A reality check on dreams for space: the repairs, Christian Science Monitor
"The farther from Earth astronauts travel, the more acute maintenance challenges become, notes Larry Bell of the Sasakawa International Center for Space Architecture at the University of Houston. Planners try to build redundancy into critical systems and to provide the tools and materials for making some repairs. Indeed, one tool Parazynski used to handle the undulating solar array took shape from a sheet of Teflon and some insulating tape in the space station's workshop. But mission planners always face a trade-off between trying to plan for maintenance needs and keeping materials within the weight limits during launch. Especially when talking about trips to the moon or Mars, "it's a long way back to the hardware store," Dr. Bell says."