ABSTRACT
Chandrayaan-1 spacecraft was injected into Geostationary Transfer Orbit (GTO) on 22nd October 2008. Subsequent orbit corrections put spacecraft into its final circular polar orbit of 100 km altitude. Thermal performance of the mission is quite satisfactory.
Chandrayaan-1 X-ray Spectrometer (C1XS) instrument is one of the eleven instruments onboard spacecraft and second in its series after the first being flown in SMART-1 (ESA spacecraft) as DCIXS (Demonstration Compact Imaging X-ray Spectrometer). The instrument is basically mapping the moon using fluorescent X-ray lines below 10 keV.
An appropriate thermal design, purely based on Passive Thermal Control techniques is evolved based on a detailed developed Thermal Mathematical Model (TMM). Main challenge was to maintain the detector temperatures (at sub-zero levels), sitting in the same electronics box which has high heat dissipation and can withstand 50°C. This paper presents the details of evolved thermal design, analysis results in terms of peak temperature summary and orbital temperature variation and flight performance for two extreme conditions i.e. Noon-Midnight (NM) and Dawn-Dusk (DD) orbit.
