GSLV D5, GSAT 14, Cryogenic Technology and ISRO | Science & Technology for UPSC CSE PDF Download

Introduction

• Rockets and satellites are distinct entities in space exploration.
• Rockets, or launch vehicles, are used to launch satellites into orbit.
• Examples of launch vehicles include PSLV and GSLV, while satellites include GSAT, INSAT, IRS, etc.

GSLV D5 - A Special Launch

• GSLV D5 is a rocket (launch vehicle) used to launch the GSAT 14 satellite.
• It marked India's first successful satellite launch using an indigenous cryogenic engine.
• Previously, Russian technology was used for cryogenic engines in GSLV missions.
• GSLV is a three-stage launch vehicle, featuring solid, liquid, and cryogenic stages.
• Its primary purpose is to inject 2-ton class communication satellites into Geosynchronous Transfer Orbit (GTO).

Propellants Used

• Stage 1 (Strap-Ons): UH25 & N2O4.
• Stage 1 (Core Stage): HTPB.
• Stage 2: UH25 & N2O4.
• Stage 3 (Cryogenic): LH2 & LOX.

Cryogenic propellants used in this mission: Liquid oxygen at -183°C and liquid hydrogen at -253°C.
HTPB: Hydroxyl Terminated Poly Butadiene, LH2: Liquid Hydrogen, LOX: Liquid Oxygen.
N2O4: Nitrogen Tetroxide, UH25: Unsymmetrical Dimethyl Hydrazine + 25% Hydrazine Hydrate.

The Cryogenic Engine (CE-7.5)

• India's indigenous cryogenic engine, CE-7.5, powers the upper stage of GSLV.
• Developed as part of the Cryogenic Upper Stage Project (CUSP), it replaces the KVD-1 (RD-56) engine.
• Advantages: More efficient and provides higher thrust per kilogram of propellant compared to solid and earth-storable liquid propellants.
• Offers a higher specific impulse, making it more efficient.
• Complex due to low-temperature propellant use and associated thermal and structural challenges.

GSLV Variants

• Two main variants: GSLV Mk.I and GSLV Mk.II.
• GSLV Mk.II uses the Indian CE-7.5 cryogenic engine and can launch 2500 kg into GTO.
• Previous GSLV vehicles (GSLV Mk.I) used Russian cryogenic engines.
• GSLV Mk.I had three sub-variants: GSLV Mk.I (a), GSLV Mk.I (b), and GSLV Mk.I (c).

GSAT 14 - The Satellite

• GSAT-14 is a 1,982-kg communication satellite.
• It replaces the GSAT-3 satellite launched in 2004.
• Launched by GSLV D5 with an Indian-built cryogenic engine on the third stage.
• After reaching GTO, GSAT-14 uses its own propulsion system to reach a geostationary orbit at 74° East longitude.
• Provides satellite-based communication services, including tele-education and telemedicine.
• Equipped with six Ku-band and six Extended C-band transponders for nationwide coverage.
• Carries two Ka-band beacons for weather-related Ka-band satellite communication research.
• Powered by two solar arrays generating 2,600 watts of power.

PSLV vs. GSLV

• PSLV has a track record of 25 consecutive successful launches, primarily for lower Earth orbits.
• GSLV is designed for launching heavier satellites into geosynchronous orbits.
• PSLV can carry up to 2 tons to a low Earth orbit.
• GSLV struggled with eight launches, resulting in three successful, four failed, and one partial failure.

Perigee and Apogee

• Perigee is the nearest point to Earth, while apogee is the farthest point in a satellite's orbit.
• GSAT-14 was injected into GTO with a perigee of 175 km and an apogee of 35,945 km, with an inclination of 19.3 degrees.

Targeted Orbit of GSLV-D5

• Perigee: 180 ± 5 km.
• Apogee: 35,975 ± 675 km.
• Inclination: 19.3 ± 0.1 degrees.