G. E. Cook

• Comparison of air densities obtained from orbital decay and instruments
• Exospheric densities near solar minimum derived from the orbit of Echo 2
• Further studies of the lifetimes of satellites in large-eccentricity orbits
• The aerodynamic drag of near earth satellites
• The orbits of lunar satellites
• The semi-annual variation in air density at a height of 1100 km from 1964 to 1967
• The semi-annual variation in the upper atmosphere
• Variations in air density at heights near 500 km from 1965 to 1967
• Variations in exospheric density at heights near 1100 km, derived from satellite orbits
• Variations in exospheric density during 1967-8, as revealed by Echo 2