Why In News?

Indian Space Research Organisation (ISRO) to launch the GISAT-1A (Geo Imaging Satellite) in the first week of September 2026.

 

What is GISAT-1A?

  • GISAT (Geo Imaging Satellite) is designed to provide frequent imaging of the Indian region.

  • GISAT-1A is also designated EOS-05 in India's Earth-observation satellite series.

  • It is a geostationary Earth-observation satellite designed for frequent observation and rapid monitoring of natural hazards.

  • GISAT-1A follows EOS-03/GISAT-1, whose 2021 launch failed because the cryogenic upper stage did not ignite.

  • The mission is planned on GSLV Mk II, India's cryogenic launch vehicle for approximately 2,200-kg-class payloads to GTO.

 

 

What is the GISAT Series?

  • GISAT-1: The first GISAT mission was launched as EOS-03 on GSLV-F10 in August 2021, but failed to reach orbit.

  • Failure Cause: ISRO reported that the Cryogenic Upper Stage failed to ignite because of a technical anomaly.

  • EOS-05: GISAT-1A/EOS-05 is the follow-on mission intended to restore and strengthen the geo-imaging capability.



What are the Main Objectives?

  • Continuous Observation: GISAT-1A aims to provide repeated observation of the Indian subcontinent from geostationary orbit.

  • High Temporal Resolution: Its major advantage is frequent imaging, allowing rapidly changing events to be observed more often than conventional polar-orbit satellites.

  • Disaster Monitoring: It can strengthen monitoring of cyclones, floods, forest fires, landslides and other episodic events.

  • Agriculture: Frequent imagery can support crop monitoring, damage assessment and land-use analysis.

  • Forestry: Repeated observation can help track forest-cover changes and fire events.

  • Strategic Applications: Persistent observation can also support maritime awareness, infrastructure monitoring and strategic applications.

 

Geostationary Earth-Observation Satellite 

  • Fixed View: A geostationary satellite appears fixed over a particular longitude because it orbits at the same angular speed as Earth's rotation.

  • Continuous Coverage: It can repeatedly observe the same large geographical region without waiting for another orbital pass.

  • High Temporal Resolution: This makes it particularly useful for rapidly evolving events such as cyclones and floods.

  • Near Real-Time Support: ISRO already uses space-based observations for near-real-time disaster monitoring and decision support.

  • Polar-Orbit Difference: Polar satellites generally provide higher spatial detail and global coverage, but revisit a particular location less frequently.

  • Geostationary vs Geosynchronous: A geostationary orbit is a special geosynchronous orbit that is circular and lies over the equator.

 

 

 

 

 

Source: INDIANEXPRESS

 

 

 

PRACTICE QUESTION

Q. With reference to GISAT-1A, consider the following statements:

  1. It is designed as a geostationary Earth-observation satellite.

  2. It is also designated EOS-05.

  3. It is planned to be launched using GSLV Mk II.

  4. Its predecessor EOS-03 was successfully placed into orbit.

Which of the statements given above are correct?

A. 1 and 2 only

B. 1, 2 and 3 only

C. 2 and 4 only

D. 1, 2, 3 and 4

Answer: B

Explanation:

Statement 1 is correct: GISAT-1A is designed as a geostationary Earth-observation satellite (Geo Imaging Satellite), intended to operate from a Geostationary Orbit (GEO) to provide continuous observation of the Indian subcontinent.  

Statement 2 is correct: It is officially designated as EOS-05 under ISRO's Earth Observation Satellite nomenclature. 

Statement 3 is correct: It is planned to be launched aboard the GSLV Mk II (specifically the GSLV-F17 mission). 

Statement 4 is incorrect: Its predecessor, EOS-03 (GISAT-1), was not successfully placed into orbit; the mission failed in August 2021 due to an anomaly in the cryogenic upper stage of the GSLV-F10 launch vehicle.