2. Introduction
In reduced gravity <0.5g, running requires less energy
than walking
• In space, the pressure
inside space suits is high
enough that it helps
support the total weight
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.
pone.0006614#pone.0006614.s003
3. Introduction
Space suits affect the walk-run transition by mobility
restriction, changes in stability, and increased joint
mechanical work
4.
5. Introduction
Froude Number
By modeling walking as an inverted pendulum, we find
that walking occurs only when Fr≤1.
6. Introduction
Apollo Number
The Apollo number is defined as the Froude number
multiplied by the inverse of the mass ratio M.
When no space suit is present, M=1 and Ap=Fr
7. Variables
v=velocity
L=hip height or center of mass height
M=ratio of human carried mass to total transported
mass
g=gravitational acceleration
α&β=shape and location of the state transition
8. Physiological
The physiological variables include the length of the
leg, L, and the mass ratio, M.
When attempting to manipulate the Apollo number,
the variable M can be changed. This can give either a
higher or lower chance to be in a “run” state.
10. Recreation
MATLAB was used to recreate
Walk or Run state
Apollo Number
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.
pone.0006614#pone.0006614.s003
11. Alteration
Lower space suit
To allow a shorter weight/Shorter hip height
astronaut to run at the
same speed as a taller
Apollo Number
astronaut, the weight of
Higher space suit weight/
the space suit must be Longer hip height
altered.
Mass Ratio
14. Conclusion
In a suit with a higher mass, M, the walk-run
transition will occur at lower speeds
As loads reduce the self-support, M, walking becomes
possible at higher velocities
