Pedalling in space as a countermeasure to microgravity deconditioning

Area of Science:

• Space exploration
• Human physiology
• Biomechanical engineering

Background:

• Microgravity causes physiological deconditioning in astronauts.
• Artificial gravity is a potential solution to mitigate these effects.
• Existing artificial gravity methods may have drawbacks.

Purpose of the Study:

• To propose and analyze a novel system for generating artificial gravity.
• To simulate a gravity environment using counter-rotating bicycles within a space module.
• To evaluate the feasibility of this system for preventing microgravity deconditioning.

Main Methods:

• A system of two mechanically coupled, counter-rotating bicycles was modeled.
• Subjects pedal on the inner wall of a cylindrical space module.
• Centrifugal acceleration (ac) was calculated based on peripheral velocity (v) and radius of gyration (R) using ac = v²/R.
• Mechanical (w) and metabolic (VO2) power requirements were determined.
• Arterial pressures at head and feet levels were calculated.

Main Results:

• Simulated gravity (ac) is achievable by adjusting pedaling velocity (v).
• Calculations for R=2m and R=6m showed varying v, w, and VO2 requirements.
• Arterial pressure gradients were estimated for different simulated gravity levels.
• The system can generate significant centrifugal acceleration.

Conclusions:

• The proposed system offers a method to combine exercise with simulated gravity.
• Optimizing radial dimensions minimizes vestibular disturbances and acceleration gradients.
• This approach could prevent microgravity deconditioning without external power input.