This summer, as the world looked back 40 years to the day man first landed on the moon, many were also looking forward and wondering when he would return. There has not been a lunar landing since 1972, and as the glories of the Apollo 11 mission were recalled--the audacity of taking a walk on the moon, mainly to show that it could be done at all--there was a call for renewed commitment to manned space exploration. But critics question why we would make such an enormous investment again when almost all our scientific objectives can be met with unmanned rockets and rovers.

This is not a new debate, of course. Forty years ago, in the issue immediately following the successful lunar landing, Technology Review devoted two pages to a dispatch from the legendary journalist Victor Cohn detailing a contentious and surprisingly public tussle between scientists and NASA officials in what should have been the agency's finest hour.