Malaysian official raises the possibility of more underwater search vehicles . Underwater probe heads out for second mission , no 'contacts of interest ' yet . After the latter was resolved , officials dipped it into the ocean again . Dolan has covered over 370 miles in nearly a quarter trips . A preliminary analysis of an oil sample shows that it is not aircraft engine oil .
Malaysian official raises the possibility of more underwater search vehicles . Underwater probe heads out for second mission , no 'contacts of interest ' yet . Dolan has covered over 370 miles in nearly a quarter trips . A preliminary analysis of an oil sample shows that it is not aircraft engine oil .