Correct Answer :   ISRO

The Indian Space Research Organisation (ISRO) said it successfully carried out an "extremely challenging" controlled re-entry experiment of the decommissioned orbiting Megha-Tropiques-1 (MT-1) satellite on Tuesday.

* "The satellite re-entered the Earth's atmosphere and would have disintegrated over the Pacific Ocean", the Bengaluru-headquartered national space agency said.

* The final impact region estimated is in the deep Pacific Ocean within the expected latitude and longitude boundaries, an ISRO statement said.

* The low Earth satellite was launched on October 12, 2011, as a joint satellite venture of ISRO and the French space agency, CNES for tropical weather and climate studies.

* Since August 2022, the satellite's perigee was progressively lowered through a series of 20 manoeuvres spending about 120 kg of fuel.

* Multiple manoeuvres including the final de-boost strategy were designed after taking into consideration several constraints, including visibility of the re-entry 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 constraint on thrusters.

* All manoeuvre plans were screened to ensure that there would be no post manoeuvre close approaches with other space objects, especially with the crewed space stations like International Space Stations and the Chinese Space Station, ISRO said.

* The final two de-boost burns were executed at 11:02 UTC and 12:51 UTC respectively on 7th March 2023 by firing four 11 Newton thrusters on-board the satellite for about 20 minutes each, it said.

* The final perigee was estimated to be less than 80 km indicating that the satellite would enter the denser layers of the Earth's atmosphere and subsequently undergo structural disintegration. The re-entry aero-thermal flux analysis confirmed that there would be no surviving large debris fragments.

* The entire sequence of events was carried out from the Mission Operations Complex in ISTRAC (ISRO Telemetry, Tracking and Command Network), Bengaluru.

* An uninhabited area in the Pacific Ocean between 5S to 14S latitude and 119W to 100W longitude was identified as the targeted re-entry zone for MT1, weighing about 1000 kg, ISRO said earlier this week.

* About 125 kg on-board fuel remained unutilised at its end-of-mission that could pose risks for accidental break-up, an ISRO statement had noted..

Source : Business Standard