING REMARKS
18
19
FINAL REMARKS
• “Mild hypothermia” continues to appear as the most promising approach toward enabling human stasis (and Mars missions!)– Goal is stasis for full duration of transit to and from Mars– Contingency design and protocol exists if only able to achieve periods of a
few weeks
• Prolonged hypothermic stasis combined with metabolic suppression may provide a number of unique benefits and solve a variety of medical challenges for space travel
• Will continue to evaluate the architecture-level impacts of this technology to various envisioned future exploration missions and destinations
SPACEWORKS ENTERPRISES, INC. (SEI) | www.sei.aero | info@sei.aero1040 Crown Pointe Parkway, Suite 950 | Atlanta, GA 30338 USA | +1-770-379-8000
Engineering Today, Enabling Tomorrow
BACKUP
22
ARTIFICIALLY INDUCING HIBERNATIONThree approaches possible for humans:
1. Temperature-based– Lowering of core temperature through either invasive cooling (infusing
cooled IV fluids), conductive cooling (through the use of gel pads placed on the body or with evaporative gases in the nasal and oral cavity)
2. Chemical/Drug-based– In 2011, Scientists at Univ. Alaska successfully induced hibernation by
activating adenosine receptors in arctic ground squirrels– Inhaled Hydrogen Sulfide (H2S) shown to induce deep hibernation state
within mice by reducing cell demand for oxygen
3. Brain Synaptic-based– Current research shows significant decreases in the number of dendritic
spines along the whole passage of apical dendrites in hibernating creatures
26
HYPOTHERMIA THERAPY MILESTONES
27
Year Description
1945 First medical articles concerning use of hypothermia published
1955 Division of Medical Sciences, NRC symposium on the Physiology of Induced Hypothermia, sponsored by U.S. Army, Navy, and Air Force
1980 Animal studies prove that mild hypothermia acts as a general neuro-protectant following a blockage of blood flow to the brain
2002 Two landmark human studies published simultaneously by the New England Journal of Medicine
2003 American Heart Association endorses the use of TH following cardiac arrest
2005 Protocols for use of TH for prenatal infants established
2009 RhinoChill® IntraNasal cooling system enters clinical trials
POTENTIAL MEDICAL CHALLENGES
29
Issue Initiator Solution/Comment
TORPOR-SPECIFICThromboembolism(Blood Clotting)
Prolonged sleep status and indwelling IVs
Periodic heparin flushes to dissolve clots, Clotting is generally reduced in TH state, Minimize IV access
BleedingDecrease in coagulation factor activity
Not a significant concern outside of traumaMay decrease risk of thromboembolism
InfectionTemperature reduction in white blood cell activity
Minimize IV access, improved sterile techniques, use of tunneled catheters and antibiotic-infused catheters
Electrolyte ImbalancesDecreased cellular metabolism
Close monitoring and IV stabilization with TPN
Fatty Liver and Liver Failure Long term TPN usage Can alternate source of lipids to reduce risk
Other Complications (hypo/hyper glycemia, bile stasis, etc.)
TPN and reduced metabolic rate
Augment TPN with insulin, exogenous CCK, etc.Avoid abrupt termination of TPN
GENERAL CREWED SPACEFLIGHTBone Demineralization and Density Loss
Prolonged zero-G environment
Pharmaceuticals (e.g. bisphosphonates)Artificially-induced gravity
Muscle Atrophy DisuseAutomated physical therapy toolsNeuromuscular electrical stimulation (NMES)
top related