For "cover", you could also say "envelope". What is meant in the philatelic context is
- usually a size 6 white envelope
- with a stamp
- and a postmarker of the place and the date of an event which it commemorates.
- Often, these covers also have printed or rubber stamp illustration. That is commonly called a "cachet".What most collectors do to obtain their covers is to prepare their own envelope, put a stamp on it, and send it to the relevant post office requesting cancellation on this or that day, joining another stamped and addressed envelope for return.
For manned missions, the most appropriate post office is the Kennedy Space Center office in the NASA HQ building. The same for the landing. Houston where mission control is located is also an interesting location to obtain covers from.
For unmanned launches, the Cape Canaveral post office is good.
Of course there are many other launch sites in the US as abroad, but I don't want to be too confusing.
If you have more questions, just ask.
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Jürgen P Esders
Berlin, Germany
http://groups.yahoo.com/group/Astroaddies