UPSC Prelims 2018 Question:

With reference to India's satellite launch vehicles,

consider the following statements:

1. PSLVs launch the satellite useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines.
   
   

Which of the statements given above is/are correct?

Explanation:

• Polar Satellite Launch Vehicle (PSLV) is the third generation launch vehicle of India. It is the first Indian launch vehicle to be equipped with liquid stages. Known as the workhorse of the ISRO,  PSLV was first launched in October 1994.
  
  
• The satellites in the geosynchronous orbits appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth. So, statement 2 is not correct.
  
  
• Geosynchronous Satellite Launch Vehicle (GSLV) has the capability to put a heavier payload in orbit than the Polar Satellite Launch Vehicle (PSLV). PSLV can carry satellites up to a total weight of 2000 kg into space and reach up to an altitude of 600-900 km. GSLV can carry weight up to 5,000 kg and reach up to 36,000 km. PSLV is designed mainly to deliver earth observation or remote sensing satellites, whereas GSLV has been designed for launching communication satellites. So, statement 1 is not correct.
  
  

• 'GSLV Mk III' is configured as a three stage vehicle with two solid strap-on motors (S200), one liquid core stage (L110) and a high thrust cryogenic upper stage (C25). The S200 solid motor is among the largest solid boosters in the world with 204 tonnes of solid propellant. So, statement 3 is not correct.
  
  

Therefore, option (1) is the correct answer.

Subject: Science & Technology | Space and Related Developments