"All those industries that are based upon travel and tourism will shrink or, in some cases, disappear altogether as people are unable to go abroad like that."
"Do not think there is a lot of tourism in the Greater Community. Perhaps between trading nations there may be. It is the problem of biological hazards. You may travel to another world to visit a museum or some kind of natural feature of that world, but because you are not of that world, there is always the problem of biological contamination. And this problem has not been universally solved." <ref name="limits">The Limits of Space Travel (June 11, 2008)</rev>