I should mention that in this series I’ll only be discussing missions that were successful in returning scientific data about their target worlds. I note it here because many early Venusian probes were unsuccessful.
Venus is often considered a sister planet to Earth, given their similar sizes and compositions. It is blanketed in a thick atmosphere of carbon dioxide, nitrogen, and sulfuric acid. When Galileo pointed his telescope at Venus, he discovered that it had phases like the Moon, evidence that it orbited about the Sun and not the Earth (I myself have observed these phases). In modern times, it has been explored by radar from signals sent from Earth, as well as numerous planetary probes.
Modern Exploration of Venus:
- Mariner 2 (1962) – The first successful Venusian mission, a NASA probe that conducted a flyby. Showed that Venus had only a paltry magnetic field and identified the temperature range of the planet.
- Venera 4 (1967) – Soviet probe that descended into the atmosphere of Venus and provided in situ data on its composition. Transmission terminated before the probe made planetfall.
- Mariner 5 (1967) – NASA flyby mission, provided further data on Venus’ magnetic field and atmosphere, as well as information on interplanetary space.
- Venera 5 (1969) – Soviet lander probe that conducted a similar mission to Venera 4 but was of stronger design. Also did not continue transmitting before reaching the surface.
- Venera 6 (1969) – Soviet lander probe, essentially the same as Venera 5.
- Venera 7 (1970) – Soviet lander, successfully made planetfall on Venus while continuing to return data, particularly surface temperature.
- Venera 8 (1972) – Another successful Soviet lander. Of particular note, it used a photometer to show that Venus’ thick cloud cover ends fairly high in the atmosphere and is relatively clear for the remaining descent to the surface.
- Mariner 10 (1974) – NASA mission with Mercury as the primary target, used Venus as a gravitational slingshot and took UV pictures of the Venusian atmosphere.
- Venera 9 (1975) – Combo Soviet orbital probe and lander, both the first probe to orbit Venus and the first probe to return an image from another planet.
- Venera 10 (1975) – Very similar to Venera 9.
- Pioneer Venus 1 (1978) – NASA orbiter mission that studied Venus for over a decade with 17 on-board experiments.
- Pioneer Venus 2 (1978) – NASA descent mission, actually consisted of one large probe and three smaller probes. The probes were not expected to survive the descent, but the Day probe continued to transmit data for 45 minutes after making planetfall.
- Venera 11 (1978) – Soviet mission where the flight stage released a lander while making a flyby of Venus. Had a multitude of on-board experiments.
- Venera 12 (1978) – Essentially identical to Venera 11.
- Venera 13 (1981) – Soviet mission of similar design with Venera 11 and 12. Returned the first color image of the Venusian surface.
- Venera 14 (1981) – Essentially identical to Venera 13.
- Venera 15 (1983) – Soviet orbiter that was placed into a polar orbit of Venus. Mapped the upper atmosphere and a third of the planet surface with 1-2 km resolution.
- Venera 16 (1983) – Essentially to Venera 15.
- Vega 1 (1985) – Soviet mission that included both a lander and a helium balloon instrument package that floated in the atmosphere for tens of hours providing data on atmospheric dynamics.
- Vega 2 (1985) – Essentially identical to Vega 1.
- Magellan (1990) – NASA orbiter that mapped 98% of the surface to a resolution of 100 m and found no signs of plate tectonics. Mission lasted for four years.
- Venus Express (2006) – ESA orbiter mission equipped with seven experiments to conduct a long-term survey of the Venusian atmosphere. Ongoing.
- MESSENGER (2007) – NASA Mercury mission that made two flybys of Venus on its way, and used its instruments to observe Venus on the second of those.
- Akatsuki (2016?) – JAXA orbiter mission that failed to enter a Venusian orbit in 2010, but there are plans to attempt another entry later this decade.
- Venus Entry Probe (2013?) – Proposed ESA mission.
- Venera-D (2016?) – Proposed Russian mission with a planned orbiter that will operate similar to the Magellan mission but with a more powerful radar. A lander is also being designed.