CREATE TABLE table_12856 ("Designation" TEXT, "Launch date/time  (  GMT  ) " TEXT, "Mass" TEXT, "Apogee" TEXT, "Inclination" TEXT)

What is Mass, when Designation is Prognoz 2?
SELECT "Mass" FROM table_12856 WHERE "Designation" = 'prognoz 2'
SELECT "Mass" FROM "table_12856" WHERE "Designation" = 'prognoz 2'