TSIT ■ Chennai
Thirteen years after its launch, the RISAT-2 satellite has made an uncontrolled re-entry into the Earth’s atmosphere. The re-entry was made at the predicted impact point in Indian Ocean near Jakarta on October 30, 2022, 00:06 UTC with an uncertainty of plus/minus 10 minutes, the Indian Space Research Organisation (ISRO) said today. RISAT-2 was launched on April 20, 2009 by PSLV-C12 launch vehicle in an inclined eccentric orbit of 41.2 deg
inclination with perigee altitude 400 km and Apogee of 550 km. The satellite weighed only about 300 kg. On re-entry, there were no fuel left in the satellite and hence there are no contaminations or explosion by fuel is expected. Studies confirmed that the pieces generated due to aero-thermal fragmentation would not have survived re-en
try heating and hence no fragments would have impacted on Earth, ISRO said.
The Indian System for Safe and Sustainable Space Operations Management (IS4OM) facility in ISTRAC /ISRO had been monitoring the re-entry for the lastone month with analysis being carried out by VSSC and ISTRAC teams through its in-house developed analysis software and tracking the object utilizingMulti Object Tracking Radar (MOTR) at the SDSC, Sriharikota.
MOTR tracked RISAT-2 regularly and the data were used for further analysis and Orbit determination. The orbital data available from USSPACECOM were regularly used to predict the re-entry time and impact. The re-entry predictions of RISAT-2 was made using in-house software and it showed that it can be seen that near to the re-entry epoch, prediction became better and better. The final ground trace clearly indicate that impact is in Indian Ocean. RISAT-2 is a clear example of ISRO’s capabilityto carry out spacecraft orbital operations in an efficient and optimal way. As RISAT-2 re-entered within 13.5 years, it complied with all necessary international mitigation guidelines for Space Debris, showing ISRO’s commitment towards long term sustainability of Outer Space as well.
RISAT-2 Satellite carried 30 kg fuel for an initial designed life of four years. With the proper maintenance of orbit and mission planning by the ISRO spacecraft operations team and by economical usage of fuel, RISAT-2 provided very useful payload data for 13 years. ISRO said since its injection, RISAT-2’s radarpayload services were provided for various space applications.
