Well now that the 3rd and final EVA is over and the various solar panels and other equipment deployed, STS115 has done its job and the ISS has just had a major upgrade.

OTOH probably everyone here would (in an ideal world) have preferred available resources to be channeled into Lunar, or Mars, manne exploration. Most would probably call the Shuttle and the ISS a white elephant .. I would probably agree ..

And yet, isn't it great to have this giant structure in orbit - the industry must be gaining valuable construction experience in the process. These missions are still fascinating too.

More to the point: where would NASA and the US be if the shuttle fleet were grounded and the US could not keep to its agreements & commitments viz the ISS? Would that simply free the US to divert resrouces to the Moon, or Mars? Or, would the loss of international prestige ground all manned space flight for the forseeable future? I suspect the latter but will defer to more informed opinions.

The Shuttle /ISS might be a poor substitute for Mars but since it's all we have for now, NASA/Congress has been right to try to make it work and to keep to its commitments.