396 



BENTHIC LABORATORY 



Fig. 153. The benthic laboratory operator's con- 

 sole at Scripps Institution of Oceanography 



resolution of the two cameras is made in Fig. 154. The vertical and radial position of the 

 manipulator was first established by use of camera 1 on the opposite side of the hive, then the 

 manipulator was rotated into the field of view of camera 2. After a considerable number of 

 trial approaches the manipulator hand was engaged in the card slot of one of the spare modula- 

 tor cards, and the card was extracted from its slot. The card was moved down to video 6 mod- 

 ule slot and successfully inserted. The engagement of the pins was indicated by the occurrence 

 of a strong interference pattern on TV channel 2. The card was then removed from this slot 

 and an attempt made to return it to the storage slot in its original location. At this point con- 

 siderable difficulty was encountered in aligning the card with the slot as a result of the poor 

 definition of camera 2. In the process of manipulation the card was dropped and lost from view. 

 A cursory examination of the hive with camera 1 did not disclose the final resting place of the 

 card; however, a more careful examination late that night revealed the card might be lodged in 

 the cable harness near the terminal block area (Fig. 155). Recovery of the card was considered 

 but the complete lack of visibility of this area from the camera 1 vantage point made it virtually 

 impossible, and no recovery attempt was made. 



The following day the hydraulic system was checked in an effort to determine the cause of 

 the accidental release of the card from the manipulator jaws. The integrity of the hydraulic 

 lines was investigated by listening to the cavitation of the hydraulic pump through the monitor 

 hydrophones and energizing the negative-pressure solenoid for the various functions intermit- 

 tently. If the pressure had remained the same in the circuit during the interval of time the 

 solenoid was closed, the flow through the pump would not be changed upon reactuation of the 

 valve. However, if the pressure had relaxed in the circuit, the reduction in pressure when the 



