Is there a web version of this? It's too bad if all this great information is hidden away in a PDF, which few will bother to open (even on HN, and fewer in the general public) and which I'll probably be unable to find in the future. I found the following website, but my initial impression is that it's lacks a lot of the great material in the PDF:
http://www.nasa.gov/topics/journeytomars/index.html