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