Is this the first exploration of Venus?
No. Although EnVision will boast many new "firsts," a few spacecrafts have already travelled to Venus. In fact, this mission is specifically designed to complement previous understanding and answer some of the longstanding questions no other missions were able to cover. To better understand how EnVision fits in in the grand scheme of Venus exploration it is necessary to look back on previous missions and their highlights :
- 1962-1972 Mariner (US)/ Venera (URSS) series: First flybys and probe descents into the atmosphere provided the first estimates of surface pressure and temperature and started to portray a very different sister planet.
- 1975 Venera 7 through 14 (URSS): First orbit capture around Venus. Data relay for landers and specific study of the atmosphere via IR and UV spectrometers, radiometers and photopolarimeters. First landers survived for around 100 minutes, realized the first surface analysis and pictures of the surface. Analysed basalts and granite, measured surface wind speeds of a few m/s…
- 1978 Pioneer 1 (US): First mapping of the surface. Radar at 75km resolution.
- 1983 Venera 15 and 16 (URSS): Radar maps at 1-2km resolution.
- 1984 Vega 1 and 2 (URSS): Balloons (EU participation), landers and fly-by to Halley. Balloons probed the atmosphere for a couple of days
- 1989 Magellan (US): SAR mapping of 98% of the planet at 100 to 500m resolution reveals an incredible number of volcanoes, as well as rift systems, mountain belts. Crater count indicates a mean surface age of only 500 Ma. Their uniform and apparently random distribution is still puzzling.
- 2005 Venus Express (ESA): detailed study of the atmosphere, from the ionosphere to the surface. The correlation of emissivity and topography measurements points towards the discovery of hotspot volcanism. Atmospheric SO2 evolution hints at ongoing active volcanic processes. See Legacy of Venus Express for more information on this mission's scientific discoveries and the standing questions.
Is the Timing right? EnVision as an enabler of future exploration
What is the legacy of Venus Express?