Launch: The Venus Orbiter Mission is scheduled to launch in March 2028 at a cost of approximately 1236 Crore Indian Rupees.
Objectives of the Venus Orbiter Mission (VOM)
The Venus Orbiter Mission will explore the planet’s atmosphere, surface, and its interaction with the Sun.
Key scientific objectives include examining dust in the Venusian atmosphere, mapping its surface topography in high resolution, studying the solar X-ray spectrum near Venus, analyzing Venusian airglow, and investigating sub-surface characteristics.
Additionally, the mission will serve as a technology demonstration for ISRO, testing aerobraking and thermal management techniques in the harsh Venusian environment.
Aero-braking is a technique that uses a planet’s atmosphere to slow down a spacecraft and adjust its orbit.
Payloads of Mission:
Sixteen Indian payloads, two Indian and international collaborative payloads( VISWAS and RAVI), and one international payload(VIRAL) have been recommended.
Importance of Studying Venus
Earth’s Evolution: Studying Venus, often called Earth’s twin due to its similar size, density and mass, can provide insights into the evolutionary paths of terrestrial planets and factors influencing habitability.
Climate Change Insights: Venus’s extreme greenhouse effect and climatic history offer valuable lessons on climate change processes that may also apply to Earth.
Atmospheric Composition and Dynamics: The planet’s thick atmosphere, primarily composed of carbon dioxide, allows scientists to explore atmospheric science and compare it with other celestial bodies.
Geological Activity: Investigating Venus’s geological features and volcanic activity enhances our understanding of the evolution of rocky planets, particularly processes like volcanism and tectonics.
Global Interest: The renewed focus on Venus by various space agencies, including ISRO, NASA, and ESA, fosters international collaboration and advances knowledge in planetary science.
Challenges for mission:
Extreme conditions: Extreme temperature and pressure can damage spacecraft components.
Corrosive Atmosphere: Sulphuric acid clouds that dominate the Venusian surface can potentially corrode the components made of steel and titanium.
Other Challenges: Harsh terrain, lack of sunlight for solar panels, technological challenges etc.
Missions To Venus
Past missions: Mariner 2(USA, 1962), Venus express(ESA), Magellan(NASA), Akatsuki (Japan) etc.
Future missions: Venus life finder mission( Rocket Lab and MIT), DAVINCI and VERITAS(NASA), EnVision (ESA)
Early missions in the 1960s and 1970s by NASA and the Soviet Union revealed Venus’s scorching surface temperature and dense atmosphere. These missions provided initial insights into the planet’s atmospheric composition, surface features, and magnetic environment.
Later missions in the 1970s and 1980s, such as Pioneer Venus and Vega, expanded our understanding of Venus’s atmosphere, including its composition, circulation, and interaction with the Sun. These missions also collected data on the planet’s surface and its geological history.
More recent missions, like Venus Express and Akatsuki, have focused on studying the planet’s atmospheric dynamics, climate evolution, and surface features. These missions have provided valuable information on the planet’s unique characteristics and its potential for habitability in the past.
However, these missions to Venus had limited and narrow spatial coverage either South-polar region or in equatorial belt. Hence it is difficult to build global maps of many phenomena, including winds, waves, and chemical abundances. Venus Orbiter Mission would provide uniform coverage of Venus, thus providing a unique global dataset for future science missions.
Successful Robotic Missions to Venus
Venus
Venus is the brightest planet in the solar system and is the third brightest object visible from the earth after the sun and the moon. In ancient literature, Venus was often referred to as the morning & evening star.
It is the brightest among planets because it has the highest albedo due to the highly reflectivesulfuric acid that covers its atmosphere. It is sometimes visible to the naked eye in broad daylight.
Venus is sometimes called Earth’s sister planet or Earth’s twin because of their similar size, mass, proximity to the Sun, bulk composition and presence of similar physical features such as high plateaus, folded mountain belts, and numerous volcanoes, etc.
It is radically different from Earth in other respects. The surface of Venus is totally obscured by a thick atmosphere composed of about 96%carbon dioxide, covered with clouds of highly reflective sulfuric acid.
It has the densest atmosphere of the four terrestrial planets. The atmospheric pressure at the planet’s surface is 92 times that of Earth, or roughly the pressure found 900 m underwater on Earth.
Venus is by far the hottest planet in the Solar System, even though Mercury is closer to the Sun. This is because of the greenhouse effect arising from high concentrations of CO2 and a thick atmosphere.
A day on Venus is equivalent to 243 earth days and lasts longer than its year (224 days). It rotates in the opposite direction (clockwise) to most other planets.
