Shukrayaan: India’s First Mission to Venus

Venus, the second planet from the Sun, is often called the sister planet of Earth because of their similar size, mass, and proximity. However, Venus is also very different from Earth in many ways, such as its scorching surface temperature, dense atmosphere, and volcanic activity.

To explore the mysteries of this fascinating world, the Indian Space Research Organisation (ISRO) is planning to launch its first mission to Venus, named Shukrayaan, which means “craft of Venus” in Sanskrit.

What is Shukrayaan?

Shukrayaan is an orbiter mission that will study the surface and atmosphere of Venus using a variety of scientific instruments. The orbiter will have a mass of about 2,500 kg and a payload capacity of about 100 kg. It will be powered by solar panels and will carry 500 W of power for the payload.

The orbiter will be launched by a GSLV Mk II rocket from the Satish Dhawan Space Centre in Sriharikota, India. The launch window is expected to be in December 2024, when Earth and Venus are aligned in a favorable position for a low-energy transfer. The orbiter will take about six months to reach Venus and will enter an elliptical orbit around the planet, with a periapsis (closest point) of 500 km and an apoapsis (farthest point) of 60,000 km.

What are the objectives of Shukrayaan?

The main objectives of Shukrayaan are to investigate the following aspects of Venus:

• Surface/subsurface stratigraphy and re-surfacing processes: The orbiter will use a sub-surface radar to penetrate the surface of Venus up to a few hundred meters and map its structure and composition. This will help to understand the geological history and evolution of Venus, as well as the presence and distribution of volcanic features, lava flows, and tectonic activity.
• Atmospheric chemistry, dynamics, and compositional variations: The orbiter will use various sensors and spectrometers to measure the temperature, pressure, density, wind, and composition of the Venusian atmosphere at different altitudes and locations. This will help to understand the atmospheric processes and phenomena, such as the greenhouse effect, cloud formation, lightning, and sulfuric acid rain, that make Venus so hostile and different from Earth.
• Solar irradiance and solar wind interaction with Venus ionosphere: The orbiter will use a magnetometer and a plasma analyzer to study the interaction of the solar radiation and the solar wind with the ionosphere of Venus, which is the upper layer of the atmosphere that is ionized by the Sun. This will help to understand the impact of the Sun on the climate and evolution of Venus, as well as the possible existence of a weak magnetic field around the planet.

What are the challenges of Shukrayaan?

Shukrayaan is a challenging mission that will face many difficulties and risks, such as:

• Launch and orbit insertion: The launch and orbit insertion of the orbiter require precise timing and accuracy, as well as a reliable rocket and spacecraft. Any deviation or malfunction could result in a failure or a loss of contact with the orbiter.
• Thermal and mechanical stress: The orbiter will have to withstand the extreme heat and pressure of the Venusian environment, which can reach up to 460 °C and 92 bar at the surface. The orbiter will also have to endure the orbital variations and maneuvers that can cause mechanical stress and vibration.
• Communication and data transmission: The orbiter will have to communicate with the Earth through a high-gain antenna that will point towards the Earth at specific intervals. The communication and data transmission will be affected by the distance, the interference, and the encryption of the signals.
• Space debris and micrometeoroids: The orbiter will have to avoid the collision with the space debris and micrometeoroids that orbit around Venus, which can damage the spacecraft and its instruments.

What are the previous and future Venus missions?

Shukrayaan is not the first mission to Venus, nor will it be the last. Several countries and agencies have sent or plan to send missions to Venus, such as:

• Mariner 2 (1962): The first successful flyby of Venus by NASA, which measured the temperature and solar wind of the planet.
• Venera 4-16 (1967-1983): A series of landers and orbiters by the Soviet Union, which performed the first landing, the first images, and the first sound recording on Venus.
• Pioneer Venus 1 and 2 (1978): An orbiter and a multiprobe by NASA, which studied the atmosphere, the surface, and the magnetic field of Venus.
• Magellan (1989-1994): An orbiter by NASA, which mapped the surface of Venus with a radar.
• Venus Express (2005-2014): An orbiter by the European Space Agency (ESA), which studied the atmosphere, the climate, and the plasma environment of Venus.
• Akatsuki (2010-present): An orbiter by the Japan Aerospace Exploration Agency (JAXA), which is observing the weather and the clouds of Venus.
• DaVinci Plus and Veritas (2028-2030): Two orbiters by NASA, which will study the atmosphere, the geology, and the history of Venus.
• EnVision (2030s): An orbiter by ESA, which will investigate the geodynamics, the volcanism, and the habitability of Venus.

Interesting facts about Venus

• Venus is the only planet in the solar system that is named after a female figure. It is named after the Roman goddess of love and beauty, who was equivalent to the Greek goddess Aphrodite.
• Venus has no natural satellites, or moons, unlike Earth, which has one, and Mars, which has two. However, some scientists have proposed that Venus may have had a moon in the past, which collided with another large object and became part of the planet.
• Venus has the longest day of any planet in the solar system. It takes 243 Earth days to complete one rotation on its axis, which is longer than its orbital period of 225 Earth days. This means that a day on Venus lasts longer than a year on Venus.
• Venus rotates in the opposite direction of most other planets, which is called retrograde rotation. This means that the Sun rises in the west and sets in the east on Venus, unlike on Earth and most other planets, where the Sun rises in the east and sets in the west.
• Venus is sometimes called Earth’s twin or sister planet, because they have similar size, mass, and density. However, they have very different environments and climates, due to their different distances from the Sun, atmospheric compositions, and geological histories.
• Venus has the highest surface temperature of any planet in the solar system, reaching up to 462 °C, which is hot enough to melt lead. This is mainly due to the greenhouse effect, caused by the thick atmosphere of carbon dioxide and sulfuric acid clouds, which trap the heat from the Sun and prevent it from escaping.

• Venus has an active surface, with more than 1,600 volcanoes, some of which are still erupting. Venus also has mountains, valleys, craters, and plains, similar to Earth. However, Venus has no plate tectonics, which means that its surface does not move and change as much as Earth’s.
• Venus has a very weak magnetic field, unlike Earth, which has a strong one. This means that Venus has less protection from the solar wind, which is a stream of charged particles from the Sun. The solar wind can strip away the atmosphere of a planet, making it less habitable.
• Venus is the brightest object in the night sky, after the Moon. It can be seen with the naked eye, and sometimes casts shadows on Earth. It is also known as the morning star and the evening star, because it appears near the horizon before sunrise and after sunset.
• Venus has been explored by many spacecraft, both from Earth and from other planets. The first spacecraft to fly by Venus was Mariner 2 in 1962, and the first to land on Venus was Venera 7 in 1970. The most recent spacecraft to orbit Venus was Akatsuki in 2015. Some future missions to Venus include DaVinci Plus and Veritas by NASA, and EnVision by ESA.

What Is GSLV Mk II

GSLV Mk II is a launch vehicle developed by the Indian Space Research Organisation (ISRO) to launch communication satellites into geosynchronous transfer orbit using a cryogenic third stage. It is a three-stage vehicle with four liquid strap-on boosters and a payload capacity of 2,500 kg to GTO. It is the largest and most powerful launch vehicle in operation by India. It has been used in 15 launches since 2001, with nine successes, four failures, and two partial failures. The latest launch of GSLV Mk II was on 29 May 2023, carrying the IRNSS-1J navigation satellite. GSLV Mk II is also known as Geosynchronous Satellite Launch Vehicle Mark II or GSLV CON.

Conclusion

Shukrayaan is an ambitious and exciting mission that will enhance our knowledge and understanding of Venus, one of the most intriguing and mysterious planets in our solar system. Shukrayaan will also demonstrate the capabilities and achievements of ISRO, which has become a leading player in the field of space exploration. Shukrayaan will be a milestone for India and for humanity, as we seek to explore the wonders and secrets of the universe.