Recently NASA had located the wreckage of Mars Polar Lander and the location of Viking 2:
http://www.spaceref.com/news/viewsr.html?pid=16493"we can now add with certainty Viking Lander 2 (VL-2), the location of which has been uncertain by many kilometers for nearly 30 years. We also believe that we have found a candidate for the location of the Mars Polar Lander, which failed without a trace on 3 December 1999."
What happen if the future Mars explorer robots find the location of the wreckage, what should NASA do with the wreckage:
1. Bring it back to earth and put it on Smithsonian museum.
2. Recycle it for creating new base.
3. Leave it alone.
