SSC CGL 2025 Tier-II · Paper-I, 19 January 2026 · General Awareness · Question 10 of 150

We transcribed this text from the pictures of a candidate's response sheet for this paper; the answer is the key SSC marked with a green tick on that sheet. Solution last reviewed 11 September 2026.

Where this paper and its answers come from

SSC does not publish CGL question papers or a public answer key. This paper reaches us as a candidate's response sheet saved as pictures, so we transcribed the text from those pictures, and a second reader checked every question against them; where the layout carries meaning, we show the picture too. Each answer is the key SSC marked with a green tick on that sheet. SSC released a tentative key for challenge and later its final one, both only to candidates behind a login, and the sheet does not say which of the two it carries. UnlockIAS wrote the solutions.

Which of the following correctly describes the NISAR mission?

(a)ISRO-only mission for X-band radar mapping
(b)NASA-only mission for ultraviolet astronomy
(c)Optical imaging mission for exoplanet detection
(d)Joint ISRO–NASA mission using L and S-band radar

Answer

Why

Correct — D. The name gives it away: NISAR is the NASA-ISRO Synthetic Aperture Radar. NASA built its L-band radar, and ISRO built the S-band radar and the satellite bus and supplied the launch.

It lifted off on GSLV-F16 from Satish Dhawan Space Centre, Sriharikota, on 30 July 2025. A joint mission with L- and S-band radar → option (d).

Why the others are wrong

(a)
ISRO-only mission for X-band radar mapping — Not ISRO-only: NASA supplied the L-band radar. And NISAR's radars work in the L and S bands, not X-band.
(b)
NASA-only mission for ultraviolet astronomy — Not NASA-only, and it looks down, not out. NISAR is an Earth-observation radar satellite, not a telescope for ultraviolet astronomy.
(c)
Optical imaging mission for exoplanet detection — NISAR images with radar, not optical cameras, and it studies Earth, not planets around other stars. Radar also works through cloud and at night.

Concept

A synthetic aperture radar sends microwave pulses to the ground and records the echoes. Because it makes its own signal, it can image Earth by day or night and through cloud.

NISAR carries two such radars: NASA's L-band (24 cm wavelength) and ISRO's S-band (9.4 cm).

Together they map Earth's land and ice to track ecosystem disturbance, ice-sheet collapse and hazards such as earthquakes, volcanoes and landslides.

Each wrong option breaks one of the two things the keyed option asserts: who built it (ISRO-only, NASA-only) or how it sees (X-band, ultraviolet, optical).

Key facts

NISAR stands for NASA-ISRO Synthetic Aperture Radar.
NASA provided the L-band radar. ISRO provided the S-band radar, the satellite bus and the launch.
NISAR was launched on 30 July 2025 aboard GSLV-F16 from Satish Dhawan Space Centre.
It flies in a Sun-synchronous orbit at about 747 km.

Study next

Microwave bands in remote sensing: L, S, C and XISRO's radar imaging satellites (the RISAT series)ISRO's launch vehicles: PSLV, GSLV and LVM3

Common traps

Missing the clue in the acronym: the N and I of NISAR are NASA and ISRO.
Treating radar bands as optical imaging. L and S are microwave bands.

19 Jan 2026, 11:00 AM, GA Q.22 also tests recent space science, pairing NASA's SPHEREx telescope with the MACE telescope at Hanle, Ladakh.

Related PYQs

No directly related past PYQ was found.

Topic: General Policy — all 225 SSC CGL questions on it, every solved shift.