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 tothe 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 of1.7% per decade, (2) three-stage linear model by Walterscheid, and (3) compositemodel of 2.9% per decade for solar minimum and 0.8% per decade forsolar maximum. Based on the above models for CO2 growth, effects on orbitlifetime of LEO spacecraft were estimated using a semi-analytic orbit propagationtool, LIFETIME. Orbit lifetime can increase from 5% to as large as 67%depending on initial orbit altitude, ballistic coefficient and launch date. TheInter-Agency Space Debris Coordination Committee (IADC) requires that aLEO spacecraft must reserve adequate fuel to lower the perigee at end of lifefor natural reentry due to atmosphere drag decay within 25 years. Thus, thesignificantly increased orbit lifetime will result in increased fuel requirementfor ensuring the natural decay time of an active LEO spacecraft within 25years at end of life.