With reference to ‘Astrosat’, the astronomical observatory launched by India, which of the following statements is/are correct? 1. Other than USA and Russia, India is the only country to have launched a similar observatory into space. 2. Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth. Select the correct answer using the code given below.
- (a) 1 only
- (b) 2 only
- (c) Both 1 and 2
- (d) Neither 1 nor 2 ✓ UPSC's answer
Why the answer is (d)
• AstroSat, launched by PSLV in September 2015, is India's first dedicated multi-wavelength space observatory, observing in ultraviolet, optical and X-ray bands.
• Statement 1 is wrong: besides the US and Russia, the European Space Agency and Japan have also launched space observatories.
• Statement 2 is wrong: AstroSat weighs about 1,515 kg and orbits at about 650 km, not 2,000 kg at 1,650 km.
• Hence neither 1 nor 2, option (d).
Why the other options are wrong
- (a) 1 only
- Statement 1 is wrong: ESA and Japan also have space observatories.
- (b) 2 only
- Statement 2 is wrong: about 1,515 kg at 650 km.
- (c) Both 1 and 2
- Both statements are wrong.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2016, held on 7 August 2016. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.