Good Use of Flight Crew Time - A Guiding Principle for EVA System Design 941556

A fresh look at the use of astronaut time to conduct and support Extravehicular Activity (EVA) can help guide the evolution of next generation EVA systems. Studies have shown that less than 20% of the flight crew time for EVA (prior/during/post) is currently spent directly on productive tasks. In the future, longer missions, larger and more complex orbiting platforms and on-orbit maintenance of EVA equipment will drive this percentage even lower. Study of where the remaining 80% of the flight crew time presently goes indicates where improvements could be aggressively pursued for next generation systems. With the high cost per manhour on orbit, and estimated needs for 200 or more crew hours of EVA annually for space station, these improvements are clearly worthwhile.

Current use of crew time before, during and after EVA were analyzed, and major uses of time identified. Some specific areas highlighted include IV support, servicing and checkout, prebreathe, tool management, and translation and position maintenance. Careful attention to these elements in an integrated, total EVA system definition could significantly reduce the unproductive expenditures of a precious resource. This will allow our future space missions to be more productive as well as faster, better and cheaper.