Question 94 from UPSC CSE 2016 - Science and
Technology

Question

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.

IASCODEX · Accepted Answer

Correct Option: D. Neither 1 nor 2

Strategy: Identify the extreme keyword 'only' in statement 1 and counter it with factual knowledge of other space observatories from agencies like JAXA or ESA. For statement 2, verify the provided numerical data (mass and orbit altitude) against the known specifications of Astrosat.

Key Info: **Astrosat**
- India's first dedicated multi-wavelength space observatory, launched by the Indian Space Research Organisation (ISRO).
- Launched on September 28, 2015, by PSLV-C30 from the Satish Dhawan Space Centre, Sriharikota.
- Designed to observe celestial sources across a broad range of the electromagnetic spectrum, including optical, ultraviolet (UV), and X-ray (low and high energy) regions, simultaneously. This multi-wavelength capability is a key distinguishing feature.
- Lift-off mass was approximately 1513 kg (not 2000 kg).
- Placed into a Low Earth Orbit (LEO) at an altitude of about 650 km (not 1650 km) with a low inclination (about 6 degrees to the equator).
- Payloads include: Ultraviolet Imaging Telescope (UVIT), Large Area X-ray Proportional Counter (LAXPC), Soft X-ray Telescope (SXT), Cadmium Zinc Telluride Imager (CZT Imager), and Scanning Sky Monitor (SSM).

**Global Space Observatories**
- Many countries and international agencies operate space observatories. Examples include:
  - **USA:** Hubble Space Telescope (optical/UV/near-infrared), Chandra X-ray Observatory (X-ray), Spitzer Space Telescope (infrared), NuSTAR (hard X-ray).
  - **Russia:** Spektr-R (radio telescope, often referred to as RadioAstron).
  - **Japan (JAXA):** Suzaku (X-ray, operated from 2005-2015), Hitomi (X-ray, launched 2016), XMM-Newton (ESA, with significant Japanese collaboration on some instruments).
  - **Europe (ESA):** XMM-Newton (X-ray), Gaia (astrometry), Herschel Space Observatory (infrared, retired), Planck (CMB, retired).
- Therefore, India is not the 'only' country other than USA and Russia to have launched a similar observatory, as Japan and ESA (representing European nations) have also operated advanced space observatories.

IASCODEX · Answer

Option A: 1 only

IASCODEX · Answer

Option B: 2 only

IASCODEX · Answer

Option C: Both 1 and 2