In news

The Indian Space Research Organisation (ISRO) has shortlisted 20 space-based experiment proposals for its proposed Venus orbiter mission 'Shukrayaan' to study the planet for more than four years.

Objective

• Investigation of the surface processes and shallow subsurface stratigraphy; and solar wind interaction with Venusian Ionosphere.
• Studying the structure, composition and dynamics of the atmosphere.

Why Venus?

• Venus is often described as the “twin sister” of the Earth because of the similarities in size, mass, density, bulk composition and gravity.
• It is believed that both planets share a common origin, forming at the same time out of a condensing nebulosity around 4.5 billion years ago.
• Venus is around 30 per cent closer to the Sun as compared to Earth resulting in much higher solar flux.
• Exploration of Venus began in the early 1960s.
• Venus has been explored by flyby, orbiter, a few lander missions and atmospheric probes.
• ISRO has added that although there has been a lot of progress made in exploring Venus, there still exist gaps in our basic understanding about surface/sub-surface features and processes, super rotation of Venusian atmosphere.

The Proposed Orbiter

• The payload capability of the proposed 2500-kg satellite, planned to be launched onboard GSLV Mk II rocket, is likely to be 175 kg with 500W of power.
• The proposed orbit is expected to be around 500 x 60,000 km around Venus.
• This orbit is likely to be reduced gradually, over several months to a lower apoapsis (farthest point).

Source: Indian Express