A rocket that has launched 342 foreign satellites from 36 countries.

A rocket that held the record for the highest number of satellites sent to space on a single launch, for 4 years by launching 104 satellites in sun-synchronous orbit.

A rocket that has succeeded 50 out of 53 times.

A rocket that has launched missions to the Moon and to the Mars

AND… the rocket that leads to one of the most economic missions.

PSLV is the name of the rocket. Polar Satellite Launch Vehicle or PSLV in short, is an expendable medium-lift launch vehicle designed and operated by the Indian Space Research Organisation (ISRO). Some notable payloads launched by PSLV include India’s first lunar probe Chandrayaan-1, India’s first interplanetary mission, Mars Orbiter Mission (Mangalyaan) and India’s first space observatory, Astrosat.

PSLV is known for cost efficiency and reliability. It’s record for highest number of satellites per launch (104) was broken by SpaceX’s Falcon 9 in Transporter -1 mission when it launched 143 satellites in 2021.

PSLV-C35 on launch pad.
Photo Credits: ISRO and GOI

PSLV Advantage

The biggest advantage of PSLV is that it is capable of placing multiple payloads into orbit with multi-payload adaptors used in the payload fairing. Multiple engine restarts to achieve multiple orbits in the same mission depending on the mission requirements, have also been demonstrated successfully for the PSLV. This allowed the feat of launching 10 satellites into different orbits in 2008.

PSLV successfully launched two spacecraft – Chandrayaan-1 in 2008 and Mars Orbiter Spacecraft in 2013 – that later traveled to Moon and Mars respectively. Although the comparison is not very logical, but the cost of PSLV’s Mars Orbiter Mission was much less than the cost of making movie “The Martian”.

At 26 Million USD per launch, the vehicle provides one of the most affordable satellite launch capability in the world.

Launch footage of PSLV, carrying 104 satellites. Video Credits: DD News

Vehicle Description

The PSLV has four stages using solid and liquid propulsion systems alternately.

The first stage, one of the largest solid rocket boosters in the world, carries 138 t (136 long tons; 152 short tons) of hydroxyl-terminated polybutadiene-bound (HTPB) propellant and develops a maximum thrust of about 4,800 kN.

PSLV-C44 first stage inside Mobile Service Tower.
PSLV-C44 first stage inside Mobile Service Tower. Photo Credits: ISRO/GOI

The second stage is powered by a single Vikas engine and carries 41.5 t (40.8 long tons; 45.7 short tons) of Earth store-able liquid propellant – unsymmetrical dimethylhydrazine (UDMH) as fuel and nitrogen tetroxide (N2O4) as oxidiser

PSLV-C50 second stage with Vikas engine
PSLV-C50 second stage with Vikas engine Photo Credits: ISRO/GOI

The third stage uses 7 t (6.9 long tons; 7.7 short tons) of hydroxyl-terminated polybutadiene-based solid propellant and produces a maximum thrust of 240 kN.

Third and fourth stages of PSLV-C45
Third and fourth stages of PSLV-C45 Photo Credits: ISRO/GOI

The fourth stage is powered by regeneratively cooled twin engines, burning monomethylhydrazine (MMH) and mixed oxides of nitrogen (MON). Each pressure fed engine generates 7.4 kN thrust.

Good to know

On PSLV-C45 campaign, the fourth stage had its own power generation capability as it was augmented with an array of fixed solar cells around PS4 propellant tank. First time ever in the whole world that 4th stage of any rocket is being equipped with solar panels

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