Venus was always a fascination for astronomers too, as in the early days of the Space Programs, we knew nothing about the planet, whether there was life there, what the conditions on the surface were, whether we could safely go there. It is after all, a bit closer to us, than Mars, and is just about the same size. In fact, it’s only about 400 miles (650km) difference in diameter!
In case I did not mention this already, we measure the distances of planets not just in miles or kilometers but in Astronomical Units or AUs. Earth is 1AU. So we have comparable distances based on the distance from the Earth to the sun. Venus is approximately .74AU. Mars is 1.34AU. Get the picture?
I also believe that there was so much media focus on the human space flight program that we did not realize how much effort was being put into missions to the inner planets. I hope you will be surprised at how much was done in the early days of the Space Programs - how many spacecraft were sent and what we found. Perhaps in these early days, what we really learned were techniques to fly to other planets, how to map them and learn how to test their composition and habilitibility.
Now Imagine the surprise and disappointment when the first spacecrafts tried to land on Venus and was immediately crushed!
Both the Russians and the Americans started to send spacecraft to Venus (and Mars) in the early 1960s. We have never stopped!
We have continued to send missions to Venus ever since.
I do not think that the following facts have been reported in the mainstream media:
° There have been more than 20 spacecraft that have been sent to Venus since the 1960s.
° We (the world) have two spacecraft orbiting now.
° Despite the cold war and the race to the moon, scientists in Russia and the US have shared information throughout.
° On Venus, we learned how to develop radar mapping techniques that are still in use today (although we have vastly improved our video skills).
Here is a video of how we mapped Venus. It’s not great quality as we did not have high-definition cameras at that time. (1990)
Here is a composite video that shows a fly over of a region of Venus called Alpha Reggio: .
Here is another showing a different area, starting at an area called Sif Mons.
Again these are fairly low quality but these were the first composite video maps of another world almost 30 years ago..
Here is a more recent HD image of the region:
A ton of more details follow. A lot of information was taken from Wikipedia, whom I thank. I have tried to simplify it as much as possible:
The first robotic space probe mission to Venus, and the first to any planet, began on February 12, 1961 with the launch of the Russian Venera 1 probe. The first craft of the otherwise highly successful Soviet Venera program, Venera 1 was intended merely to get to Venus and crash into it - we wanted to learn how to reach another planet, , but contact with the spacecraft was lost seven days into the mission. It was estimated to have passed within 100 000 km from Venus in mid-May.
The United States exploration of Venus also started badly with the loss of the Mariner 1 probe on launch. The subsequent Mariner 2 mission had greater success , and after a 109-day journey, on December 14, 1962, it became the world's first successful interplanetary mission, passing 34,833 km (21,000 miles) above the surface of Venus. Its microwave and infrared equipment revealed that while Venus's cloud tops were cool, the surface was extremely hot—at least 425 °C (800°F), ending any hopes that the planet might harbor ground-based life. Mariner 2 did not find either a magnetic field or radiation belts.
The Venera 3 probe crash-landed on Venus on March 1, 1966. It was the first man-made object to enter the atmosphere and strike the surface of another planet, though its communication system failed before it was able to return any information.
Venus's next encounter with an unmanned probe came on October 18, 1967, when Venera 4 successfully entered the atmosphere and deployed a number of science experiments.
Venera 4 showed that the surface temperature was even hotter than Mariner 2 had measured at almost 500 °C (over 900 °F and that the atmosphere was about 90 to 95% carbon dioxide. The Venusian atmosphere was considerably denser than Venera 4's designers had anticipated, and its slower than intended parachute descent meant that its batteries ran down before the probe reached the surface. After returning descent data for 93 minutes, Venera 4's last pressure reading showed an atmosphere 900 times thicker than Earth at an altitude of 24.96 km (about 15 miles).
We no longer using “Bars” to measure atmospheric pressure, and this site explains why. Instead we use a complicated formula, and if you are a math wiz, you might like this or even know it. An analogy is Scuba diving. Every 30 feet you dive, the atmospheric pressure is doubled. Dive to 90ft and the atmosphere is 3 times that of the surface. Diving into Venus showed atmospheric pressure 900 times that of Earth in the atmosphere -- not even on the surface. Venus is a very difficult place to land. We now only use Bars to measure alcohol intact in carbon-based life-forms.
Anyway, another probe arrived at Venus one day later on October 19, 1967 when Mariner 5 conducted a flyby at a distance of less than 4000 km above the cloud tops. Mariner 5 was originally built as backup for the Mars-bound Mariner 4, but when that mission was successful, the probe was refitted for a Venus mission. A suite of instruments more sensitive than those on Mariner 2, in particular its radio experiment, returned data on the composition, pressure and density of Venus's atmosphere.
Despite this period being the height of the cold war and the race to the moon, the joint Venera 4–Mariner 5 data were analyzed by a combined Soviet-American science team in a series of colloquia over the following year, in an early example of space cooperation.
Armed with the lessons and data learned from Venera 4, the Soviet Union launched the twin probes Venera 5 and Venera 6 five days apart in January 1969; they encountered Venus a day apart on May 16 and May 17 that year.
The probes were strengthened to improve their crush depth to 25 atmospheres and were equipped with smaller parachutes to achieve a faster descent. Since then-current atmospheric models of Venus suggested a surface pressure of between 75 and 100 atmospheres, neither was expected to survive to the surface. After returning atmospheric data for a little over fifty minutes, they both were crushed at altitudes of approximately 20 km before going on to strike the surface on the night side of Venus.
Surface and Atmospheric Science
Venera 7 represented a concerted effort to return data from the planet's surface, and was constructed with a reinforced descent module capable of withstanding a pressure of 9000 atmospheres. The module was pre-cooled prior to entry and equipped with a specially reefed parachute for a rapid 35-minute descent. Entering the atmosphere on December 15, 1970, the parachute is believed to have partially torn during the descent, and the probe struck the surface with a hard, yet not fatal, impact. Probably tilted onto its side, it returned a weak signal supplying temperature data for 23 minutes, the first telemetry received from the surface of another planet.
The Venera program continued with Venera 8 sending data from the surface for 50 minutes, and Venera 9 and Venera 10 sending the first images of the Venusian landscape. The two landing sites presented very different visages in the immediate vicinities of the landers: Venera 9 had landed on a 20 degree slope scattered with boulders around 30–40 cm across; Venera 10 showed basalt-like rock slabs interspersed with weathered material. These photographs are the first taken from the surface of another planet. The metal looking diamonds at the bottom of the photos are part of the landing feet of the space craft.
In the meantime, the United States had continued to send a series of Mariner spacecraft to Venus. The Mariner 10 probe on a gravitational slingshot trajectory past Venus on its way to Mercury. On February 5, 1974, Mariner 10 passed within 5790 km of Venus, returning over 4000 photographs as it did so. The images, the best then achieved, showed the planet to be almost featureless in visible light, but ultraviolet light revealed details in the clouds that had never been seen in Earth-bound observations.
The Pioneer Venus Orbiter
The American Pioneer program was a venture to send a number of similar spacecraft to the sun, to the inner and some of the outer planets. The Venus Pioneer program consisted of two separate missions. The Pioneer Venus Orbiter (Pioneer 12) was inserted into an elliptical orbit around Venus on December 4, 1978, and remained there for over thirteen years studying the atmosphere and mapping the surface with radar. The Pioneer Venus Multiprobe (Pioneer 13) released a total of five probes which entered the atmosphere on December 9, 1978, returning data on its composition, winds and heat fluxes. The Jet Propulsion Lab has a decent archive of the successes and failures of the Pioneer program. I will have more on Pioneer when we move to the outer planets. Of course, wiki is another source for Pioneer information. Here is a photo of the Venus Orbiter.
Four more Venera lander missions took place over the next four years, with Venera 11 and Venera 12 detecting Venusian electrical storms; and Venera 13 and Venera 14, landing four days apart on March 1 and March 5, 1982, returning the first color photographs of the surface. All four missions deployed parachutes for braking in the upper atmosphere, but released them at altitudes of 50 km, the dense lower atmosphere providing enough friction to allow for an unaided soft landing. Both Venera 13 and 14 analyzed soil samples with an on-board X-ray fluorescence spectrometer, and attempted to measure the compressibility of the soil with an impact probe. Venera 14, though, had the misfortune to strike its own ejected camera lens cap and its probe failed to make contact with the soil. The Venera program came to a close in October 1983 when Venera 15 and Venera 16 were placed in orbit to conduct mapping of the Venusian terrain with synthetic aperture radar.
Color image taken from the surface of Venus by the Soviet Venera 13 lander. The orange color is due to atmospheric scattering removing the blue wavelengths from the surface sunlight. In 1985 the Soviet Union took advantage of the opportunity to combine missions to Venus and Comet Halley, which passed through the inner solar system that year. En route to Halley, on June 11 and June 15, 1985 the two spacecraft of the Vega program each dropped a Venera-style probe (of which Vega 1's partially failed) and released a balloon-supported aerobot into the upper atmosphere. The balloons achieved an equilibrium altitude of around 53 km, where pressure and temperature are comparable to those at Earth's surface. They remained operational for around 46 hours, and discovered that the Venusian atmosphere was more turbulent than previously believed, and subject to high winds and powerful convection cells.
The Vega Program
The Vega program were a series of 2 sister ships, in fact, improved Venera craft, which also took advantage of the appearance of Comet Halley in 1986. Vega 1 and Vega 2 were unmanned spacecraft launched in a cooperative effort among the Soviet Union (who provided the spacecraft and launch vehicle) and Austria, Bulgaria, Hungary, the German Democratic Republic, Poland, Czechoslovakia, France, and the Federal Republic of Germany in December 1984.
They had a two-part mission to investigate Venus and also flyby Halley's Comet.
The flyby of Halley's Comet had been a late mission change in the Venera program following on from the cancellation of the US Halley mission in 1981. A later Venera mission was cancelled and the Venus part of the Vega 1 mission was reduced. Because of this, the craft was designated Vega, a contraction of "Venera" and "Gallei" (Russian words for "Venus" and "Halley", respectively). The two spacecraft were launched on December 15 and December 21, 1984, respectively. With their redesignated dual missions, the Vega probes became part of the Halley Armada, a group of Earth probes that studied Halley's Comet during its 1985/86 visit..
Vega 1 arrived at Venus on June 11, 1985, and Vega 2 on June 15, 1985, and each delivered a 1,500 kg, 240 cm diameter spherical descent unit. The units were released some days before each arrived at Venus and entered the atmosphere without active inclination changes. Each contained a lander and a balloon explorer.
The landers were identical to that of the previous five Venera missions and were to study the atmosphere and surface.
The Vega 1 lander's surface experiments were inadvertently activated at 20 km from the surface by an especially-hard wind jolt, and so failed to provide results but it's balloon was safely deployed.
The Vega 2 lander touched down at 03:00:50 UT on 15 June 1985 in eastern Aphrodite Terra. The altitude of the touchdown site was 0.1 km above the surface and it transmitted data from the surface for 56 minutes.
The helium balloons were 3.54 meters (11.6 ft) in diameter and with instruments weighed 25 kg in total. They were deployed onto the planet's dark side at approximately 50 kilometers (30 miles) from the surface in the most active layer of the Venusian cloud system. The 5 kg instrument pack was suspended in a Gondola and had enough battery power for sixty hours of operation. They were designed to measure temperature, pressure, wind speed and aerosol density. Both Vega-1 and Vega-2 balloons operated for more than 46 hrs from deployment to their final transmission.
At this altitude, pressure and temperature conditions of Venus are similar to those of Earth, though the planet's winds moved at hurricane velocity and the carbon dioxide atmosphere is laced with sulfuric acid, along with smaller concentrations of hydrochloric and hydrofluoric acid. This sounds like something out of either "The Exorcist" or my Mother-in-law.
The balloons moved swiftly across the night side of the planet into the light side, where their batteries finally ran down and contact was lost. Tracking indicated that the motion of the balloons included a surprising vertical component, revealing vertical motions of air masses that had not been detected by earlier probe missions.
After their encounters, the Vegas' motherships were redirected by Venus' gravity to intercept Comet Halley. We'll get to that later.
The United States' Magellan probe was launched on May 4, 1989, with a mission to map the surface of Venus with radar. The high-resolution images it obtained during its 4½ years of operation far surpassed all prior maps and were comparable to visible-light photographs of other planets. Magellan imaged over 98% of Venus's surface and mapped 95% of its gravity field. In 1994, at the end of its mission, Magellan was deliberately sent to its destruction into the atmosphere of Venus in an effort to quantify its density. Venus was observed by the Galileo and Cassini spacecraft during flybys on their respective missions to the outer planets, but Magellan would otherwise be the last dedicated mission to Venus for over a decade.
Current and Future Missions
The Venus Express probe was designed and built by the European Space Agency. Launched on November 9, 2005, by a Russian Soyuz-Fregat rocket procured through Starsem, it successfully assumed a polar orbit around Venus on April 11, 2006. The probe is undertaking a detailed study of the Venusian atmosphere and clouds, and will also map the planet's plasma environment and surface characteristics, particularly temperatures. Its mission is intended to last a nominal 500 Earth days, or around two Venusian years.
One of the first results emerging from Venus Express is the discovery that a huge double atmospheric vortex exists at the South pole of the planet.
NASA's MESSENGER mission to Mercury performed flybys of Venus in October 2006, and June 2007 and most recently in October 2008, in order to slow its trajectory for an eventual orbital insertion of Mercury in 2011. MESSENGER collected scientific data on both those flybys.The European Space Agency (ESA) will also launch a mission to Mercury, called BepiColombo, which will perform two flybys of Venus in August 2013 before it reaches Mercury orbit in 2019.
Future dedicated missions to Venus are planned. Japan's aerospace body JAXA is planning to launch its Venus climate orbiter, the PLANET-C, in 2010. Under its New Frontiers Program, NASA has proposed a lander mission called the Venus In-Situ Explorer to land on Venus to study surface conditions and investigate the elemental and mineralogical features of the planet. It will be equipped with a core sampler to drill into the surface to study pristine rock samples not weathered by the very harsh surface conditions of the planet.
Other proposed Venus exploration concepts include rovers, balloons, and a Venus airplane concept. All of these are designed to investigate more fully, the atmosphere about 50km (35m) above the planet, where we could possibly create habitable environments. This is not science fiction. People are really thinking about this stuff!!! See below.
Manned Venus Flyby
A manned Venus flyby mission, using Apollo program hardware, was proposed in the late 1960s.The mission was planned to launch in late October or early November 1973, and would have used a Saturn V to send three men to fly past Venus in a flight lasting approximately one year. The spacecraft would have passed approximately 5,000 kilometres from the surface of Venus about four months later. Venus flyby missions have also been proposed as part of an opposition-class Mars mission. This means a flyby of Venus, and using it’s gravitational field to accelerate the spacecraft to Mars!
Due to the extremely hostile conditions on the surface, our current technology makes it impossible to colonize the surface of Venus in the near future. However, there have been recent speculations about the possibility of developing extensive "floating cities" in the atmosphere of Venus in the future. This concept is based on the atmospheric conditions approximately fifty kilometres above the surface of the planet, where atmospheric pressures and temperatures are thought to be similar to those of Earth. In my opinion, this is incredibly dangerous -- what if these “cities” rise and/or fall in an atmosphere we know little about.
Also, this would be living in a glass bubble above a 900° volcano. We have “snapshots” of the atmosphere from the short time spacecraft have visited there, but we do not know anywhere near enough about longer term events in the Venusian atmosphere. Still, it’s fun to dream, and maybe some of you kids reading this will get turned on to the idea and think about how to do this safely.
Proposals suggest that manned exploration can be conducted from aerostat vehicles, followed in the longer term by permanent settlements. The existence of dangerous quantities of volatile acids at these heights, however, precludes any short term settlements.
Another big idea is that we could build a shield to “protect” Venus from the sun. Then over time, its atmospheric heat would be radiated into space resulting in the majority of the thick atmosphere eventually raining out onto the surface leaving a planet better suited for terraforming and eventual settlement. There’s another job possibility :)