Megha-Tropiques-1 mission: Here's why Isro is crashing this satellite today

Megha-Tropiques-1 (MT1) mission will be terminated by the Indian Space Research Organisationon (Isro) on Tuesday.  The satellite will be intentionally crashed into the Earth's atmosphere. The MT1 mission was launched into the Low Earth Orbit (LEO) in 2011 in collaboration with the French space agency, CNES. For more than a decade, the mission delivered critical data on tropical weather and climate change. 

The MT1 was originally meant to function as a three-year mission, but it was given an extension due to its continued provision of valuable data, supporting regional and global climate models until 2021. 

Isro initiated the process in August 2022 by conducting orbit maneuvers to progressively lower MT1's orbit. The satellite crash is scheduled to occur between 4:30-7:30 pm on Tuesday. Isro has designated an uninhabited area of the Pacific Ocean as a targeted re-entry zone.

MT1 focused on Earth's tropical belt, a region responsible for transporting the Sun's excess energy to other regions through the motion of the atmosphere and oceans. This energy budget has a significant impact on Earth and thus makes it an important area for scientists to study.

Why is Isro crashing MT1?

The decision to crash MT1 is in line with the guidelines of the United Nations Inter-Agency Space Debris Coordination Committee (UNIADC) which mandates that satellites be deorbited at the end of their mission life. 

According to the UNIADC guidelines the satellite should be deorbited through a controlled re-entry into a safe impact zone, or by bringing it to an orbit where the orbital lifetime is less than 25 years.

Such satellites, if left in their current orbit, would continue to decay for more than 100 years. MT1 weighs 1,000 kg and carries approximately 125 kg of onboard fuel. This poses risks of an accidental break-up. To avoid such accidents, Isro has decided to de-orbit the satellite.