Space: From Foray to Habitation

A Plan for the Human Habitation of the Solar System

Prof. David Hyland

Mech Aero – 2014

Hilton Philadelphia Airport Hotel

September 8 -10, 2014

The Question

Can humanity spread throughout the solar system beyond the Earth, using only technologies that already exist or are presently in an advanced stage of development?

(No warp drives, matter transmit beams, dynamic Casimir thrusters or artificial gravity that does not use rotation, etc., etc.)

First step: Escaping the gravity well (cheaply)

Attempt no “all purpose vehicle”. Separate functions, simplify components, build infrastructure Establish a “garage” of reusable reentry vehicles in LEO Use ELVs to transport both humans and cargo to LEO.

Expectation is that human explorers will subscribe to an extended stay.

Design upper stages to be disassembled into standardized components that are used to build infrastructure and habitations

Bare-bones launch vehicle to orbit; transfer to space habitat; remain for indefinite mission period; transfer to reentry vehicle: return to earth

Bootstrapping to the Stars

At all stages of development, use bootstrapping to finance activities With minimum initial investment, start selling

products (on Earth) based on dual use technologies As revenue increases, set aside earnings for R&D for

the space application Avoidance of big investors permits the enterprise to

maintain its focus on the ultimate goal of human space habitation

Progress step-by-step, paying your way as you go

“Habitation Technology” (HT)

HT = An integrated and portable system of technologies that enable a small group of humans to generate their consumables, mine local resources, and fabricate and repair their own tools. Energy extraction and power generation Compact, high yield agriculture Waste processing and recycling Atmosphere maintenance and recycling Water recycling Metallurgical exploration, extraction, processing and recycling Rapid fabrication technology Autonomous system control software

“Habitation Technology” (HT) Bootstrapping

Waste processing and recycling

Compact, high yield agriculture

In situ energy extraction/power generation

Space Habitation

Terrestrial Application

Aggregate R&D

First Step in Sustained Human Presence

First step: Launch two habitation modules (of modest dimensions). These are robotically capable of preparing for habitation ( Inflating, pressurizing cabins, etc.)

Send human crew who will exit the launch vehicles and enter, via ELV, the habitation modules.

The crew connects the two modules with a long cable, spins it up to produce a “bola” system, and conducts the first comprehensive experiments on the human requirements for artificial gravity during prolonged spaceflight. In 5 decades of manned spaceflight, we still do not

know how much “g” is needed to keep humans healthy indefinitely

Design Driver: Countering 0-g Effects

There is no completely satisfactory approach to countering 0-g effects aside from sustained artificial gravity.

We do not know how much “g” is required to maintain human health indefinitely (besides zero g = bad, and one g = good)

We will not know the answer to this for a long time, since long term experiments are required.

Therefore, we require: 1 g artificial gravity. Acceptable levels of Coriolis effects Exposure to 1g almost all the time

Orbiting Bolas = The first module in a series of permanently habitable platforms that return investment in space habitation

Establish long-term habitability requirements and solutions (gravity and radiation protection)

Partial implementation of HT

Space tourism Orbital debris clearance

and reclamation (moves several steps toward asteroid mining)

Test novel manufacturing processes exploiting vacuum and 0-g

2nd Step: Build infrastructure to enter the Interplanetary Super Highway

Establish Bola work stations and fuel cashes at the Earth-Moon, Sun-Earth L1 and L2 points

Tourism

Moon base transfer point

Astronomical observatories

NEA detection and monitoring

Bolas combine in an interplanetary space ship!

Take a Bola with 4 hab modules, add a walkway, cross truss, standoff truss and tensioned cable system an interplanetary craft with sufficient room for the full habitation technology

Interplanetary Spacecraft = Space Habitat with Propulsion

Up to 3 yrs. Trip Time12 Crew Members Full complement of habitation technology The Bola morphs into two segments of a torus Essentially the smallest self- sustaining system that can support a dozen people Can add hab modules and load-bearing cables to get a full torus (~150 people)

12

Rotation Axis

Bola Two Segments of a Torus!

Embed the hab modules in a stiff, light tensioned cable, compressed column structure – a proven approach to precision space structures.

Cables carry most of the centrifugal loading

Junctions are statically determinate, permitting accurate analysis

Stiffness is provided in all six rigid body hab module degrees of freedom.

Lowest vibration modes avoid frequencies that induce motion sickness

Design is expandable by adding more hab modules and more supporting cables

Note: Cross truss and rotation axis column serve to give sufficient stiffness.

Cross truss supports agg modules

Propulsion engines located at tips of cross truss. Protects Hab and Agg modules from radiation. Provides control authority for both cm acceleration and rotation control

Initial Deployment: Spiral out to E-M L114

Start in 300 km circular orbit about Earth

Spiral out to a coasting trajectory to the E-M L1 “throat”.

Meld into the Lyapunov orbit of L1 Station and refuel

Propellant mass: 20 MTTrip duration: 5.6 months

The L1/L2 region is the gateway to interplanetary space – where the spacecraft can “earn its keep”.

3385 10 km

Forbidden Zone

The comets and asteroids that are potentially the most hazardous because they can closely approach the Earth are also the objects that could be most easily exploited for their raw materials. This is why low energy trajectories through the interior

and exterior realms of the Sun-Earth system are of key importance

It has been estimated that the mineral wealth resident in the belt of asteroids between the orbits of Mars and Jupiter would be equivalent to about 100 billion dollars for every person on Earth today.

But we do not go to plunder the solar system of precious metals and deliver them to Earth, but to build new human communities in space.

Extractive economy? Development economy!

NEAR-EARTH OBJECTS AS FUTURE RESOURCES

From E-M L1 to S-E L2: Start of the First grand Tour (for mining)

Moon

L1 Lyapunov

Orbit

Orbit of the Moon

Earth-Moon Frame Sun-Earth Frame

L2

L2

L1

Sun

E-L1 to S-L2: V=12m/s, 50 days

122,720 km

After refueling, leave L1 on the outward invariant manifold.

Swing by the Moon and exit the E-M L2 throat in time to meld with a heteroclinic orbit leading to the Sun-Earth L2

Take one turn around the Lyapunov orbit and enter the external domain of the Sun-Earth system

Sun-Earth System

Asteroid Mining Tours: Exterior Realm

L1

1. Drop off cargo at L1 Station. Leave L1 Lyapunov orbit. Follow heteroclinic orbit to L2 (pink line, left to right) (drop off cargo at Earth-Moon system)

2. Meld into L2 Lyapunov orbit, follow for ¾ of a period, then follow the unstabile manifold (green line, heading down)

Sun-Earth Frame

L2

3.0 million km

Through S-E L2 to the Grand Tour of the Exterior Realm

Sun

3-2 resonance

Apophis

3. Follow the homoclinic, exterior domain orbit (green path issuing from L2 and going clockwise)

4. Mine Amors and Apollos on the way (3 years)

Then: see next slide

1 AU

Sun-Earth System

Heteroclinic Transfer Between Exterior and Interior Realms

L1

5. Follow homoclinic exterior domain orbit to L2 on the stable manifold (green line, pointing down, left). Refurbish and repair at L2 Station

6. Meld into L2 Lyapunov orbit, follow for ½ of a period, then follow the heteroclinic orbit to L1 (pink line, right to left).

7. Deliver cargo to Earth-Moon system. Meld into L1 Lyapunov orbit, Exchange crew and refuel at L1 Station.

8. Follow Lyapunov orbit for one period, then follow the homoclinic interior domain orbit (blue line heading to the left)

L2

3.0 million km

Through S-E L1 to the Grand Tour of the Interior Realm

Sun

3-2 resonance

Apophis

9. Follow the homoclinic, interior domain orbit (red path issuing from L1 and going counter clockwise)

10. Mine Atens and Apollos on the way (two years)

11. Then follow the stable manifold to L1 (blue line in previous slide, heading to the right).

12. Refuel and exchange crew at L1 station.

Go to step 1 and repeat.

Forbidden zone

Whereas asteroids are rich in the mineral raw materials required to build structures in space, the comets are rich resources for the water and carbon- based molecules necessary to sustain life.

In addition, an abundant supply of cometary water ice could provide large quantities of liquid hydrogen and oxygen, the two primary ingredients in rocket fuel.

As we begin to colonize the inner solar system, the metals and minerals found

on asteroids will provide the raw materials for more infrastructure, space colonies, and space ships. Comets will become the watering holes and gas stations for the interplanetary spacecraft.

Reference: Lewis, John S. Mining the Sky: Untold Riches from the Asteroids, Comets and Planets. Addison-Wesley, 1996.

NEAR-EARTH OBJECTS AS FUTURE RESOURCES (cont.)

Deep Space Voyagers becomes Space Colonies

Crew of 12

Colony of 150

“Mature” some spacecraft, growing them into complete tori and plant them as permanent stations (for resupply, repair and R&R) at Lagrange points or other orbital transfer points

For cargo or conventional vehicles, the interplanetary spacecraft can be complemented by the Rotovator

Surface of planet

Vo

= 2Vo/L

Cargo is released at 2V0, placing it into a hyperbolic

escape orbit

2Vo

Between cargo launches, an on-board low thrust

propulsion system performs orbit maintenance

Rotovators combine the efficiency of high Isp propulsion with the high thrust of chemical propulsion (but without chemical rocketry)

To design the rotovator, we need to find the variable cross section that will keep axial stresses below the ultimate yield stress of the

material

s

A(s) = r2(s)

L/2

= 2Vo/L

22t

t 2

The cross - sectional radius that makes the axial stress equal to a specified value, σ, is :

v 2s r s =rexp - -1

L4V

where:

t o

223 2 2 t t

t 2t

v =ΩL 2= tip speed = orbit velocity =V

σ V =tenacious speed= ( This is the key parameter!)

ρ

v vVL Total Mass =ρπ r exp ( when ≫1)

v V2V

Volumetric mass density =

Property

Material

Tensile Modulus

(109 N/m2)

Breaking Tenacity

(109 N/m2)

Density

(103 kg/m3)

Modulus speed

(km/s)

Tenacious speed

(km/s)

Kevlar 29 (w/resin) 83 3.6 1.44 7.59 1.58

Kevlar 49 (w/resin) 124 3.6 1.44 9.28 1.58

S-Glass 85.5 4.59 2.49 5.86 1.37

E-Glass 72.4 3.45 2.55 5.33 1.16

Steel Wire 200 1.97 7.75 5.08 0.504

Polyester 13.8 1.16 1.38 3.16 0.915

HS Polyethylene 117 2.59 0.97 11.0 1.63

High Tenacity Carbon 221 3.10 1.8 11.1 1.31

Carbon nanotubes 13,000 130 1.3 100 10

A Sample of Material Properties

tenacious speed = (Tensile modulus/ density)1/2

Rotovators can be fabricated within current technology

Rotovators can be made much smaller and much less massive than space elevators

Exotic, untested materials with enormous strength-to-weight ratios are not required

Can be fabricated from asteroidal materials Can be made as free-fliers (called rotors) for in

space orbit changes with large Vs Can be stationed at the L1/L2 gateways to

boost vehicles to Mars and beyond

The Rotovator (Rotor) as an Orbit Raising Device

Cargo in LEO

Rotovator in elliptical orbit

L1

Vmax

2Vmax-VLEO

o Cargo vehicle in LEO. Rotovator in elliptical orbit with rmin = rLEO+ L/2

o One end of rotovator hooks up with cargo. Rotovator makes one half turn and releases cargo at speed 2Vmax–VLEO

o Cargo travels on a much more eccentric ellipse – out to near L1

o Then cargo proceeds via a low-thrust trajectory to lunar orbit

Toward the Habitation of the Solar System

Send deep space voyagers to take up stations near the Moon, Mars, Mercury and the moons of Saturn and Jupiter

From these orbiting stations, plant ground-dwelling settlements with habitation technology modules (provided that adequate “g” is much less than 1g.)

Habitation technology modules will also be planted on Earth (perhaps in otherwise uninhabitable areas).

We will build a community of communities spanning the solar system – an Oikoumenê of many worlds!

An off-Earth economy will begin to grow – and ultimately dwarf that of Earth

Homes for all MankindRare minerals and metals

Advanced zero-g manufacturingProtection of the Commons

Discovery and new knowledgeInvention and scientific advance

What will life be like?

Small human communities will be spread across great distances Transport of bulk materials impractical Trade in rare commodities and devices Mainly trade in ideas, inventions and discoveries

Ethical norms are shaped by one’s way of life Space inhabitants confront cosmic necessities (not a man-made world) Truthfulness in everything is everything! Word of honor, not litigation. Generosity not acquisitiveness Enough for everyone is a feast!

Every human being will be precious Capital will bid for labor. People too few, not too many Oikoumenê of many worlds = The Household

A New Civilization?

In undertaking a great journey, people must choose what to take along and what to leave behind. The choice demands a decision about the most precious human

experiences

Every society has as its basis a fundamental human experience. Helenic – Beauty Siriac – Ultimate Spiritual Reality Western Christendom – Power of the Machine

Why not: Curiosity, Thrill of Discovery, and Awe?

The Answer: Yes!

Ad Astra!