CREATE TABLE table_26988 ("Expedition" CLOB, "Crew" CLOB, "Launch date" CLOB, "Flight up" CLOB, "Landing date" CLOB, "Flight down" CLOB, "Duration  ( days ) " CLOB)

Name the launch date for vladimir lyakhov , aleksandr pavlovich aleksandrov
SELECT "Launch date" FROM table_26988 WHERE "Crew" = 'Vladimir Lyakhov , Aleksandr Pavlovich Aleksandrov'
SELECT "Launch date" FROM "table_26988" WHERE "Crew" = 'Vladimir Lyakhov , Aleksandr Pavlovich Aleksandrov'