An undetected leak in the Agena fuel transfer equipment at the 

 launch pad resulted in an elliptical orbit rather than the desired 

 circular orbit with a resulting apogee of 922 km. ( 503 nm. ) and a 

 perigee of 423 km. (228 nm. ) • As a result, not all data recorded 

 on the spacecraft could be read out and there were gaps in the sensory 

 data coverage for this reason. 



On 23 September I96U, after 26 days of operation, the solar array 

 drive jammed. Since the solar array was in the sunrise position, 

 some solar power was received, but not enough to operate the essential 

 spacecraft systems. After seven orbits, battery discharge reached a 

 point where attitude control and telemetry failed. 



During the 26 days of operation there were a total of 379 orbits. 

 Of these, 125 were blind because spacecraft command was not feasible 

 at either CDA site; 73 of these blind orbits were the result of the 

 eccentric orbit. Of the 25^ orbits on which data could have been obtained, 

 some were missed because of short acquisition times, others because of 

 a conservative doctrine which dictated the turn-off of sensory systems 

 when spacecraft operational problems were encountered. 



Despite its short life, Nimbus 1 made important contributions to 

 the use of satellites as remote observatories. In the interest of 

 ocean studies, Nimbus 1 proved the practicality of the HRIR system and 

 provide the first high resolution infrared data and television pictures 

 of the earth on a global scale. 



Nimbus 2 was launched on I5 May I966 from the Western Test Range 

 in California. A near-circular orbit of an average altitude of 1,137 km. 

 (61^1- nm. ) was achieved, with an apogee height of 1,179 km. (636 nm. ) , 

 a perigee height of 1,095 km. (591 nm.), and an inclination of 100. 3°- 



54 



