Echo 2 [NASA]
The Echo 2 spacecraft was a 41-m balloon of aluminum foil-mylar laminate. Echo 2 was designed as a rigidized passive communications spacecraft for testing propagation, tracking, and communication techniques. Instrumentation included a beacon telemetry system that provided a tracking signal, monitored spacecraft skin temperature between -120° C and +16° C, and measured the internal pressure of the spacecraft between 5E-5 mm of mercury and 0.5 mm of mercury, especially during the initial inflation stages. This system, which consisted of two beacon assemblies, used solar cell panels for power and had a minimum power output of 45 mW at 136.17 MHz and 136.02 MHz.
Befor the orbital flight was made, two suborbital tests called Big Shot were made. Big Shot 1 failed, when the balloon ruptured during inflation.
In addition to fulfilling its communications mission, the spacecraft was used for global geometric geodesy. The spacecraft re-entered the atmosphere on 7 June 1969.
|Type / Application:||Communication, passive|
|Contractors:||G. T. Schjeldahl Co. (Balloon); Kaiser-Fleetwings Co. (Container)|
|Configuration:||Balloon, 41 m|
|Power:||Solar cells, batteries|
|Orbit:||1029 km × 1316 km, 81.5°|
|AVT 1 (Big Shot 1)||N/A||15.01.1962||CC LC-17A||*||Thor-DSV2D|
|AVT 2 (Big Shot 2)||N/A||18.07.1962||CC LC-17A||*||Thor-DSV2D|
|Echo 2 (Echo C)||1964-004A||25.01.1964||Va 75-1-1||Thor-DM21 Agena-B|
* = suborbital test