Context: Indian Space Research Organisation’s (ISRO) Venus mission, Shukrayaan I may be postponed to 2031. ISRO’s Venus mission was expected to be launched in December 2024.

• Both the U.S. and the European space agencies have Venus missions planned for 2031 — VERITAS and EnVision, respectively — while China may launch around 2026 or 2027.

Shukrayaan I mission

• Shukrayaan I is ISRO’s Venus mission.

• The mission was expected to be launched in December 2024.

• Shukrayaan I will be an orbiter mission and its payloads include a high-resolution synthetic aperture radar and a ground-penetrating radar. 

• The key objective of the Shukrayaan I mission is to study Venus’s geological and volcanic activity, emissions on the ground, wind speed, cloud cover, and other planetary characteristics from an elliptical orbit.

• Optimal launch windows from earth to Venus occur once every 19 months. However, even better optimal windows, which can further reduce the amount of fuel required at lift-off, come around every eight years.

• According to experts, both NASA (VERITAS) and the European Space Agency (EnVision) have planned Venus missions for 2031.

Objectives

• Investigation of surface process and shallow subsurface stratigraphy. Until now, no prior observation of the sub-surface of Venus has been done.

• Stratigraphy is a branch of geology in which rock layers and layering are studied.

• Study of the structure, composition and dynamics of the atmosphere.

• Investigation of Solar wind interaction with Venusian ionosphere.

Significance

• It will help to learn how Earth-like planets evolve and what conditions exist on Earth-sized exoplanets (Planets that orbit a star other than our sun).

• It will help in modelling Earth’s climate and serves as a cautionary tale on how dramatically a planet’s climate can change.

A few other space missions to Venus include

• By the U.S:  Mariner series (1962-1974), Pioneer Venus 1 and Pioneer Venus 2 (1978), and Magellan in 1989.

• By Russia: Venera series of spacecraft (1967-1983), Vegas 1 and 2 in 1985

• By Japan: Akatsuki spacecraft (2015)

• By European Space Agency: Venus Express (2005)