PSLV-C61 Mission and EOS-09 Satellite Launch Preparations
Source:The Hindu ↗
Why It Matters
ISRO's satellite launches are a recurring theme in UPSC Prelims and Mains (GS3). This mission is particularly significant because it highlights the socio-economic applications of Earth Observation Satellites (EOS) and incorporates crucial space sustainability measures (active de-orbiting to mitigate space debris), which aligns with global concerns over the Kessler Syndrome and orbital crowding.
Summary
ISRO has commenced the countdown for the launch of the PSLV-C61 mission, which will carry the Earth Observation Satellite EOS-09. This launch marks the 63rd flight of the Polar Satellite Launch Vehicle (PSLV) and the 101st mission for ISRO. EOS-09, weighing around 1,696 kg, will be placed into a Sun Synchronous Polar Orbit (SSPO). It is designed to provide high-resolution, all-weather imaging to support socio-economic and strategic applications, including agriculture, forestry, disaster management, and national security. Notably, the mission focuses on space sustainability by utilizing Orbit Change Thrusters (OCT) to safely de-orbit the satellite at the end of its 5-year mission life, demonstrating ISRO's commitment to debris-free space operations.
Key Points
- ISRO has initiated the countdown for the PSLV-C61 mission carrying the Earth Observation Satellite EOS-09, marking PSLV's 63rd flight and ISRO's 101st mission.
- EOS-09 is a 1,696 kg all-weather imaging satellite intended for a Sun Synchronous Polar Orbit (SSPO), succeeding the RISAT and EOS-04 lineage.
- The satellite will provide vital data for agriculture, forestry monitoring, disaster management, urban planning, and national security.
- Emphasizing space sustainability, ISRO will reserve fuel to use Orbit Change Thrusters (OCT) to lower the satellite's altitude and safely de-orbit it after its 5-year mission life, ensuring a debris-free space environment.
Important Terms
PSLV-C61
The 63rd flight of India's Polar Satellite Launch Vehicle and ISRO's 101st mission, utilizing the XL configuration to deploy the EOS-09 satellite into a near-polar orbit.
UPSC context
GS Paper III (Space Tech); tests knowledge of India's launch vehicle heritage and specific mission milestones.
EOS-09
A high-resolution Earth Observation Satellite (also known as RISAT-1B) equipped with Synthetic Aperture Radar (SAR) for all-weather, day-and-night imaging for strategic and socio-economic use.
UPSC context
GS Paper III; relevant for Remote Sensing applications in agriculture, disaster management, and national security.
Sun Synchronous Polar Orbit (SSPO)
A specialized low Earth orbit (LEO) that ensures a satellite passes over any given point at the same local mean solar time, providing consistent lighting for imaging.
UPSC context
GS Paper III (Science & Tech); fundamental concept regarding orbital mechanics and Earth observation satellite placement.
Orbit Change Thrusters (OCT)
Onboard propulsion systems used to lower the altitude of a satellite or rocket stage post-mission, ensuring atmospheric re-entry to prevent the accumulation of space debris.
UPSC context
GS Paper III; tests understanding of active debris removal and responsible space operations technology.
Debris Free Space Missions (DFSM)
An ISRO policy aiming for 'zero debris' missions by 2030 through post-mission disposal, passivation of rocket stages, and adherence to international sustainability guidelines.
UPSC context
GS Paper III (Environment/Space); crucial for topics on global space governance and the Kessler Syndrome.
Synthetic Aperture Radar (SAR)
An active radar technology that 'sees' through clouds, rain, and darkness by transmitting microwave pulses, essential for continuous surveillance and disaster monitoring.
UPSC context
GS Paper III (Science & Tech); key technology for all-weather remote sensing and strategic border monitoring.
Prelims Trap
EOS-09 is a geostationary satellite providing continuous, 24/7 all-weather surveillance of the Indian landmass.
EOS-09 is placed in a Sun-Synchronous Polar Orbit (SSPO), not a geostationary orbit. SSPO ensures consistent solar illumination for high-quality imaging, unlike stationary continuous monitoring.
Static Concepts Connected
What distinguishes a Sun-Synchronous Polar Orbit (SSPO)?
- Altitude & Path: It is a Low Earth Orbit (typically 500-800 km) where the satellite passes over the poles while the Earth rotates beneath it.
- Consistent Illumination: The satellite passes over any given point on Earth's surface at the exact same local solar time, ensuring consistent lighting and shadow angles.
- Primary Use: It is the preferred orbit for Earth Observation Satellites (EOS), remote sensing, and weather mapping.
What is the Kessler Syndrome and how does ISRO mitigate space debris?
- Kessler Syndrome: A theoretical chain reaction in Low Earth Orbit where collisions between space objects generate more debris, potentially rendering specific orbits unusable.
- Post-Mission Disposal: Modern ISRO satellites use Orbit Change Thrusters (OCT) and reserve fuel to safely lower altitude and burn up in the atmosphere post-mission.
- Zero Debris Goal: India has committed to achieving 'Debris Free Space Missions' (DFSM) by 2030, reinforcing sustainability.
Cross-Topic Patterns
Space Tech + Disaster Management linkages
Data from SAR-equipped satellites like EOS-09 feeds directly into NDMA's disaster management protocols, specifically for flood mapping, cyclone impact assessment, and agricultural drought monitoring.
Space Sustainability + Global Commons diplomacy
ISRO's voluntary integration of Orbit Change Thrusters aligns with UN COPUOS guidelines on space debris mitigation, highlighting India's proactive stance in regulating space as a global common.
Expect a 2026 Prelims multi-statement question pairing ISRO's 'Zero Debris by 2030' goal with SSPO orbit characteristics and OCT technology.
Linked PYQs · 2
Linked PYQs · 2
- 2018PrelimsGS1
With reference to India's satellite launch vehicles, consider the following statements: 1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites. 2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth. 3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines. Which of the statements given above is/are correct?
- 2016MainsGS3
Discuss India's achievements in the field of Space Science and Technology. How the application of this technology has helped India in its socio-economic development?
