The Martian Obelisk

This story is about an Earth that is dying from multiple causes and a Mars project that has been long abandoned. An Earth engineer's last project is to be a monument to celebrate all that humanity stood for. The Mars Obelisk would be the one last thing to say that we were here, before everything died. No one would be alive to see it, of course, but such is humanities egotism.

Then suddenly the impossible happens, they see signs that someone is still alive on Mars, and they need to build a habitat for themselves and the only realistic way for that to happen is to sacrifice the obelisk. The only thing stronger than humanity's ego, is the one word: Hope.