CREATE TABLE table_17726 ("Ship" TEXT, "Builder" TEXT, "Namesake" TEXT, "Renamed" TEXT, "Laid down" FLOAT, "Launched" TEXT, "Commissioned or completed ( * ) " TEXT)

When was the ship launched when the commissioned or completed(*) is 6 june 1864?
SELECT "Launched" FROM table_17726 WHERE "Commissioned or completed(*)" = '6 June 1864'
SELECT "Launched" FROM "table_17726" WHERE "Commissioned or completed(*)" = '6 June 1864'