The Sovjet-Union had many different medals and orders. They had different campaign medals for indeed the defence of Stalingrad, but also Leningrad and Moskow. For an overview Sovjet-Union medals I would recommend to have a look here:
World War 2 Awards.com - U.S.S.R.
You will find there information about different medals and order of the Sovjet-Union and the receipients!
Best Regards,
Sebastiaan