NASA Research Scientist

Robert S. McCann, PhD
NASA-Ames Research Center

As a child, I was fascinated by astronomy and space exploration. I'll never forget trying to stay up the entire night of the Apollo 11-moon landing, just for the sheer excitement of it all. Alas, any hopes I might have had for a scientific career in physics or astronomy were dashed due to an insufficient aptitude for mathematics. So, I found myself in my first year of college taking a standard smattering of courses in the arts and sciences. One of them, introductory psychology, exposed me to the exciting new discipline of cognitive science, dedicated to understanding how intelligent systems work. My interest in this area was immediate and strong, and it propelled me through graduate school and on to an academic career as a cognitive psychologist.

Fate, however, determined otherwise. July 1986 found me nearing the completion of a doctoral program in experimental psychology at the University of Waterloo. One day, quite out of the blue, my dissertation advisor, Derek Besner, asked if I would be interested in taking a post-doctoral position at NASA-Ames Research Center in California's Silicon Valley. With visions of spacecraft, space science and various other enticements filling my head, I jumped at the opportunity.

Working for NASA has afforded me several opportunities to apply my knowledge of human information processing limitations to NASA's goals and missions. After completing my post-doc, I joined a project attempting to bridge the gap between basic research in visual attention and a practical problem in aviation human factors. The problem is with Head-Up Displays (HUDs), optical devices that project holographic images of an aircraft's instruments onto a glass panel mounted on the inside of the aircraft's windshield. Part of the rationale for developing HUDs was that they would help pilots be aware of and process HUD symbology in parallel with information in the out-the-window scene, such as an obstruction on a landing runway. However, research I did with one of my colleagues, David Foyle, suggested that true parallel processing of the two visual realms did not normally occur and became possible only when the HUD symbology was optically linked to the outside world.

At the time, our "optical linking" discovery was just that... a discovery in search of an application. However, it wasn't long before NASA researchers were tasked with developing cockpit displays that would help pilots taxi more efficiently at busy airports. Taxiing is actually one of the most demanding and hazardous components of a pilot's job, particularly in low visibility. To make the job easier, we designed an integrated system of surface navigation aids, including a new form of HUD symbology. Mindful of our earlier discoveries, we deliberately designed the new HUD symbology to perceptually "fuse" with the real world.

The result, which we called the Taxiway Navigation and Situation Awareness or T-NASA system, is now under commercial development by HUD manufacturers and avionics companies. We are hopeful that, if the system wins acceptance by the airline industry, terminal-area accidents, such as the recent Singapore Airlines disaster in Taiwan, will no longer occur.

As fulfilling as my work on T-NASA was, it is not the kind of space-related application that I originally associated with NASA employment. That opportunity finally surfaced last year. NASA has begun retrofitting the space shuttle cockpits with a suite of liquid-crystal displays (LCDs). LCDs provide much greater flexibility for displaying information than is the case in current cockpits. My colleague, Jeff McCandless and I are consulting with astronauts and mission operations specialists to design a new generation of shuttle displays that take advantage of this flexibility. The goals are to increase the safety of shuttle missions by providing the astronauts with a higher level of situation awareness than the current displays provide and to maintain that awareness with less mental effort.

My expertise in human information processing has come in quite handy in determining some features of these displays. Take the electrical power system, for example. Once the shuttle's power has been generated by fuel cells, it is distributed through a complex arrangement of buses, pumps, heaters and panels. The latest concept is to depict the distribution system as a 2-D layout of boxes connected by white lines representing the power flow. Suppose there is a fault in the system, and power is interrupted in a specific area. The astronauts need to be alerted to the problem as quickly as possible. The most obvious way to depict this is to simply remove the white line(s) connecting the affected components. However, basic research on visual attention has shown that humans don't notice the lack of a display feature very easily; they are much better at noticing a feature or object that has been added to a display. Thus, the better way to depict the loss of power to a component is to bisect the relevant white connector line with a red diagonal line. Subjectively, the red diagonal "pops out," alerting the crew more rapidly to the problem.

As NASA looks beyond the shuttle toward a new generation of reusable launch vehicles, possibilities for bringing human factors knowledge to spacecraft design are growing. So my lifelong interest in outer space and my academic training in "inner space" have come full circle. When it comes to career choices, the lesson here is flexibility. Unusual career paths can end up in very rewarding directions! For more information about careers at Ames, contact Robert S. McCann, PhD.

(Originally published in the March/April 2001 issue of Psychological Science Agenda, the newsletter of the APA Science Directorate.)