ISRO: INSAT-4B Successfully Decommissioned through 11 Re-orbiting manoeuvres 

Indian Space Research Organisation (ISRO) has decommissioned the INSAT-4B, an Indian communications satellite that forms part of the Indian National Satellite System on 24th January 2022 through 11 re-orbiting manoeuvres that pushed the satellite into the desired orbit mandated by the IADC space debris mitigation guidelines. 

• The finally achieved orbit is about 340km above geostationary (GEO) altitude, in perfect compliance with IADC guidelines for space debris mitigation of GEO objects.

Note:

The decommissioning of the satellite was to comply with the United Nations(UN) and the Inter-Agency Space Debris Coordination Committee (IADC) recommended space debris mitigation. 

The INSAT-4B has completed around 14 years of on-orbit operations. 

This Telecommand intensive operation was executed between the 70-74 degree East longitude region to avoid radio frequency interference with the other operational GEO satellites.

Post Mission Disposal (PMD):

The satellite underwent Post Mission Disposal (PMD) at the end of its service, followed by decommissioning as a part of the efforts of India to preserve the long term sustainability of outer space. 

This is the 21st Indian geostationary (GEO) satellite to undergo PMD.

As a part of standard practice, the required propellant for the re-orbiting was included in the initial fuel budget. 

IADC space debris mitigation guidelines:

In compliance with the IADC space debris mitigation guidelines, a GEO object, at its end-of-life, should be raised to a nearly circular orbit well above the GEO belt to prevent its orbit from coming back into the GEO protected region within 100 years of re-orbiting.

The minimum orbit raise required is 273 Km, this was achieved through the 11 re-orbiting manoeuvres executed during 17th – 23rd January 2022. 

• The finally achieved orbit: 340km above geostationary (GEO) altitude. 

About INSAT-4B:

INSAT-4B was launched on 12th March 2007 to provide DTH (Direct To Home) and other communication services. 

INSAT – 4B Spacecraft is the second in the INSAT 4 series of spacecraft and is configured with exclusive communication payloads to provide services in Ku and C frequency bands. 

INSAT -4B was co-located with INSAT- 3A at 93.5 degrees East longitude.

About Indian Space Research Organisation (ISRO):

Chairman– S Somanath
Headquarters– Bengaluru, Karnataka