The first attempts to explore the history of space with automatic probes were concentrated on this world - all with a good dose of optimism. It certainly was the most logical objective: Venus is the closest planet to us since its orbit brings it to within less than 40 000 000 kilometers from the Earth. What's more, apart from the theories regarding the presence of possible life forms, sending a probe was the only way to know something more about the surface, which is completely hidden by clouds that even the most sophisticated telescopes cannot penetrate. The first probe, Venus 1, was developed by the Soviets. It was launched in February of 1961 and radio contact was lost at 7.5 million kilometers away from the Earth. The American probe, Mariner 1, also suffered the same fate when the auxiliary rocket set the probe off its estimated trajectory and was destroyed in space for safety reasons. The first successful mission occured with Mariner 2, which was launched in August of 1962, which reached a distance of 35 000 kilometers from Venus and furnished two surprising pieces of information: the temperature on the surface reaches 400 degrees Celsius and there is no trace of a magnetic field around the planet. Nevertheless, it was the Soviets who, after various other unsuccessful missions, attained their objective with Venus 4. The probe continued to transmit data to the Earth throughout its 94-minute parachute-assisted descent. This was the first time that measuring instruments began to show the true characteristics of the planet, and it finally explains why more fragile probes were unable to do so: data confirmed in 1969 by Venus 5 and Venus 6 revealed how at only 20 kilometers from the ground, the temperature is 325 degrees Celsius and the pressure reaches 30 atmospheres. From this, the conclusions: to maintain minimum efficiency at the surface, the spacecraft should not be a delicate space probe but a real solid bathyscaph which can withstand the heat and the acid rain, including even the most delicate external parts like the radio antenna. A bathyscaph, however, that could land softly after almost neutralizing the mind-boggling cosmic speed as it traveled though space. The Soviets got down to work and finally, in 1972, they reached their objective: Venus 8 descended to the surface of the planet and was the first probe to resist the assault of the external environment for 50 minutes. During this time, the vehicle transmitted data about the surface conditions just like an astronaut would if he could stand on the surface. This confirmed the prohibitive environmental conditions on the planet but also disproved the belief by scientists that a perpetual darkness reigned over the lower levels of the atmosphere. The probe could measure the brightness of the environment, which is comparable to that of the inside of a room during a cloudy day. So, a future photographic expedition is possible: it is only necessary to protect the television camera with a more resistant material. And that great moment arrived just a little more than three years later: on October 22 and 25, 1975, the two probes Venus 9 and Venus 10 softly landed 2 000 kilometers apart, obtaining the first images of the surface of Venus.
The first attempts to explore the history of space with automatic probes were concentrated on this world - all with a good dose of optimism. It certainly was the most logical objective: Venus is the closest planet to us since its orbit brings it to within less than 40 000 000 kilometers from the Earth. What's more, apart from the theories regarding the presence of possible life forms, sending a probe was the only way to know something more about the surface, which is completely hidden by clouds that even the most sophisticated telescopes cannot penetrate. The first probe, Venus 1, was developed by the Soviets. It was launched in February of 1961 and radio contact was lost at 7.5 million kilometers away from the Earth. The American probe, Mariner 1, also suffered the same fate when the auxiliary rocket set the probe off its estimated trajectory and was destroyed in space for safety reasons. The first successful mission occured with Mariner 2, which was launched in August of 1962, which reached a distance of 35 000 kilometers from Venus and furnished two surprising pieces of information: the temperature on the surface reaches 400 degrees Celsius and there is no trace of a magnetic field around the planet. Nevertheless, it was the Soviets who, after various other unsuccessful missions, attained their objective with Venus 4. The probe continued to transmit data to the Earth throughout its 94-minute parachute-assisted descent. This was the first time that measuring instruments began to show the true characteristics of the planet, and it finally explains why more fragile probes were unable to do so: data confirmed in 1969 by Venus 5 and Venus 6 revealed how at only 20 kilometers from the ground, the temperature is 325 degrees Celsius and the pressure reaches 30 atmospheres. From this, the conclusions: to maintain minimum efficiency at the surface, the spacecraft should not be a delicate space probe but a real solid bathyscaph which can withstand the heat and the acid rain, including even the most delicate external parts like the radio antenna. A bathyscaph, however, that could land softly after almost neutralizing the mind-boggling cosmic speed as it traveled though space. The Soviets got down to work and finally, in 1972, they reached their objective: Venus 8 descended to the surface of the planet and was the first probe to resist the assault of the external environment for 50 minutes. During this time, the vehicle transmitted data about the surface conditions just like an astronaut would if he could stand on the surface. This confirmed the prohibitive environmental conditions on the planet but also disproved the belief by scientists that a perpetual darkness reigned over the lower levels of the atmosphere. The probe could measure the brightness of the environment, which is comparable to that of the inside of a room during a cloudy day. So, a future photographic expedition is possible: it is only necessary to protect the television camera with a more resistant material. And that great moment arrived just a little more than three years later: on October 22 and 25, 1975, the two probes Venus 9 and Venus 10 softly landed 2 000 kilometers apart, obtaining the first images of the surface of Venus.
