claude a. piantadosi, md director, f.g hall laboratory for hyperbaric, hypobaric, and environmental...
TRANSCRIPT
Space Exploration II
Claude A. Piantadosi, MDDirector, F.G Hall Laboratory for Hyperbaric, Hypobaric, and Environmental MedicineDuke University School of Medicine
Space Exploration II
Objective “To boldly go where no one has gone
before”▪ Problem 1: Choosing a destination
▪ The Moon▪ A Lagrange point ▪ Mars▪ An Asteroid
▪ Problem 2: Getting there▪ Problem 3: Staying there▪ Problem 4: Coming home
Mankind Beyond Earth
Mankind Beyond Earth
Chesley Bonestell1888-1986
“—the painting that launched a thousand careers."
Saturn from Titan
Mankind Beyond Earth
Civilization is obliged to become spacefaring — not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive.
—Carl Sagan
Unwelcome Visitorshtt
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Unwelcome Visitors
Unwelcome Visitors• Near Earth Objects
(NEOs)• Shoemaker-Levy-
9; May 1994 Jupiter impact
• Chelyabinsk Bolide; Feb 2013 Earth atmosphere burst
• Mars cometary event; Oct 119, 2014
• First Line Planetary Defense
• A Second HomeMars: NASA/JPL; Comet Halley: Hale Observatory; Composite: Phil Plait
Unwelcome Visitors
Source: NASA NEO Office
Mankind Beyond Earth
Problems of getting there Power (chemical propulsion is not the
solution) Life support
▪ Atmosphere/temperature control that works in deep space
Microgravity Cosmic radiation
Mankind Beyond Earth
Problems of staying there Surface Technologies
▪ Power ▪ Oxygen, water, food▪ Recycling▪ Endogenous resources (ISRU-ISLE)
Radiation Microgravity
▪ Bone loss▪ Muscle loss▪ Vision loss
Isolation/confinement
Mankind Beyond Earth
Solar system destinations:
Who will pay?
Future costs borne by Individual nations, e.g. China, Russia,
USA for political capital and prestige Consortium of nations to distribute the
cost Private enterprise groups, e.g. SpaceEx
and Bigelow for commercialization Consortium of government and private
enterprise for betterment of mankind
Major life support functions
Atmosphere supply and
control
Water storage and management
Waste recovery and recycling
Temperature and humidity control
Food storage and management
Fire safety
Radiation dosimetry and
protectionMicrobe control
Plant growth
Outside contaminant
control
Life support Crew protection Resource allocation
Atmosphere revitalization
Logan mobile
SLS-1
Space Launch System (SLS-1) Heavy lift capacity is reality
▪ Lift capacity 70 metric tons▪ Final lift capacity 130 metric tons
First test launch 2017 First astronauts 2018-2020 Safe, reliable, affordable,
reusable?
SLS-1 Configurations
Obamaroid Mission
Sweet Selene
Click icon to add pictureProject Apollo is the only time in history that human beings have left the protection of the Van Allen Belts
Surface of the Moon
LCROSS Spacecraft 2009
The old NASA Soft Shoe
Surface of the Moon
Lunar Radiation
Lunar Surface Conditions
Gravity 16% (0.165) Earth Essentially no atmosphere Large daily temperature
variations (-250 to +250oF) No magnetic field
Artist's concept lunar electrostatic radiation shield
Lunar lava tube (underground)The Geologic History of the Moon (USGS Prof. Paper 1348)
GCR
SPE
CME (solar storm)
Time
Rad
iatio
n in
tens
ity Acute radiation sickness
Lava Tunnels?
Location, location, location Is there adequate
O2 trapped on the Moon for a base? Lunar soil
(regolith) is O2-rich
Recoveraable in many ways; requires 20-50 kW/ kg O2
Solar energy not an limiting, but must supply each person with ~1kg (2.2 lbs.) O2per day
Ilmenite deposits (Iron-titanium oxide FeTiO3)
Composition of the lunar regolith
What are the Moon’s resources?
Composition of the lunar regolith:
Water on the Moon?
Three sources of water 600 million metric tons (~158 billion
gallons)▪ Deep crater ice▪ Ice-soil mixture▪ Thin diffuse, but evanescent layer
New surface technologies needed to access to it
South Lunar Pole Base?
Shackleton crater (difficult access) Solar arrays on rim could provide continuous power Malapert Peak, 5-km high is 120 km away; always visible
from Earth Large IR or liquid mirror telescope in shade of crater floor
(cold trap) LMT
The Lunar Dust Problem
The Moon is covered in dirt Ultrafine spiculated
particles that penetrate to alveolar region
It settles really slowly in 0.165 g
From the NASA Lunar Science Institute
Lunar Science for Kids:• NASA wants a fully operational moon base by 2024.
• A key challenge is preparing a landing area with launch pads that protect human habitats from being “sand-blasted” by spacecraft
• “NASA has identified blast debris from takeoffs and landings to be a hazard for its planned moon outpost,”
• David Gump, of Astrobotic Technology, Inc. and researchers at Carnegie Mellon
• NASA-sponsored report says two remote-controlled droids could build a landing site for a lunar outpost in <6 months
• A safer, cheaper alternative to human construction
• Study concludes that a pair of 330-pound (150-kilogram) robots the size of riding lawn mowers could get the job done
• The bots’ would stabilize patches of loose lunar soil and erect 8.5-foot-tall (2.6-meter) walls around launch pads
• NASA needs more information about soil conditions at the lunar poles—the likeliest sites for an outpost—before they could build prototype robots
• Estimate that two bots plus the landing vehicle and pads would cost $200 to $300 million
• The robots could continue to work after the landing site is built
The Next Generation Spacesuit
Z-2 PLSS
Is Mars Accessible to People?
Mars Direct?
Robert Zubrin1996
Destination Mars
The 1998 NASA Mars Reference Mission Conjunction
mission Long stay
mission Minimum
energy mission
Pointof
no return
Mankind Beyond Earth
Mankind Beyond Earth
Solar modulation of galactic radiation
Type of radiation Electromagnetic High energy particles Low/ mid energy particles
Arrival time Light speed Minutes to hours Days
Duration of event Hours Days Days
Minimum Maximum Minimum
Radiation Flux
GCR
SCR
11-Year Solar CycleSPE
Mars in Flight Radiation
Assuming a Total Mission Dose Equivalent of 1 Sievert, a trip to Mars and back would lead to a 5-percent increase in risk for developing fatal cancer. Currently, NASA’s career limit for astronauts is 3%.
Mankind Beyond Earth
Mars in-flight radiation
Add 10 cm H2O shielding
Day
s
Age (years)
Round trip in deep space
Total mission duration
Days on surface
0
200
400
600
800
1000
20 30 40 50 60
Mankind Beyond Earth
The Case for Mars
Distance from Sun ~1.5 AUGravity 0.38 gCO2 atmosphere1% Earth (Pb 5-7 Torr)Cold
Martian sunset: Spirit at Gusev crater
Mankind Beyond Earth
Radiation environment on Martian surfaceAverages 2.5x the dose on the ISS
Dose-rem Effects
5-20 Possible late effects; chromosomal damage
20-100 Reduction in white blood cells
100-200 Mild radiation sickness within a few hours: vomiting, diarrhea, fatigue; infection
200-300 Serious radiation sickness Lethal Dose to 10-35% of the population after 30 days
300-400 Serious radiation sickness; marrow and intestine destruction; LD 50-70
400-1000 Acute illness, early death; LD 60-95
Mars Curiosity 2012
The Weather on Mars
One Way Missions?
Escape velocity ~11,178 mph (5.03 km/sec )
DESTINATION DEIMOS:
J. S. LoganGroup Manager, Human Test Support; Clinical Services Branch/SD3; NASA Johnson Space Center
A Design Reference Architecture for Initial Human Exploration of the Mars System
D. R. AdamoIndependent Astrodynamics Consultant: Houston, TX
2nd International Conference on the Exploration of Phobos and DeimosNASA Ames Research Center
14-16 March 2011
Virtues of DEIMOSThird Largest “NEO” (12.6 km mean diameter)
Less Delta-V than Moon, Phobos, Eros (escape velocity of 12.5 mph (5.6 m/s; 20 km/h)!!
Only 20,000 km from Martian surface
Just above aerosynchronous orbit
Launch window every 2.14 years
Visualize all of Mars except extreme polar regions
Mankind Beyond Earth
Solar 76 K at 1 bar
Beyond Mars—Power
Beyond Mars
Beyond Mars—Radiation
0 10 20 30 40 50 60 70 800
10
20
30
40
50
60
70
80
90
Life time cancer riskTravel time
Distance from the Sun (AU)
Mankind Beyond Earth
Spacecraft powered by a positron reactor concept for Mars Reference
Mission spacecraft NASA xenon ion propulsion drive is reliable, lightweight, and accelerates to high velocities—but very slowly
Radiation shielding by generation of an EM field is possible
“Consumable” drives
NASA Institute for Advanced Concepts
Space Exploration II
Number of Exoplanets in Milky Way? Kepler telescope searched for exoplanets
0.5-2.0 Earth radii in 1o area of sky near Cygnus and Lyrae
(100,000 stars)▪ 2,321 candidates 2012▪ >750 confirmed exoplanets ▪ Since 1996
▪ Gas giants▪ Hot-super-Earths in fast orbits▪ Ice giants▪ Smallest radius 1.9 earth
Light Speed Ship Design
Habitable Zone
Space Exploration II
“Nearby” Stars
Space Exploration II
Click icon to add pictureAlpha Centauri is a binary G star system 4.3 light years away
Assume the Sun is the size of a quarter
Earth is the size of a period
Earth to Sun is 107 quarters side- by-sideSun to Alpha Centauri is >30 million quarters (Durham to Philadelphia)
Kepler 22b (600 light years away)
Earth Masses36-124
Kepler 186f System (500 light years)
Conclusions?