Mission Drishti

Source: News on Air

Context:

The launch of Mission Drishti by the Bengaluru-based startup GalaxEye represents a “Leapfrog” moment for the Indian private space sector. By launching the world’s first OptoSAR satellite, GalaxEye has solved one of the oldest problems in Earth Observation: the trade-off between the intuitive detail of a camera and the all-weather capability of a radar.

Summary

• Keywords: OptoSAR, SAR + Optical Fusion, SpaceX Falcon 9, 190 kg, All-weather imaging.
• The Innovation: It is the first satellite globally to house both Synthetic Aperture Radar (SAR) and Electro-Optical (EO) sensors on the same platform.
• The Launch: Carried by a SpaceX Falcon 9 rocket from Vandenberg, California, into a Sun-Synchronous Orbit (SSO) at 500 km.
• The Scale: It is India’s largest privately developed Earth observation satellite to date.
• The Data: Provides fused, analysis-ready imagery with a high resolution of 1.2 – 3.6 meters.

Understanding OptoSAR Technology

To appreciate Mission Drishti for UPSC (S&T) or Engineering exams, one must understand the synergy between its two “eyes”:

A. Synthetic Aperture Radar (SAR) – The “X-Ray Eye”

• Capability: SAR uses microwave signals (X-band) to create images. Because it provides its own illumination, it can “see” through clouds, smoke, and total darkness.
• Limitation: SAR images are often grainy (speckle noise) and require expert interpretation to understand textures.

B. Electro-Optical (EO) – The “Human Eye”

• Capability: High-resolution cameras (RGB, NIR, PAN) that capture the world exactly as we see it, providing rich color and intuitive detail.
• Limitation: It is useless at night or when it is cloudy—a major issue for tropical countries like India during the monsoon.

C. The OptoSAR Advantage

By mounting both on one satellite, GalaxEye provides Fused Data. Instead of a user buying two separate images and trying to overlay them (which is difficult due to different angles and times), Mission Drishti delivers a single, perfectly aligned dataset where the radar fills in the gaps left by the clouds.

Technical Specifications & Spectral Bands

The satellite operates across a wide range of the electromagnetic spectrum to maximize its utility:

Feature	Specification	Significance
Mass	190 kg	Largest private Indian EO satellite.
SAR Band	X-Band	High-frequency radar for fine detail.
Optical Bands	RGB, NIR, Coastal Blue, Red Edge	NIR/Red Edge are vital for Vegetation & Crop Health.
Resolution	1.2m – 3.6m	Precision mapping for infrastructure & defense.
Revisit Rate	Every 4 Days	Ideal for monitoring rapid changes (floods, border activity).

Key Exam Terms

• IN-SPACe: Indian National Space Promotion and Authorization Center; the single-window nodal agency for private space players in India.
• Sun-Synchronous Orbit (SSO): A type of Low Earth Orbit (LEO) where the satellite passes over any given point of the Earth’s surface at the same local solar time.
• Spectral Bands (Red Edge/NIR): Specific ranges of light used to measure the “greenness” or chlorophyll content of plants.
• Analysis-Ready Data (ARD): Satellite data that has been processed to a point where it can be used immediately for analysis without further correction.

Multiple Choice Questions (MCQs)

Q1. What is the primary technological innovation of GalaxEye’s ‘Mission Drishti’?

A) It is the first satellite to use nuclear propulsion.

B) It is the first satellite to integrate both Optical (EO) and Radar (SAR) sensors on one platform.

C) It is the first satellite to be launched from a balloon.

D) It is the first satellite designed to clean space debris.

Q2. Mission Drishti was launched using which launch vehicle?

A) ISRO PSLV-C58

B) SpaceX Falcon 9

C) NASA SLS

D) Roscosmos Soyuz

Q3. Which spectral band is used by the Synthetic Aperture Radar (SAR) sensor on Mission Drishti?

A) L-Band

B) S-Band

C) X-Band

D) C-Band

Q4. Why is the “OptoSAR” fusion particularly useful for tropical regions like India?

A) It allows the satellite to stay in a higher orbit.

B) It ensures the satellite can image the ground even through heavy monsoon clouds.

C) It makes the satellite invisible to enemy radars.

D) It reduces the weight of the satellite.

Q5. What is the revisit frequency of the Mission Drishti satellite?

A) Every 24 hours

B) Every 4 days

C) Every 15 days

D) Once a month

Answers:

Q1: B | Q2: B | Q3: C | Q4: B | Q5: B