Human Factors and Maintainability in the Plant Research Unit (PRU)

The International Space Station (ISS) presents unique challenges in the field of maintainability engineering. Due to limited training time on earth and crew time in space, systems must be designed for ease of operation and maintenance.

The Plant Research Unit (PRU), an advanced plant growth facility, is required to operate on orbit with minimal crew interaction for maintenance. The PRU has been allotted one hour per increment for corrective maintenance, which consists of replacing Orbital Replacement Units (ORU) or incorporating workarounds. Designing highly maintainable systems is not possible without incorporating the principles of human factors engineering. The PRU has met the strict crew time requirements by combining those principles with maintainability engineering analysis techniques and then integrating them in the design process.