company that made the original flight data recorders. thanks for being with us. as you know, the sophisticated equipment on board this australian ship has twice picked up the signals. do you think they are the pings from the black boxes? what would lead us to believe that they could be? >> well, as we have talked ab, it's a very unique signature, the 37.5 kilo hertz. it sounded like a steady continuous signal from one of our pingers so we are very cautiously optimistic. >> 37.5 kilohertz doesn't happen in nature. that means that the battery has lasted longer than 30 days. we knew that the batteries could have expired by that point. what's the best case scenario on how much longer the battery can power the pinger? >> well, we have some design