ESA goes to Venus

Almost 3 years after being selected as an project, the European Space Agency (ESA) Science Comitee adopted the EnVision mission to Venus.

Why Venus

Venus, often called Earth’s “sister planet,” shares some striking similarities with our own world, but it’s also a realm of extreme conditions that make it both fascinating and challenging to explore.

1. Similarities to Earth:
   • Size and Composition: Venus is often dubbed Earth’s twin due to its similar size, mass, and rocky composition. It’s only slightly smaller than Earth, with a diameter of about 95% that of Earth’s.
   • Gravity: Venus has a gravity about 90% of Earth’s, making it relatively close in this aspect as well.
   • Surface Features: Venus possesses features like mountains, valleys, and vast plains akin to those found on Earth. Its landscape is dominated by volcanic activity, with towering volcanoes such as Maat Mons and Maxwell Montes.
   • Atmosphere: While vastly different in composition from Earth’s, Venus’s thick atmosphere bears some resemblance in terms of pressure. The atmospheric pressure on Venus at the surface is about 92 times that of Earth’s, roughly equivalent to being nearly a kilometer underwater on Earth.
2. Extreme Conditions:
   • Runaway Greenhouse Effect: Venus suffers from a runaway greenhouse effect, making its surface temperature scorchingly hot. It averages around 462°C (863°F), hotter than the surface of Mercury despite being farther from the Sun.
   • Atmospheric Composition: Venus’s atmosphere is predominantly carbon dioxide, with clouds of sulfuric acid, creating a dense and toxic environment.
   • Surface Conditions: The surface of Venus is hostile to life as we know it, with crushing pressures and acidic conditions.
3. Former Exploration Missions:
   • Venera Missions (Soviet Union): The Venera program by the Soviet Union was the first to successfully land spacecraft on Venus. Venera 7, in 1970, became the first spacecraft to transmit data from the surface of another planet. Subsequent missions provided valuable data on Venus’s atmosphere and surface conditions.
   • Magellan (NASA): Launched in 1989, Magellan was a NASA mission that used radar to map the surface of Venus. It revealed details of Venus’s topography with unprecedented clarity, helping scientists understand its geology.
   • ESA’s Venus Express: Launched in 2005, Venus Express was the European Space Agency’s mission to study Venus’s atmosphere and climate. It provided insights into the planet’s atmospheric dynamics, including its intense winds and the mysterious phenomenon of ‘super-rotation,’ where the atmosphere rotates much faster than the surface.
   • Future Missions: There are ongoing discussions and proposals for future missions to Venus, including orbiters, landers, and even missions to study the possibility of microbial life in Venus’s atmosphere.
4. Unanswered Questions:
   • Despite numerous missions, there are still mysteries surrounding Venus, such as the nature of its volcanic activity, the exact mechanisms behind its extreme atmospheric conditions, and the possibility of active geological processes.

Studying Venus not only helps us understand the complex dynamics of planetary atmospheres but also provides insights into the potential fate of Earth if certain conditions were to change drastically.

Envision Science Mission

EnVision’s measurements hold the promise of untangling the enigmatic secrets of our neighboring furnace. By delving into the intricate details, EnVision aims to unveil the profound influence of volcanoes, plate tectonics, and asteroid impacts on the Venusian terrain, shedding light on the planet’s present-day geological vigor. Furthermore, the mission endeavors to peer beneath the surface, gathering vital insights into the composition, structure, and dimensions of Venus’s core, mantle, and crust. Lastly, EnVision will scrutinize the atmospheric dynamics, unraveling the interplay between weather patterns and geological phenomena, offering a comprehensive understanding of Venus’s climatic intricacies.

Launch Date

While the mission is adopted in will be planed, we are far away from launch. ESA expects the launch to happen on an Ariane 6 by the year of 2031

Who works on Envision

EnVision is an ESA-led mission in partnership with NASA. NASA is expected to provide the VenSAR (Synthetic Aperture Radar) instrument, as well as Deep Space Network support. The other payload instruments are contributed by ESA member states, with ASI, DLR, BelSPO, and CNES respectively leading the procurement of the Subsurface Sounding Radar (SRS) and the VenSpec-M, VenSpec-H and VenSpec-U spectrometers. The radio science experiment is led by France with contributions by Germany.