CREATE TABLE table_78653 ("Date and time (  UTC  ) " TEXT, "Type" FLOAT, "Serial no." TEXT, "Launch site" TEXT, "Payload" TEXT, "Type of payload" TEXT, "Orbit" TEXT, "Outcome" TEXT)

For the payload of Van Allen Belts Exploration what's the serial number?
SELECT "Serial no." FROM table_78653 WHERE "Type of payload" = 'van allen belts exploration'
SELECT "Serial no." FROM "table_78653" WHERE "Type of payload" = 'van allen belts exploration'