1g and 0g Analogs & Simulations

ASEN 5016 Lecture 22: 1g and 0g Analogs / Simulations

OBJECTIVES

1. Describe typical methods (along with attributes and shortcomings) for simulating 0g on Earth

2. Describe typical methods (along with attributes and shortcomings) for simulating gravity in space

What is an analog(ue) anyway?

Simulated vs. Real 0g

Simulated vs. Real 1g

How can gravity be simulated? Point Source vs. Body Force

· Point Source à external load

· Body Force à acceleration, magnetism

Simulating (aspects of) weightlessness on Earth

Simulating (aspects of) gravity in Space

Lower Body Negative Pressure (LBNP) ~50 mm Hg vac = ~1/2 normal BP

Russian Penguin suit used on orbit – tonic stressor

Exercise Equipment

Cycle Ergometer w/ Vibration Isolation & Stabilization (CEVIS)

Treadmill w/ Vibration Isolation & Stabilization (TVIS)

Isolated Resistive Exercise Device (IRED)

Electrostimulation - Muscle Tone (Russian)

Inflatable insoles?

Magnetic shoes?

Vibration therapy?

Diamagnetism (similar idea to levitation described above)

Creating artificial gravity in space

Linear acceleration -- or -- Rotation Induced Artificial Gravity Environment (centrifugation / centripetal acceleration)

What are the tradeoffs? mass / cost / complexity / need / physiological issues

Rotating environment

· Variable-g levels / g-gradients

· Coriolis force

· Cross-coupled angular acceleration

· Mechanical / structural issues

How much is enough? -- 1g, 1/2 g, 1/3 g, 1/6 g…

How long is long enough? -- Continuous? Half time? During exercise? Sleeper compartment?

1. Consider all the variables and forces acting on the system

2. Draw a Free Body Diagram

3. Add or remove forces, as applicable, for desired simulation

4. Correlate the physical factor(s) to the biological response(s)

5. Establish a cascade of events and define cause-and-effect relationships

And briefly, if we have time, a different application of simulated environments, related space flight operational analogs…