The Indian Space Research Organization (ISRO) brought down the decommissioned weather satellite Megha-Tropics-1 in a controlled manner and burned it in the atmosphere on Tuesday.
ISRO conducted a series of 20 maneuvers to gradually lower the satellite’s orbit from August 2022, consuming 120 kg of fuel that remained unused at the end of the mission’s life.
After two final maneuvers Tuesday evening — firing four onboard thrusters for about 20 minutes — the satellite entered the dense atmosphere and disintegrated over the Pacific Ocean.
Large satellites can survive re-entry through the atmosphere and the debris shower is brought down in a controlled manner so that it does not affect humans.
Megha-Tropiques-1 was developed as a joint mission of India and France to study the water cycle and energy exchange of the tropics. Like many others developed by ISRO, the satellite has operated for more than a decade, providing valuable data for climate models. The 1,000 kg satellite was launched in 2011 with a mission life of three years.
The space agency said the de-boost maneuvers were planned considering a number of constraints, such as reentry visibility from the ground station, ground effects on the target area, and maximum thrust and maximum firing duration of the thrusters.
“All maneuver plans were screened to ensure that there would be no close approach after a maneuver with other space objects, particularly crewed space stations such as the International Space Station and the Chinese Space Station,” the space agency said in a release.
The space agency said satellites like Megh-Tropix-1 were not designed for such controlled re-entry after life, making it challenging. Further complicating matters was that the satellite was sitting in a longer and lower orbit than intended, meaning that several systems lost redundancy and their performance decreased.
“Innovative action plans were implemented by operations … teams across ISRO centers, who worked in coordination to address these challenges.”
“In recent years, ISRO has taken proactive steps to improve compliance levels with internationally accepted guidelines on space debris mitigation,” the space agency added. This will ensure that low Earth orbit, where most satellites are deployed, is not overcrowded and the satellites are disposed of safely.
The space agency said UN and Inter-Agency Space Debris Coordination Committee (IADC) guidelines recommend that satellites can be deorbited – either by controlled entry into a safe impact zone, as was attempted by ISRO with Megh-Tropix-1, or by bringing it down. . To reduce the orbital lifetime – the time it would take for a satellite to descend from a given orbit on its own – to less than 25 years.
It is also recommended that stored fuel be removed from the spacecraft to prevent the satellite from breaking up in space and creating more debris.
In the case of Megha-Tropics-1, an 867 km orbit with a 20-degree inclination means an orbital lifetime of over 100 years. and more than 120 kg of fuel remained, which was estimated to be sufficient for a fully controlled atmospheric re-entry.
The space agency said, “MT1’s re-entry test is undertaken as part of the ongoing effort as this satellite, with sufficient remaining fuel, presents a unique opportunity to test relevant procedures and understand subsequent operational nuances. Mission disposal by direct re-entry into Earth’s atmosphere.”
(TagsToTranslate) Indian Space Research Organization
