June 18, 2024
On June 14, 2024, the cryogenic upper stage of the LVM3 M3/OneWeb-2 India mission re-entered the Earth’s atmosphere. The nearly 3-ton rocket body (NORAD ID 56082) was left in an orbit of 450 km altitude after injecting 36 OneWeb satellites on March 26, 2023. The upper stage was passivated by depleting excess fuel as per the standard practiceto minimise any potential risk for an accidental break-up. The re-entry was estimated to occur within a window from 14:35 UTC to 15:05 UTC, the most probable impact being at 14:55 UTC in the Indian Ocean. Only certain elements like gas bottles, nozzle, and tanks which comprise materials of very high melting points were expected to survive the aerothermal heating during the re-entry for this rocket body.
Figure 1 The final ground trace of LVM3 M3 Cryogenic Upper Stage before atmospheric re-entry and the probable impact point
The object was tracked by the Multi-object Tracking Radar (MOTR) of ISRO at Sriharikota over the orbits before the atmospheric re-entry, the tracking data was utilised in the re-entry prediction process. The re-entry of this object was continuously monitored by ISRO’s facility, ISRO System for Safe and Sustainable Space Operations Management (IS4OM), ISTRAC at Bengaluru. The LVM3-M3 rocket body was disposed of through natural orbital decay within 2 years of the orbital injection. Therefore, it complied with international guidelines such as UN space debris mitigation guidelines.
The LVM3-M3 rocket stage also complied with the directives of India's Debris Free Space Missions (DFSM) initiative which requires the space objects operating in the Low Earth Orbital region to be in orbit for less than 5 years after the end of the mission. DFSM was announced by Chairman ISRO/Secretary of DOS on April 16, 2024, during the opening plenary of the 42nd Inter-Agency Space Debris Coordination (IADC) Committee meeting in Bengaluru, India. ISRO steadfastly pursues all efforts to meet the objectives of this initiative as all Indian space actors, both governmental and non-governmental, are expected to conform to the guidelines outlined in DFSM by the year 2030.
(More about DFSM is available here ).