ISRO preps for re-entry experiment of decommissioned satellite on March 7

The Indian Space Research Organisation ISRO is preparing for a challenging experiment of controlled reentry of a decommissioned low earth orbit satellite MeghaTropiques1 MT1 into the earths atmosphere on March 7MT1 was launched on October 12 2011 as a joint satellite venture of ISRO and French space agency CNES for tropical weather and climate studiesAlthough the mission life of the satellite was originally three years the satellite continued to provide valuable data services for more than a decade supporting regional and global climate models till 2021 the Bengaluruheadquartered space agency noted in a statement on SundayUNIADC InterAgency Space Debris Coordination Committee space debris mitigation guidelines recommend deorbiting a LEO Low Earth Orbit object at its endoflife EOL preferably through controlled reentry to a safe impact zone or by bringing it to an orbit where the orbital lifetime is less than 25 years according to ISROIt is also recommended to carry out passivation of onboard energy sources to minimise the risk of any postmission accidental breakupAlso Read Lokayukta raid Krsquotaka BJP MLA still nowhere to be foundThe orbital lifetime of MT1 weighing about 1000 kilograms would have been more than 100 years in its 20 degree inclined operational orbit of 867 km altitude About 125 kg onboard fuel remained unutilised at its endofmission that could pose risks for accidental breakupThis leftover fuel was estimated to be sufficient to achieve a fullycontrolled atmospheric reentry to impact an uninhabited location in the Pacific OceanControlled reentries involve deorbiting to very low altitudes to ensure impact occurs within a targeted safe zoneUsually large satellitesrocket bodies which are likely to survive aerothermal fragmentation upon reentry are made to undergo controlled reentry to limit ground casualty risk However all such satellites are specifically designed to undergo controlled reentry at EOLMT1 was not designed for EOL operations through controlled reentry which made the entire exercise extremely challengingFurthermore the onboard constraints of the aged satellite where several systems had lost redundancy and showed degraded performance and maintaining subsystems under harsher environmental conditions at much lower than originally designed orbital altitude added to the operational complexitiesInnovative workarounds were implemented by the operations team based on the study deliberations and exchanges among the mission operations flight dynamics aerodynamics propulsion controls navigation thermal and other subsystem design teams across the ISRO centres which worked in synergy to surmount these challengesAn uninhabited area in the Pacific Ocean between 5 degrees south to 14 degrees south latitude and 119 degrees west to 100 degrees west longitude was identified as the targeted reentry zone for MT1Since August 2022 18 orbit manoeuvres were performed to progressively lower the orbit In between the deorbiting aerobraking studies at different solar panel orientations were also carried out to gain better insights into the physical process of atmospheric drag affecting the orbital decay of the satelliteThe final deboost strategy has been designed after taking into consideration several constraints including visibility of the reentry trace over ground stations ground impact within the targeted zone and allowable operating conditions of subsystems especially the maximum deliverable thrust and the maximum firing duration of the thrustersThe final two deboost burns followed by the ground impact are expected to take place between 1630 hours to 1930 hours on March 7Simulations show that no large fragments of the satellites are likely to survive the aerothermal heating during the reentryAs a responsible space agency committed to safe and sustainable operations in outer space ISRO proactively takes efforts for better compliance with the UNIADC space debris mitigation guidelines on postmission disposal of LEO objects the statement saidThe reentry experiment of MT1 has been undertaken as a part of the ongoing efforts as this satellite with sufficient leftover fuel presented a unique opportunity to test the relevant methodologies and understand the associated operational nuances of post mission disposal by direct reentry into the Earths atmosphere it was statedThis story has been sourced from a third party syndicated feed agencies Midday accepts no responsibility or liability for its dependability trustworthiness reliability and data of the text Midday managementmiddaycom reserves the sole right to alter delete or remove without notice the content in its absolute discretion for any reason whatsoever