Space – GK Questions

Accelerating/decelerating reaction wheels transfers angular momentum to/from spacecraft body, enabling precise pointing without propellant expenditure.

Objects like 3753 Cruithne exhibit horseshoe orbits relative to Earth, exchanging angular momentum without collision due to 1:1 mean-motion resonance.

Chang'e 5 collected 1.731 kg of basaltic regolith from Mons Rümker in Oceanus Procellarum, youngest lunar samples (~2 Ga) filling age gap.

FRB 200428 linked to Galactic magnetar SGR 1935+2154 confirmed magnetars as FRB sources, though extragalactic FRBs may have diverse origins.

IRNSS was officially renamed NavIC ('Navigation with Indian Constellation') in April 2016 by PM Modi, emphasizing indigenous capability.

3D-printed injectors, chambers, and nozzles consolidate assemblies into single parts, cutting weight/cost; used in SpaceX SuperDraco and ISRO SCE-200 engines.

Earth trojans librate around L4 (leading) and L5 (trailing) points; 2010 TK7 (L4) and 2020 XL5 (L4) are confirmed examples.

Columbia's STS-93 mission (July 1999) deployed Chandra, the most powerful X-ray telescope, studying high-energy cosmic phenomena.

The 3.6m DOT at Devasthal, Uttarakhand, operated by ARIES, is India's largest optical telescope, supporting exoplanet and transient astronomy.

S-band (2-4 GHz) handles LEO/GEO TT&C; X-band (7-8 GHz) provides higher data rates for deep space links with reduced interference.

PSLV Orbital Experimental Module (POEM) uses depleted PS4 stage as stabilized platform hosting payloads for weeks/months post-primary mission separation.

Caloris Basin (~1,550 km diameter) formed from a giant impact early in Mercury's history, causing antipodal chaotic terrain from seismic focusing.

HLVM3 features triple-redundant avionics, enhanced fault detection, and crew escape integration, meeting stringent human-rating standards.

Giant molecular clouds (10-20 K, 10²-10⁶ particles/cm³) shield molecules from UV radiation, enabling gravitational collapse and star formation.

Neil Armstrong and David Scott docked Gemini 8 with Agena Target Vehicle on Mar 16, 1966, achieving first orbital docking despite subsequent emergency undocking.

Gaofen ('High Resolution') satellites form China's CHEOS system, providing sub-meter imagery for civilian/military applications since 2013.

Tape-spring hinges provide reliable deployment without motors/latches, reducing mass/volume for large solar arrays on GEO and deep space missions.

Ganymede possesses a dipole magnetic field generated by dynamo action in its liquid iron core, creating a mini-magnetosphere within Jupiter's magnetosphere.

Sentinel constellation provides free/open Earth observation data for environmental monitoring, managed jointly by ESA and EUMETSAT under EU Copernicus program.

Short GRBs (<2 s) originate from compact object mergers; long GRBs (>2 s) from collapsars/massive star deaths, differing in progenitors and host galaxies.