328 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1963 



opaque in the ultraviolet). We decided therefore to take a more 

 cautious approach and first use Stratoscope II for a study of the infra- 

 red spectrum of Mars during its opposition early in 1963. Strato- 

 scope II was ready for infrared spectrophotometric research in 

 February of this year and was laimched on its first flight on the eve- 

 ning of March 1. The events of that night could not have been more 

 exciting for any of us involved. 



The late afternoon launching went entirely smoothly ; the specially 

 designed balloon, capable of flying a gross load of 13,000 pounds, 

 lifted the 3-ton telescope off the ground by a newly developed static 

 launching method with accelerations not exceeding 0.2 g. In the 

 meantime the ground station had been set up about 200 miles down- 

 wind along the predicted flight path for the night. This ground 

 station provided a link between the engineers and scientists in it and 

 the telescope high above it that was far more extensive and versatile 

 than that used in Stratoscope I. In total more than 70 different com- 

 mands could be transmitted to the instrument and a similar number 

 of data relative to the telescope could be read in the ground station 

 via a telemetry channel. Even a full-scale television channel was 

 available to make possible the acquisition of any object in the sky. 

 Through these radio links Stratoscope II is perhaps at the moment 

 the most versatile scientific robot operated from a far distance by 

 man. 



Plowever, as might not be so unexpected, this robot misbehaved in 

 a variety of ways during his first flight. A series of inadequacies and 

 direct failures occurred throughout most of the night. The versa- 

 tility of the command system made it possible, however, to analyze 

 the difficulties sufficiently well to make possible their correction prior 

 to the next flight, and even to overcome to a certain extent their nega- 

 tive consequences during that first flight. This series of technical 

 difficulties greatly reduced in quality and quantity the scientific ma- 

 terial acquired during the night. Nevertheless, it was possible in 

 the last observing hour to obtain a number of tracings of the infrared 

 spectrum of Mars which in combination with the recent observations 

 from the ground in other wavelength regions have already contrib- 

 uted to our knowledge about the chemical composition of the Martian 

 atmosphere. 



At the end of the night, when the observational work had been 

 concluded, one more hair-raising complication occurred. The descent 

 of the balloon was initiated by a radio command which opened the 

 helium valve at the top of the balloon. After the valve had opened 

 and enough helium had escaped to give the balloon the appropriate 

 moderate descent rate, another command was given to close the helium 

 valve to avoid any further acceleration. This command failed and 

 in spite of a variety of experiments the helium valve could not be 



