Skylab 1 rocket, 1973-27B: Orbit determination and analysis
Abstract
The variations in inclination and eccentricity during the resonance phase of the orbit of the final-stage rocket which placed Skylab into orbit 14 May 1973 are analyzed, and values obtained for six lumped 31st-order harmonic coefficients in the geopotential. The variation in inclination before and after resonance is analyzed to determine the average atmospheric rotation rate lambda (rev/day). The average orbital accuracy in perigee height and orbital inclination is 90 m, though some orbits with Hewitt camera observations have much smaller sd (down to 10 m). As the orbit contracted under the influence of air drag, it passed slowly through the 31:2 geopotential resonance, when the track over the Earth repeats every 31 revolutions at intervals of 2 days. The observed variations in eccentricity are compared with those predicted by the (untested) theory for orbit contraction in an atmosphere with a strong (threefold) day-to-night variation in density. The comparison confirms the accuracy of the theory and of the CIRA 1972 atmospheric model.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- April 1979
- Bibcode:
- 1979STIN...8021391K
- Keywords:
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- Orbit Calculation;
- Satellite Drag;
- Skylab 1;
- Atmospheric Density;
- Earth Atmosphere;
- Eccentricity;
- Orbit Decay;
- Rotation;
- Astrodynamics