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

p:/

/ww

w.p

urd

ue.e

du

/im

pact

eart

h

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

James.s.logan@nasa.gov

A Design Reference Architecture for Initial Human Exploration of the Mars System

D. R. AdamoIndependent Astrodynamics Consultant: Houston, TX

Adamod@earthlink.net

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?