Chennai, Oct 8 (UNI) The Indian Space Agency on Tuesday announced that it has achieved a significant milestone, when the Upper Stage of PSLV-C37, which launched a record 104 Satellites
in a single mission, has re-entered the Earth's atmosphere within eight years.
The Upper Stage of ISRO's workhorse launch vehicle, PSLV-C37, launched on February 15, 2017 with Cartosat-2D as the main payload along with another 103 satellites as co-passengers, re-entered the Earth's atmosphere on October six.
The co-passenger satellites included INS-1A, INS- 1B, Al-Farabi 1, BGUSAT, DIDO-2, Nayif 1, PEASS, 88 Flock-3p satellites, and 8 Lemur-2 satellites.
PSLV-C37 created history as the first mission to launch 104 satellites with a single vehicle.
In an update, ISRO said after injecting the satellites and passivation, the upper stage (PS4) was left at an orbit of approximately 470x494 km size.
It was regularly tracked by USSPACECOM as an object with NORAD id 42052 and its orbital altitude slowly decayed, primarily due to atmospheric drag effects.
Since September 2024, IS4OM (ISRO System for Safe and Sustainable Space Operations Management) regularly monitored the orbital decay as part of its regular activities and predicted the re-entry into atmosphere in the first week of October 2024.
The orbit had decayed to a size of 134 x148 km, as of October six, 12:45 hrs.
As per US Space Command (USSPACECOM) prediction published in Space Track, the re-entry took place on October 6, a 15:49 hrs (+/-1 minute of uncertainty), while IS4OM prediction also showed that the re-entry would occur on October 6 at 15:48:25 hrs.
The corresponding impact point is in North Atlantic Ocean, ISRO said.
"The atmospheric re-entry of the rocket body within 8 years of its launch is fully compliant with the international debris mitigation guidelines, in particular, the guideline of Inter-Agency Space Debris coordination committee (IADC) that recommends limiting the post-mission orbital life of a defunct object in Low-Earth orbit (LEO) to 25 years", it said.
This requirement was met by properly designing passivation sequence which lowered the orbit of PS4 after the injection of the payloads.
At present, special initiatives are undertaken to ensure that the residual orbital lifetime of the PSLV upper stages is reduced to 5 years or even less by actively de-orbiting them to lower altitude orbits through engine re-starts, as in PSLV-C38, PSLV-40, PSLV-C43, PSLV-C56, and PSLV-C58 missions.
Controlled re-entry of the upper stage is also envisaged for the disposal of the upper stage in future PSLV missions.
As part of its longstanding commitment to preserve long term sustainability of outer space activities, ISRO will continue to implement proactive measures to meet the objectives of Debris Free Space Mission (DFSM) by the year 2030.
UNI GV 2015