20 



MAJOR PROGRAM AREAS 



Fig. 14. The benthic laboratory is lowered into 

 the ocean from the Sealab II surface support vessel 



In addition to control and monitor functions associated with the operation of the benthic 

 laboratory, the electronics provides for the multiplex and demultiplex of quite a number of 

 television video, audio communication, and digital telemetering channels to and from Sealab 

 over the single coax to shore. The ac power required to operate the benthic laboratory is also 

 transmitted over the same coaxial cable. 



The bulk of shore-recorded data from Sealab is of questionable value, because conductors 

 carrying 3 of 18 bits telemetered ashore were intermittent due to connector failure in the 

 Sealab-to-benthic cables. Also, three of the four video coaxial connectors to benthic, along 

 with telemetered signals for focus and sensitivity adjustment, were lost during the initial 

 benthic -to-Sealab hookup as a result of the cable-connector damage. 



All audio communication channels performed as expected, and no failures occurred in the 

 42 days of operation while Sealab was manned. 



MINING TECHNOLCX3Y 



Two methods of mining/sample recovery were evaluated during Project Sealab II (Chapter 

 44). These two methods were airlift and the rotary corer. 



In the airlift method, a recovery pipe is suspended from a surface craft to the sea floor. 

 Compressed air is injected into the pipe some distance above the bottom, forming an aerated 



