Manual control in space--research on perceptual-motor functions under zero gravity condition

Area of Science:

• Human Factors and Ergonomics
• Spaceflight Physiology
• Control Systems Engineering

Background:

• Understanding human performance in microgravity is crucial for astronaut safety and mission success.
• Manual control tasks are essential for many space operations, yet are sensitive to altered sensory and motor feedback.

Purpose of the Study:

• To investigate the effects of microgravity on human manual control performance.
• To analyze changes in operator describing functions during and after spaceflight.

Main Methods:

• Manual control experiments using a finger stick to track a moving light spot were conducted pre-flight, in-flight, and post-flight.
• Operator describing function analysis was used to quantify control performance.
• Data collection included stick angle, light spot position, and subjective astronaut feedback.

Main Results:

• In-flight, the payload specialist experienced eye strain and difficulty maintaining body stability.
• Post-flight, temporary postural disturbances were observed.
• Operator describing function analysis revealed a disappearance of the 'regression' phenomenon and an increase in effective time delay during flight.

Conclusions:

• Microgravity significantly impacts human manual control capabilities, characterized by increased time delays and altered control strategies.
• These findings highlight the need for adapted interfaces and training for manual control tasks in spaceflight.
• Subjective astronaut reports correlate with objective performance data, emphasizing the multifaceted challenges of human spaceflight.