If you need to access information that was on on the amsat.org site then you can get some of it from the http://www.archive.org/ site

For example I wanted to look up info on RS-15, Google tells me it used to be at http://www.amsat.org/amsat-new/satellites/satInfo.php?satID=6

Putting that URL into archive.org page gives me the RS-15 info as it was on April 26, 2012

73 Trevor M5AKA