Topper’s Copy

GS3

Science & Technology

10 marks

“PSLV is often described as ISRO’s workhorse launch vehicle.”
Explain the design features and stage-wise functioning of PSLV that justify this description.

Student’s Answer

Evaluation by SuperKalam

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Score:

6/10

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3
6
10

Demand of the Question

  • Explain design features of PSLV that justify the "workhorse" description
  • Explain stage-wise functioning of PSLV that justify this description

What you wrote:

The polar Satellite launch vehicle (PSLV) is termed ISRO's workhorse because of its high reliability, versatility, cost effectiveness, and consistent success.

The polar Satellite launch vehicle (PSLV) is termed ISRO's workhorse because of its high reliability, versatility, cost effectiveness, and consistent success.

Suggestions to improve:

  • Could briefly contextualize with a recent milestone (e.g., PSLV's 60th successful mission in 2024 demonstrating its continued operational excellence, or its role in deploying 104 satellites in a single mission showcasing multi-payload capability).

What you wrote:

Design features that justify the term "Work horse".

1. Four-stage configuration: (solid-liquid-solid-liquid)
Alternating propulsion ensures optimal thrust control and efficiency and enhances mission flexibility.

2. Strap on Boosters.
Can be used in multiple configurations. (PSLV-CA, DL, QL, XL).
Enable payload variation from 300kg to 1750kg.

3. High Reliability:
i) over 95% success rate since its first successful flight 1994.
ii) Trusted for critical national missions (IRNSS, RISAT, Cartosat)

4. payload versatility:
i) Capable of multi-satellite deployment.
ii) supports commercial launches via NSIL.

Design features that justify the term "Work horse".

1. Four-stage configuration: (solid-liquid-solid-liquid)
Alternating propulsion ensures optimal thrust control and efficiency and enhances mission flexibility.

2. Strap on Boosters.
Can be used in multiple configurations. (PSLV-CA, DL, QL, XL).
Enable payload variation from 300kg to 1750kg.

3. High Reliability:
i) over 95% success rate since its first successful flight 1994.
ii) Trusted for critical national missions (IRNSS, RISAT, Cartosat)

4. payload versatility:
i) Capable of multi-satellite deployment.
ii) supports commercial launches via NSIL.

Suggestions to improve:

  • Can strengthen the workhorse connection by explaining how design enables quick turnaround time (e.g., modular strap-on system allows ISRO to configure PSLV variants within weeks for different mission requirements, enabling 4-6 launches annually)
  • Could add dimension about cost-effectiveness through indigenous development (e.g., use of earth-storable propellants in stages 2 and 4 reduces storage complexity and operational costs, making it economically sustainable for frequent missions)

What you wrote:

Stage Wise-Functioning of PSLV.

[DRAWING: A flowchart with a central title "Stage Wise-Functioning of PSLV" and four arrows pointing down to four columns of text.]

1st Stage2nd Stage3rd Stage4th Stage
PS1-Solid propulsionLiquid propulsionSolid propulsionLiquid propulsion
fuel: Hydroxyl-terminated polybutadienefuel: UDMH+N2O4fuel: HTPBfuel: Monomethyl hydrazine + mixed oxides of nitrogen.
function: provides initial, high thrust to lift off from the launch pad.function: provides controlled thrust.function: Boost the vehicle to near-orbital velocity.function: Fine tuning of orbit.

Stage Wise-Functioning of PSLV.

[DRAWING: A flowchart with a central title "Stage Wise-Functioning of PSLV" and four arrows pointing down to four columns of text.]

1st Stage2nd Stage3rd Stage4th Stage
PS1-Solid propulsionLiquid propulsionSolid propulsionLiquid propulsion
fuel: Hydroxyl-terminated polybutadienefuel: UDMH+N2O4fuel: HTPBfuel: Monomethyl hydrazine + mixed oxides of nitrogen.
function: provides initial, high thrust to lift off from the launch pad.function: provides controlled thrust.function: Boost the vehicle to near-orbital velocity.function: Fine tuning of orbit.

Suggestions to improve:

  • Can connect stage functioning to reliability aspect (e.g., the proven solid-liquid alternating configuration minimizes failure points as solid motors have fewer moving parts, contributing to PSLV's 95%+ success rate across 60+ missions)
  • Could explain how stage separation mechanism ensures mission flexibility (e.g., the heat shield separation after second stage allows PSLV to deploy satellites at multiple orbits in single mission, demonstrated in the record 104-satellite launch)

What you wrote:

The robust design, modular architecture, stage wise propulsion efficiency, and unmatched reliability make PSLV the most dependable launch vehicle of ISRO.

The robust design, modular architecture, stage wise propulsion efficiency, and unmatched reliability make PSLV the most dependable launch vehicle of ISRO.

Suggestions to improve:

  • Could strengthen by highlighting PSLV's evolving role (e.g., as India commercializes space launches through NSIL and New Space India initiatives, PSLV's proven track record positions it as the backbone for India's emerging private space industry and international launch service market)

You've structured the answer well with clear design features and comprehensive stage details. The tabular format is appreciated. However, the connection between these technical aspects and the "workhorse" justification could be more explicit throughout. Strengthen analytical linkages between design/functioning and reliability/versatility.

Demand of the Question

  • Explain design features of PSLV that justify the "workhorse" description
  • Explain stage-wise functioning of PSLV that justify this description

What you wrote:

The polar Satellite launch vehicle (PSLV) is termed ISRO's workhorse because of its high reliability, versatility, cost effectiveness, and consistent success.

The polar Satellite launch vehicle (PSLV) is termed ISRO's workhorse because of its high reliability, versatility, cost effectiveness, and consistent success.

Suggestions to improve:

  • Could briefly contextualize with a recent milestone (e.g., PSLV's 60th successful mission in 2024 demonstrating its continued operational excellence, or its role in deploying 104 satellites in a single mission showcasing multi-payload capability).

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