Venera – The Soviet Missions to Venus
Forty-three years ago today, Venera 3 became the first man-made object to impact another planet’s surface. It crash-landed on the planet Venus on 1st March 1966. This was almost a decade before NASA’s first planetary landing with Viking 1.
In one of the first attempts by any space agency to explore another planet, the USSR launched a series of probes called “Venera” – the Russian word for Venus. While the U.S. space agency can claim its exploratory dominance over Mercury (with the Mariner programme) and Mars (with the Viking landers), the USSR was able to maintain a claim to have thoroughly explored the Earth’s other sister planet. It was not until the 1990’s and the Magellan probe that Venus so thoroughly explored again.
In the late 1960s, sending a probe to Venus was accomplished by the common, tried-and-test 3-step method:
- Launch the probe on top of a modified missile and hope it didn’t explode on the launchpad.
- Send the probe toward the surface of the planet at fairly high speed.
- Hope the probe transmitted data back to Earth in the few minutes between entering the atmosphere and hitting the surface.
Following nine failed attempts to do this over a five year period, Venera 3 finally earned the distinction reaching the surface. This was just the first of many. Venera 4 later became the first to transmit actual useful science data from the surface. The programme then made improvements, with pairs of atmospheric probes and Venera 7 was able to manage the first soft, controlled landing.
Venus posed the puzzle of how to deal with its hostile atmospheric and surface conditions. A combination of high surface temperatures (~450 degrees), large atmospheric pressures (90x Earth) and chemical compositions, any probe sent to Venus did not last long. Steadily the issue of survival was solved by engineers – the initial Venera spacecraft lasted a couple of minutes before ceasing to function. By the end of the 1970s, the probe survival time went up 23 with Venera 7 to almost 2 hours with Venera 12.
With these extended functional lifespans, subsequent landers and orbiter missions began analysing and transmitting data on basalt deposits, atmospheric composition, continent mapping and basic surface imaging. The Venera series of probes were brought to an end in the early 80s with the twin Vega probes, as the USSR faced increasing financial crisis.
The advances in pioneering planetary exploration were obviously overshadowed at the time, even more so in the Western world, by the Apollo lunar missions and the more public “spacerace” which was happening at the same time.
While Mars has always been the source of fantasy for science fiction writers, astronomers are generally more captivated by the brilliance of Venus. The Venera programme’s grand implications were vast, as was the data it returned for use by researchers worldwide.
Without the atmospheric data returned on the Venusian atmosphere, a basis of comparison with Earth’s own climatology would not be possible and the present speculations on our own planet’s global warming would be much much less grounded in rigour. Those watching Venus were treated to another path for an Earth-like planet, not just meteorologically but also geologically. With massive amounts of large scale volcanism and nearly untouched craters seemingly untouched by erosion, Venus offered an ideal source of data on these two features and how much an atmosphere with up to 90 times the pressure of Earth’s played a role in helping develop them.
Before the Soyuz 19-Apollo 18 joint orbital rendezvous project, the importance of gathering data on Venus was critical in fostering an initial attempt at cooperation when data from Venera 4 and Mariner 5 was shared between both the US and USSR. This helped both nations launch more successful probes to visit not just Venus but also other inner planets such as Mercury and Mars.
As it turns out, the story of Venera is not yet finished. In 2016, the Russian space agency Roskosmos will be returning to Venus with “Venera-D” – the flagship for a new generation of Venus landers and orbiters – and a new era of Venus exploration.