VARIATIONS IN AIR DENSITY AT HEIGHTS NEAR 150KM, FROM THE ORBIT OF THE SATELLITE 1966-101G,
Abstract
The satellite 1966-101G was launched on 2 November 1966 into an orbit with an initial perigee height of 140 km. A satellite with such a low perigee usually decays within a few days, but 1966-101G was exceptionally dense and remained in orbit until 6 May 1967. Analysis of the changes in its orbital period provides a unique opportunity for studying continuously for six months the variations in air density at a height near 150 km. This paper records the results of such an analysis, applicable for the (medium) level of solar activity prevailing early in 1967. It is shown that at a height of 155 km the air density is greater by day than by night, with the maximum daytime density exceeding the minimum night-time density by a factor of 1.7: in contrast the COSPAR International Reference Atmosphere 1965 predicts that the density should be slightly greater by night than by day. It is also found that the night-time density increases as solar activity increases, and that the density scale height given by CIRA 1965 at heights near 150 km is too low, perhaps by about 20%. The paper was presented at the COSPAR Symposium in London, July 1967. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1967
- Accession Number
- AD0665751
Entities
People
- Desmond King-Hele
- Janice Hingston
Organizations
- Royal Aircraft Establishment