Editing Venera (section)

===Venera 3 to 6===
{{Main|Venera 3|Venera 4|Venera 5|Venera 6}}

The Venera 3 to 6 probes were similar. Weighing approximately one ton, and launched by the [[Molniya (rocket)|Molniya]]-type booster rocket, they included a cruise "bus" and a spherical atmospheric entry probe. The probes were optimised for atmospheric measurements, but not equipped with any special landing apparatus. Although it was hoped they would reach the surface still functioning, the first probes failed almost immediately, thereby disabling data transmission to Earth.

[[Venera 3]] became the first human-made object to impact another planet's surface as it crash-landed on 1 March 1966. However, as the spacecraft's data probes had failed upon atmospheric penetration, no data from within the Venusian atmosphere were retrieved from the mission.

On 18 October 1967, [[Venera 4]] became the first spacecraft to measure the atmosphere of another planet. This spacecraft first showed the major gas of Venus's atmosphere to be CO<sub>2</sub>.<ref name="fegley">{{Cite book |last=Fegley |first=B. |chapter=2.7 – Venus |date=2014 |url=https://linkinghub.elsevier.com/retrieve/pii/B9780080959757001224 |title=Treatise on Geochemistry|edition=2 |pages=127–148 |publisher=Elsevier |language=en |doi=10.1016/b978-0-08-095975-7.00122-4 |isbn=978-0-08-098300-4}}</ref> While the [[Soviet Union]] initially claimed the craft reached the surface intact, re-analysis, including atmospheric [[occultation]] data from the American [[Mariner 5]] spacecraft that flew by Venus the day after its arrival, demonstrated that Venus's surface pressure was 75–100 atmospheres, much higher than Venera 4's 25 atm hull strength, and the claim was retracted.

Realizing the ships would be crushed before reaching the surface, the Soviets launched [[Venera 5]] and [[Venera 6]] as atmospheric probes. Designed to jettison nearly half their payload prior to entering the planet's atmosphere, these craft recorded 53 and 51 minutes of data, respectively, while slowly descending by parachute before their batteries failed.

Around that time it became increasingly known that Venus was unlikely to have liquid bodies of water, however the designs for the Soviet ''Venera'' probes still considered the possibility of a water landing as late as 1964.<ref name=":7">{{Cite book |last=Dozois |first=Gardner |title=Old Venus: A Collection of Stories |date=3 March 2015 |publisher=Random House Publishing Group |isbn=978-0-8041-7985-0 |editor-last=Martin |editor-first=George R. R. |language=en |chapter=Return to Venusport |editor-last2=Dozois |editor-first2=Gardner |chapter-url=https://books.google.com/books?id=oJBoBAAAQBAJ&dq=%22The+Long+Rain%22+%22All+Summer+in+a+Day%22%22+Bradbury+Venus+-wikipedia&pg=PT8}}</ref>{{rp|xiii}}