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Atmospheric Drag Experiment

NSSDCA ID: 1964-084A-01

Mission Name: San Marco 1
Principal Investigator:Prof. Luigi Broglio


The Atmospheric Drag Experiment made use of measurements of the drag deceleration experienced by the outer shell with reference to the inner part of the satellite, protected from drag effects and not rigidly connected to the shell. The shell was coupled to the inner satellite by a strain gauge consisting of three orthogonal springs to measure the force on the satellite in all directions. The experiment could be switched between a low-force and a high-force scale. The low-force scale could measure from 0 to 2.5 grams, and the high-force scale from 0 to 25 grams. When a force greater than 2.5 grams was detected, the experiment automatically switched to the high-force scale. The three axes were vectorially summed and fed into a fourth channel. All three balances could be individually zeroed by ground command when the spacecraft was out of the Earth's atmosphere at apogee. The spherical shape of the satellite provided aerodynamic isotropy, simplifying the interpretation of the results. At launch, the gauges were protected by a pneumatic caging system, which connected the external shell to the inner structure.

Alternate Names

  • SanMarco1/Atmosphere

Facts in Brief

Mass: 113.4 kg
Power (avg): 2 W

Funding Agency

  • Unknown (Italy)


  • Space Physics: Thermospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Prof. Luigi BroglioPrincipal InvestigatorNational Research Council, Italy
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