In which type of orbit does the NISAR (NASA–ISRO Synthetic Aperture Radar) satellite operate?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. Sun-synchronous Polar Orbit.
NISAR (NASA–ISRO Synthetic Aperture Radar) operates in a Sun-synchronous Polar Orbit, which allows the satellite to pass over the same part of Earth at the same local solar time. This ensures consistent lighting conditions, making radar observations more accurate for tracking changes in Earth’s surface. NISAR orbits at around 747 km altitude and will study earthquakes, landslides, ice-sheet movements, agriculture, and ecosystem changes.
Why not the other options?
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Geostationary Orbit: Too high (35,786 km) and unsuitable for high-resolution Earth observation.
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Low Earth Orbit (general): NISAR is in a specific Sun-synchronous subset, not any LEO.
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Medium Earth Orbit: Used mainly for navigation satellites, not detailed radar mapping.