it's only there to take sonar pictures. the next step is to send down other submersibles that can do more. gary tuchman got an upclose look at one vehicle that played a key role in finding pieces of space shuttle "challenger." here's what he saw. >> reporter: at first glance it reis semables a spacecraft more than anything else but this is a research sub that has combed the seas doing everything from medical research to ship and aircraft recovery. >> we have an array of light systems on the sub. so you can turn on whichever light you need. >> reporter: jimmy nelson used to spend 170 days a year on the sub. the johnson seaing submersible. >> ready to go. >> ready to go. >> but other manned sea vehicles maybe next to line to aid in the malaysia airlines search. >> if this or another submersible can get where the wreckage is, how effect i have do you think at this time could