EFFECTS ON ORBIT DECAY DUE TO CO2 GROWTH IN THE ATMOSPHERE

摘要

This paper presents the results of a study of the effects on orbit decay due to the gradual increase in carbon dioxide (CO2) in the atmosphere. In this study, we assume three types of estimates of CO2 growth: (1) simple linear growth of 1.7% per decade, (2) three-stage linear model by Walterscheid, and (3) composite model of 2.9% per decade for solar minimum and 0.8% per decade for solar maximum. Based on the above models for CO2 growth, effects on orbit lifetime of LEO spacecraft were estimated using a semi-analytic orbit propagation tool, LIFETIME. Orbit lifetime can increase from 5% to as large as 67% depending on initial orbit altitude, ballistic coefficient and launch date. The Inter-Agency Space Debris Coordination Committee (IADC) requires that a LEO spacecraft must reserve adequate fuel to lower the perigee at end of life for natural reentry due to atmosphere drag decay within 25 years. Thus, the significantly increased orbit lifetime will result in increased fuel requirement for ensuring the natural decay time of an active LEO spacecraft within 25 years at end of life.