NSSDCA ID: 1967-038A-02
Mission Name: San Marco 2The San Marco 2 air density accelerometer experiment, similar to the experiment on San Marco 1, was designed to measure the equatorial upper atmospheric air density as a function of local time and geomagnetic activity. Unique features of the experiment included (1) a direct and continuous record of the aerodynamic drag, (2) an equatorial orbit that allowed density measurement to be taken at the same point in space at 90-min intervals, and (3) a very efficient data acquisition coverage that was due to the satellite passing over the same station about 15 time per day. The structure of San Marco 2 formed an integral part of the experiment. The instrumentation consisted of two parts -- the spacecraft's outer shell, which was subject to drag effects, and a heavy inner structure that contained all the satellite instrumentation and power supply. The outer shell was connected to the inner structure through a series of flexible arms. An elastic drag balance system was able to detect the displacement of the outer shell, subject to the aerodynamic force, with respect to the inner body both in value and direction, resolving any relative translation along three mutually orthogonal axes. The balance displacements were converted to electric signals and were telemetered almost instantaneously via the PAM-FM-FM system to either of two ground-based stations. A total number of 672 passes and a total acquisition time of 4080 min were obtained for the experiment during its operational lifetime from April 26 to July 15, 1967. Particular attention was devoted to the study of the variation of the air density with geomagnetic activity from May 3, to June 1, 1967, a period in which a sequence of quiet days was interrupted by a very strong geomagnetic storm.
Mass: 128.3 kg
Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office
Name | Role | Original Affiliation | |
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Prof. Luigi Broglio | Principal Investigator | National Research Council, Italy |