It appears that missions to Venus are like buses, you wait years for a new one to be picked and then three come along at once. Fresh from NASA's announcement last week that the VERITAS and DAVINCI+ Venus missions have been selected, now the European Space Agency (ESA) has announced it has selected the EnVision Venus orbiter as the fifth Medium-class mission in the ESA’s Cosmic Vision plan.
EnVision will follow in the footsteps of ESA’s Venus Express further expanding our understanding of the planet by studying both its atmosphere and its internal properties.
“A new era in the exploration of our closest, yet wildly different, Solar System neighbour awaits us,” Günther Hasinger, ESA Director of Science, said in a statement. “Together with the newly announced NASA-led Venus missions, we will have an extremely comprehensive science programme at this enigmatic planet well into the next decade.”
The next step is the “Definition Phase” where the orbiter’s design and instrument will be finalized. The earliest launch opportunity is 2031, with a 15-month cruising time and 16-month orbital circularization that will place the orbiter in a quasi-polar orbit. It will work together with NASA's Discovery missions providing crucial insights on why Venus is the way it is; namely, how you get an Earth-sized planet with crushing pressure, hellish temperatures, and acid clouds.
Understanding more about Venus not only gives insights into whether it is still geologically active, once sustained oceans, or could even have hosted life, it potentially offers a glimpse into the future of Earth if it succumbs to a catastrophic greenhouse effect.
“We are thrilled to contribute to ESA’s exciting new mission to investigate Venus,” said Thomas Zurbuchen, NASA’s associate administrator for science. “EnVision leverages strengths in instrument development by both our agencies. Combined with NASA’s Discovery missions to Venus, the science community will have a powerful and synergistic set of new data to understand how Venus formed and how the surface and atmosphere changed over time.”
EnVision is expected to end up on a low-Venus orbit between 220 and 540 kilometers (137 and 335 miles) from the planet. That will take the spacecraft around Venus in just 92 minutes. Currently, there is only one mission studying Venus, the Japanese Space Agency’s Akatsuki that has been studying the Venusian atmosphere since 2015.
“EnVision benefits from collaboration with NASA, combining excellence in European and American expertise in Venus science and technology, to create this ambitious mission,” Hasinger said. “EnVision further strengthens Europe’s role in the scientific exploration of the Solar System. Our growing mission fleet will give us, and future generations, the best insights ever into how our planetary neighbourhood works, particularly relevant in an era where we are discovering more and more unique exoplanet systems.”