Space Human Factors Engineering

    Space Human Factors Engineering Project

    The Space Human Factors Engineering (SHFE) project provides critical answers for the design of the next generation of NASA human spaceflight systems. To ensure that humans can perform exploration missions safely and effectively, SHFE scientists and engineers conduct studies in a variety of settings, from the laboratory to analog environments to spaceflight. They collect the information needed to verify that the crew’s work environment, tools, and interfaces with complex systems support their tasks. The SHFE team works closely with design and space operations experts to ensure appropriate and timely solutions to their human-systems integration issues.

    Acoustic Model Delivered to Orion Project

    The Acoustics Modeling team's accomplishments included advancing the validation of acoustic modeling techniques, participating in a collaborative acoustic modeling effort on the Orion and Crew Module mockups, and identifying and validating specific noise controls for use in the Orion vehicle.

    The acoustic modeling method was validated with respect to secondary structures such as closeout panels. In particular, the acoustic transmission properties of the Orion secondary structure partition that separates the crew habitable volume from the environmental control system’s fans and pumps was modeled and mocked up with a realistic fan noise source located behind the partition. The predictions and measurements were in good agreement, thus validating the modeling approach.

    A detailed acoustic model of the Orion Crew Module was also developed. This model was used to advocate the development of “system-level” noise treatments to aid in the global reduction of noise levels in the Crew Module. The benefit of this approach was to enable development of component noise allocations to meet the acoustic requirements.

    Finally, the team made recommendations of noise treatments, specifically the acoustical sealing of gaps and the addition of acoustically absorbent treatments to some surfaces inside the Crew Module. This information, along with results from further trade studies in the modeling of noise control, acoustic investigations of flight materials, and implementation studies, was presented to management to obtain a mass budget of 35 lbs and hardware ownership of the noise treatments for implementation.

    Usability Research: Development and Testing of a Maneuverability Assessment Scale

    A number of objective and subjective human factors measures have been used to assess the fit and operability of the EVA spacesuit, including task completion times and errors, and workload and perceived exertion scales. Over the course of a large number of suit evaluations, it was noted that although subjective comments hinted at issues with ease of movement, none of the metrics directly measured the concept of maneuverability.

    Evaluation in the Neutral Buoyancy Laboratory at JSC, Houston, Texas: Crewmember responding to the Maneuverability Assessment Scale (MAS) in the Orion mockup.
    Maneuverability is a crucial factor in the design of spacecraft, tools and control interfaces. As part of the HRP Usability Directed Research Project, a maneuverability scale was developed and tested for use in evaluating a crewmember’s ease of movement while suited and unsuited in confined spaces. The Maneuverability Assessment Scale (MAS) is a five-point scale, ranging from 1 – Excellent to 5 – Very Poor, that measures the ability to move in any direction with the desired pace and accuracy.

    The MAS has been evaluated in several studies. A 2010 study evaluated factors affecting maneuverability with more than thirty participants in a task that involved donning and doffing a flight suit in an open laboratory setting and in an ISS crew quarters mockup. As a result of the study, a modified MAS was developed and field tested with six participants in an evaluation of removable hand rails for Orion at the JSC Neutral Buoyancy Laboratory.

    Vibration Research

    Evaluation in the Neutral Buoyancy Laboratory at JSC, Houston, Texas: Crewmember responding to the Maneuverability Assessment Scale (MAS) in the Orion mockup
    HRP’s Information Presentation Directed Research Project has conducted a series of studies focusing on human visual and manual performance capabilities in severe vibration environments – such as those experienced during a launch event. Astronauts’ experien ce, along with data from these studies, supported the development of Constellation Program requirements on vibration limits. This design enables crews to visually monitor vehicle function during a vibration event and assume manual control after the event had ended.

    In 2010, data collection and analyses were completed for the final three vibration studies funded under the current Information Presentation Project. These studies investigated the relationship between differing types of whole-body vibration and their disruptive effects on display-reading performance and cursor control.

    The first study indicated that the visual performance disruption caused by pulsed chest-to-spine vibration was commensurate with that produced by an equivalent constant vibration. The second study demonstrated the potential benefit of a generally applicable countermeasure technique for improving the readability of visual displays by observers undergoing whole-body vibration. The third study showed that although cursor control operation degraded as amplitude increased for single frequency chest-to-spine vibration, the pattern of the vibration effect was the same for each cursor control device (CCD). Cursor modes that were more constrained, such as those allowing only left to right movement, were more affected by vibration than other cursor modes.

    The results of this work will help guide the design of human system interfaces for high vibration environments and aid in the formulation of performance-based requirements for future human space missions.