The Architecture ofArtificial-Gravity Habitats

Theodore W. Hall

Future in Space Operations (FISO) Colloquium17 November 2010 1

The Architecture ofArtificial-Gravity Habitats

Theodore W. Hall

Future in Space Operations (FISO) Colloquium17 November 2010 2

Education: ArchitectureB.S. ’79, M.Arch. ’81, Arch.D. ’94: University of Michigan

Experience: Software Development’80-’94: Systems Research Programmer

Architecture and Planning Research LaboratoryUniversity of Michigan

’94-’04: Postdoctoral Fellow & Research OfficerDepartment of ArchitectureChinese University of Hong Kong

’09- Research Computer SpecialistUniversity of Michigan 3D Lab (UM3D)

“Expensive Hobby”: Space Architecture• Dissertation: “The Architecture of Artificial-Gravity Environments

for Long-Duration Space Habitation”• http://www.artificial-gravity.com/• http://www.spacearchitect.org/

My Background. 3

Adverse Effects of Micro Gravity:• Fluid redistribution• Fluid loss• Electrolyte imbalances• Cardiovascular changes• Red blood cell loss• Muscle damage• Bone damage• Hypecalcemia

Why Artificial Gravity? 4

Adverse Effects of Micro Gravity:• Immune suppression• Cell membrane thickening• Vertigo and disorientation• Nausea and malaise• Exercise incapacity• Olfactory suppression• Weight loss• Flatulence

Why Artificial Gravity? 5

Adverse Effects of Micro Gravity:• Facial distortion• Postural changes• Coordination changes

Why Artificial Gravity? 6

Why Artificial Gravity? 7

Historical Concepts.

Tsiolkovsky, 1903 Noordung, 1928

von Braun, 1952 Lockheed Corp., 1960

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Historical Concepts.

NASA LaRC & North American, 1962 Inflatable concept, 1962

9

Comfort chart, Hill and Schnitzer, 1962. 10

Comfort chart, Gilruth, 1969. 11

Comfort chart, Gordon and Gervais, 1969. 12

Comfort chart, Stone, 1973. 13

Comfort chart, Cramer, 1985. 14

Fundamental weaknesses:

• Too abstract.

• Too precise.

• Too difficult to read.

Comfort charts. 15

Comfort chart, composite. 16

SpinCalc artificial-gravity calculator. 17

SpinDoctor artificial-gravity simulator. 18

Dropping particles, inertial view: h/Rf 19

Dropping particles, rotating view: h/Rf 20

Hopping particles, inertial view: v/V 21

Hopping particles, rotating view: v/V 22

Hopping particles, rotating view: v/V 23

Acceleration ratio: 2 v/V 24

Earth gravity. 25

Artificial gravity at the limits of “comfort”. 26

min. radius and velocitymin. mass and energy

Artificial gravity at the limits of “comfort”. 27

Artificial gravity at min. “comfort” R & V. 28

Basketball in 1-g artificial gravity: free-throw. 29

Basketball in 1-g artificial gravity: under the net. 30

Apparent slope of flat floor. 31

Apparent slope of flat floor: catenary arch.

ηq

=−cosηξq

⎛⎝⎜

⎞⎠⎟ ;

Aq

=Ω 2 cosηξq

⎛⎝⎜

⎞⎠⎟

ηq

=−cosηξq

⎛⎝⎜

⎞⎠⎟ ;

Aq

=Ω 2 cosηξq

⎛⎝⎜

⎞⎠⎟

32

Apparent slope of straight ladder: catenary arch.

ηq

=−cosηξq

⎛⎝⎜

⎞⎠⎟ ;

Aq

=Ω 2 cosηξq

⎛⎝⎜

⎞⎠⎟

33

Orient ladders normal to Coriolis acceleration. 34

Orient ladders normal to Coriolis acceleration. 35

Orient ladders normal to Coriolis acceleration. 36

R = 67.1 mV = 14.0 m/sv = 1.0 m/sx = 3.8 mslope = 4º

= 7% grade= 1:15

Apparent slope at min. agreed “comfort” R & V. 37

Apparent slope at min. agreed “comfort” R & V.

R = 67.1 mV = 14.0 m/sv = –0.5 m/sx = 0.0 mlean = 4º

38

“BNTR Artificial Gravity Mars Mission.”[Borowski, Dudzinski, Sauls, Minsaas, 2006]

Greater apparent slope at smaller R & V. 39

Acent = 0.38 gΩ = 4.0 rpmR = 21.2 mV = 8.9 m/s

Greater apparent slope at smaller R & V.

“BNTR Artificial Gravity Mars Mission.”[Borowski, Dudzinski, Sauls, Minsaas, 2006]

40

Greater apparent slope at smaller R & V.

“BNTR Artificial Gravity Mars Mission.”[Borowski, Dudzinski, Sauls, Minsaas, 2006]

41

floor slope = 13ºladder lean = 6º

Greater apparent slope at smaller R & V.

“BNTR Artificial Gravity Mars Mission.”[Borowski, Dudzinski, Sauls, Minsaas, 2006]

42

Ladder in side wall – not recommended.

“2001: A Space Odyssey.”[Kubrick, Clarke, 1968]

43

“2001: A Space Odyssey.”[Kubrick, Clarke, 1968]

Ladder in side wall – apparent lean. 44

“VGRS.”[Emmart, 1989]

Ladder in side wall – not recommended. 45

Module Orientation.

AxialMost comfortable:• No Coriolis.• No apparent slope.• No floor curvature.• No ladders.• No gravity gradient.

Least stable?• Twists to tangential.

46

Module Orientation.

TangentialMedium comfortable:• Coriolis.• Apparent slope.• Floor curvature.• No ladders.• No gravity gradient.

Medium stable:• Needs balance.

47

Module Orientation.

RadialLeast comfortable:• Coriolis.• Ladders.• Gravity gradients.• Disoriented plan.

Most stable.

48

Experiments in form and color for orientation. 49

Experiments in form and color for orientation. 50

Experiments in form and color for orientation. 51

Observations.

• Cost trade-offs:

decrease:radius, velocity, mass, energy.

increase:research, testing,design review, selectivity,training, acclimitization.

52

Observations.

• The habitat pressure shell does notshield the interior from physics andmechanical dynamics.

53

Recommendations.

• Curve floors that are wide relative tothe rotational radius.

• Reject circular plans with noobvious orientation to the directionof rotation.

• Use color and pattern to providevisual orientation to distinguisheast (fore, prograde) from west(aft, antigrade).

54

Recommendations.

• Avoid multistory designs.

• Place ladders coplanar to the axis ofrotation, perpendicular to theCoriolis acceleration.

• Provide separate ladders (or two-sided access) for ascending anddescending.

55

Recommendations.

• Question all assumptions aboutgravity.

• Question everything.

56

URLs for SpinCalc and SpinDoctor.

http://www.artificial-gravity.com/sw/SpinCalc/SpinDoctor/

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Discussion. 58