Motivation: Why Artificial Gravity?
Current countermeasures are not
sufficient to prevent the
detri
m
ent
a
l physiologi
cal ef
fects
of long-
d
urati
o
n s
p
ace fli
g
ht
Types of Artificial Gravity
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The Potential New R
x
?
“Spin in the Gym”
?
“Prescribed AG Dosage”
?
“AG Sleeper”
Intermittent Short-Radius
Centrifugation
?
Cost-effective
?
Space-ef
ficient
?
Relatively easy to implement
?
Fits w
i
thin
ISS/Spacehab
Intermittent Short-Radius Centrifugation
Out-of-plane head movements
d
u
ring rotation
produce
sensory conf
lict
vestibular vs. visual and kinest
hetic
–
Inappropriate non-compensatory
n
ystagmus
–
Motion sickness
–
Illusory tilt sensations
–
Postural instability
Artificial Gravity Level Tradeoff
30
0
5
10
15
20
25
30
35
40
45
50
55
Radius (in m)
4-
m
a
n
Ehrick
e
8-
m
a
n
Von Br
aun
PG
Kr
am
e
r
&
B
y
e
r
s
1.0g
0.
277
g
Schnit
z
er
MIT
Di
am
andis
Major Features of Rotating
Environment
Artificial Gravity Level (Centripetal Accel.)
r
ωωωω
2
Cori
olis Forces
-2
m
(
ωωωω
x
v
)
Gravi
ty Gradien
t
s
h/r
Cross-
coupled Angul
a
r Accelerati
o
ns
ωωωω
SRC
x
ωωωω
Head
Stimul
us
Schematic of MVL Short-Radius Centrifuge
mo
t
o
r
lights
t
a
c
h
o
m
et
er
r
e
ducer
co
unt
erweigh
t
belt
pitch dial
slip ring
1.
9 m
head r
e
st
ca
m
e
ra
foot plate
eye
dat
a
ti
m
e
r
0:10:25
co
nt
roll
er
TV
TV
for cam
era
VCR
VCR
w
i
rele
ss hear
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rat
e
m
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ito
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MIT Short-Radius Centrifuge
?
2 meter radius platform
?
Variable ro
tation ra
te
?
100 %
gravity gradient along lon
g
itudinal b
o
dy axis
Hypothetical Canals
Right Ear Do
wn Position
(RED)
Nose Up Position
(NU)
Roll
Ca
nal
Pitch
Canal
Pitch
Canal
Roll
Ca
nal
Response of the
cupula
90 degree yaw
head turn
on a 23 rpm
centrifuge from
the “right ear down” to “nose up” position
Base
d
on
Y
o
u
n
g
-
Oma
n
L
a
p
l
a
ce
t
r
an
sf
er
f
u
n
c
t
i
o
n
mo
del
Semicircular Canal:
Cupula
Dynamics
0
5
10
15
20
25
30
35
40
-0
.
5 0
0.5
1
1.5
2
2.5
Roll Canal
0
2
4
6
8
10
12
14
16
18
-0
.
5 0
0.
5 1
1.
5 2
2.
5 3
3.
5
Yaw Canal
0
5
10
15
20
25
30
35
40
-2
.
5
-2
-1
.
5
-1
-0
.
5 0
0.
5 1
1.
5 2
2.
5
Pitch Canal
E
xperimental findings (MVL 2000)
–
Head movements during short-radius centrifugation have disturbing side-effects, not all of w
h
ich can be predicted by a semicircular canal
model
–
All side effects are subject to partial adaptation
–
Generaliz
a
tion of adaptation to different head-
movements and to different rotating environments remain to be investigated
–
Short-radius centrifugation is a most promising stepping stone to stay healthy on the
way to Mar
s