CREATE TABLE table_70276 ("Start Date/Time" TEXT, "Duration" TEXT, "End Time" TEXT, "Spacecraft" TEXT, "Crew" TEXT)

What is the duration of the flight with end time of 21:06?
SELECT "Duration" FROM table_70276 WHERE "End Time" = '21:06'
SELECT "Duration" FROM "table_70276" WHERE "End Time" = '21:06'