For most of human history, the planets were distant bodies that could only be studied from afar and visited only in our imaginations. But with the opening of the Space Age, the technology to make it practical to reach these worlds was finally available. Almost immediately, groups of scientists and engineers around the world, fueled by Cold War rivalries, started programs to reach the nearest planets, Venus and Mars. In the Soviet Union, this effort was led by the design bureau known as OKB-1 (Experimental Design Bureau 1) led by the legendary aerospace engineer, Chief Designer Sergei Korolev.

After the Soviet Union’s unsuccessful attempts to launch a pair of 1M probes to Mars on October 10 and 14, 1960, all their efforts were focused on preparing for the launch of their first spacecraft to Venus, designated 1VA (for more background on the development of the 1VA and 1M missions, see “The First Mars Mission Attempts”). With the Venus launch window opening on January 15, 1961, the engineers at OKB-1 had just three months to prepare not only the 1VA spacecraft for launch but also diagnose and correct the teething problems with the new 8K78 rocket.

The 1VA Spacecraft

Like the first Soviet missions to the Moon launched in 1958 and 1959, the objective of the 1VA mission was to impact the planet Venus, although the much more likely outcome of a flyby was still useful for scientific as well as propaganda purposes. The 1VA was a cylinder 105 centimeters across that stood 203.5 centimeters tall. The interior of the main body was pressurized with nitrogen to about 1.2 atmospheres to provide a relatively benign laboratory-like environment for most of the spacecraft’s equipment. Thermal control to maintain an internal temperature of about 30° C was provided by a system of electrically driven louvers similar to that employed by Luna 3 that photographed the far side of the Moon in October 1959. Power to recharge the probe’s batteries was provided by a pair of solar panels, each with dimensions of about 1 by 1.6 meters with a total area of about two square meters. The 1VA carried a suite of instruments similar to that carried the earlier 1M probes to characterize the particle and field environment at Venus as well as during the interplanetary cruise. An infrared radiometer was included to determine the temperature of Venus.

Also carried inside the spacecraft were some commemorative pennants inside a “thermal cover” to protect the items during entry into the Venusian atmosphere. These included a disk with the Soviet coat of arms on one side and a diagram of the inner solar system on the other, placed inside of a pressurized metal globe of the Earth 7 centimeters in diameter. This globe was designed to float in case it came down in a Venusian ocean which some astronomers at the time believed could exist on our unexplored sister planet. Some sources suggest that these commemorative items would have been carried inside a primitive lander with some rudimentary sensors. While Korolev certainly wished to include landers in the first probes to Mars and Venus, it seems unlikely that any realistic provisions to reach the surface were included in the 1VA mission.

The 1VA carried three sets of antennas for communications with the Earth. An omni-directional antenna 2.4 meters long provided communications in the VHF band during the early stages of the mission. A T-shaped antenna deployed after leaving the vicinity of the Earth transmitted in the UHF band at a data rate of one bit per second. As the 1VA approached Venus, a wire-mesh umbrella-like antenna two meters in diameter would be deployed to transmit data in the UHF and SHF bands. Commands were uplinked to the spacecraft at 1.6 bits per second using a UHF band receiver. During the early stages of the mission, the 1VA would be contacted every day or two but during the three-month long interplanetary cruise the time between communication sessions was typically five days. The intervals were controlled by an onboard timer set by ground command.

The 1VA was normally spin stabilized to keep its solar panels pointed towards the Sun. However, the spacecraft could be three-axis stabilized to observe Venus or communicate with the Earth via its directional antennas using an attitude control system based on that successfully used by Luna 3. A set of Sun and star sensors along with gyroscopes were used to sense the spacecraft’s orientation with compressed nitrogen jets providing attitude control. The spacecraft also carried a propulsion module to provide a mid-course correction capability. It was powered by a KDU-414 engine developed at OKB-2 headed by Alexei Isayev. It generated two kilonewtons of thrust burning the hypergolic propellants unsymmetrical dimethyl hydrazine and nitric acid. Despite the midcourse correction capability, it was unlikely that the 1VA would actually hit Venus as intended given the rudimentary state of interplanetary navigation and the relatively imprecise knowledge of the value of the Astronomical Unit (i.e. the mean distance of the Earth from the Sun) at that time.

The launch vehicle for the 1VA, like the 1M, was the earliest version of the four-stage 8K78 rocket later known as the Molniya. The first three stages of this rocket would eventually serve as the basis of the Soyuz launch vehicle still in use today. The first two stages of the 8K78, which were based on the 8K74 ICBM (also known as the R-7A), consisted of the Blok A core surrounded by four tapered boosters designated Blok B, V, G, and D. The engines of the four boosters and core would ignite on the launch pad to generate 4,020 kilonewtons of thrust in this first version of the 8K78. After two minutes of flight, the four boosters would shut down and separate from the rising rocket. After another three minutes of flight, the Blok A core would exhaust its propellants leaving the Blok I third stage to take over. The Blok I would burn for four minutes to place the 1VA payload and its Blok L escape stage into a temporary Earth parking orbit. After a short coast in orbit to reach the optimum injection point, the Blok L escape stage would ignite to send the 1VA on its way to Venus. This early version of the 8K78 was 41.7 meters tall and had a liftoff mass of just under 306 metric tons. At the time, the 8K78 was the most powerful rocket in the world (see “The Largest Launch Vehicles Through History“).

The Launch of the 1VA

The first 1VA was shipped to the Baikonur Cosmodrome in Soviet Kazakhstan on January 1, 1961, with its 8K78 launch vehicle arriving on January 5. Just as happened with the 1M Mars spacecraft, the launch of the 1VA was delayed as a host of problems were encountered during its final assembly, testing, and integration with the launch vehicle. Design flaws, coupled with the fact that many factory tests of the 1VA spacecraft were skipped in order to get the hardware delivered in time for the limited launch window, did not help.

After weeks of delays, 1VA number 1 mounted atop of 8K78 number L1-6 was rolled out to the launch pad on the morning of February 1, 1961. Finally, in the early-morning hours of February 4, the first probe to Venus lifted off at 4:18:04 AM Moscow Time. Unlike the pair of launches of the 1M the previous October, the Blok I third stage of the 8K78 operated successfully, placing the Blok L escape stage and its 1VA payload into a parking orbit of 224 by 328 kilometers inclined 65 degrees to the equator. With a reported mass of 6,483 kilograms, this was the heaviest object placed into orbit up to this point in the Space Age.

But Earth orbit was as far as the first 1VA would travel. A power supply failure caused by a previously unrecognized design flaw in the Blok L control system prevented the stage from igniting, stranding the spacecraft in Earth orbit. Designated Tyzhuli Sputnik 4 by the Soviets (Russian for “Heavy Satellite 4”—the first three were the successful Luna probes) or unofficially as “Sputnik 7” in the West, Soviet authorities claimed that the purpose of this flight was simply to address issues with orbiting heavy payloads and that its mission was successfully completed after one orbit. Western observers were unconvinced. While rumors of a failed attempt to orbit a cosmonaut circulated widely in the European press, it was generally suspected almost from the start that this was a failed attempt to reach Venus. The orbit of Tyzhuli Sputnik 4 decayed over the coming days and finally fell to Earth on February 26. Two years later debris from 1VA number 1, including the commemorative disk, was found by a young boy near the River Baryusha in Siberia. Apparently the “thermal cover” enclosing the commemorative items was sufficient to protect them from at least the heat from an entry at orbital speeds.

The cause of the Blok L power supply failure was quickly identified and a temporary fix implemented. On February 11, 1961, 1VA number 2 mounted atop 8K78 number L1-7 was rolled out to the launch pad. The second 1VA lifted off at 3:34:35 AM Moscow Time on February 12 with only three days left in the Venus launch window. As before, the first three stages of the 8K78 operated as intended, placing Tyzhuli Sputnik 5, with a mass of 6,475 kilograms, into a parking orbit of 198 by 319 kilometers with an inclination of 65°. But unlike its predecessor, the Blok L escape stage came to life on schedule and successfully injected the 643.5-kilogram 1VA into a trajectory towards Venus. The Soviets designated this probe their second “Automated Interplanetary Station” (the first being Luna 3 launched in 1959 – see “Luna 3: Shedding Light on the “Dark Side” of the Moon“). Only years later, after more probes were launched by the Soviet Union to Venus, would this 1VA be referred to as “Venera 1”.

The Mission of Venera 1

The first communications session with Venera 1 was held later on launch day when the quickly receding probe was already 126,300 kilometers from the Earth. A second session was held on February 13 at a distance of 488,900 kilometers. Tracking showed that Venera 1 would miss Venus by 100,000 kilometers on May 19 if its course was not corrected — an excellent shot for the first successful 8K78 flight given the 270 million kilometers Venera 1 would have to travel. Data from the scientific instruments were returned providing information on the newly recognized solar wind.

But as Venera continued into interplanetary space, things began to go wrong. The thermal control system was proving to be inadequate for the task. The Sun sensor, which was not inside the pressurized spacecraft body, was overheating and as a result was not functioning properly. To get around the problem, Venera was set spinning slowly along its Sun-pointing axis to keep the solar panels illuminated. Only when the timer was tripped would the spacecraft stabilize its attitude on all three axes and orient itself to contact controllers back on the Earth. In between communication sessions the probe’s receiver along with most of the other onboard equipment was turned off. To the relief of ground controllers, the third communication session successfully took place as programmed on February 17 at a range of 1.889 million kilometers.

On February 22, when Venera 1 was 3.2 million kilometers from the Earth, controllers sent commands to the spacecraft that were apparently acknowledged, but no engineering or scientific data were returned. During the communication session scheduled five days later, Venera’s high frequency transmitter did not respond properly and transmission fadeouts were reported. A communication session scheduled for March 4 at a range of 7.5 million kilometers failed entirely. Venera 1 was never heard from again. Not only did the Soviet probe fail to operate all the way to Venus, it did not even break the communication distance record of 36.2 million kilometers set eight months earlier by the American interplanetary probe, Pioneer 5 (see “Vintage Micro: The First Interplanetary Probe”).

An investigation into the failure was immediately started. Publically, Soviet officials stated rather ominously that sabotage during assembly of the 1VA could not be excluded. It is not known if a saboteur was ever prosecuted, but engineers at OKB-1 found a much more mundane cause for the failure: a malfunction in Venera’s timer. Hoping to salvage the mission, the Soviets enlisted the help of British radio astronomer Bernard Lovell and his team at Jodrell Bank near Manchester, England. The 76-meter radiotelescope (now known as the Lovell Observatory) located there had been used to monitor the first Soviet Luna probes in 1959 and it was hoped that they might have better luck contacting Venera 1 with their much larger antenna. Unfortunately, they did not.

On May 17, as Venera approached Venus and was expected to deploy its dish antenna, the Soviet tracking station at Yevpatoria in the Crimea sent commands towards the spacecraft in a last ditch effort to activate it in time for the flyby on May 19. Again, nothing was heard by either the Soviet tracking station or Jodrell Bank. Attempts to contact Venera 1 from Jodrell Bank with the direct assistance of Soviet engineers continued until June 20, 1961, with no luck.

The Soviet Venus missions were not a total loss. While the 1VA failed to return any data from Venus, at least it was the first object successfully launched towards another planet. Engineers at OKB-1 also learned many lessons from the flight that were applied to future missions. Valuable experience was gained with the 8K78 and additional improvements were in the works to enhance the launch vehicle’s reliability and performance. Changes to interplanetary spacecraft design were also identified. The spacecraft timer was totally redesigned along with its thermal control system. In the future ,the spacecraft receiver would also be left on to allow ground controllers to contact the spacecraft even between scheduled communication sessions. These and many more improvements would be incorporated into the next generation of probes to be launched to Venus in August of 1962 (see “You Can’t Fail Unless You Try: The Soviet Venus & Mars Missions of 1962“). But this time the Soviet Union would have competition from the American Mariner spacecraft already under development.

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Related Reading

“The First Mars Mission Attempts”, Drew Ex Machina, October 10, 2015 [Post]

“You Can’t Fail Unless You Try: The Soviet Venus & Mars Missions of 1962”, Drew Ex Machina, November 1, 2017 [Post]

General References

Boris Chertok, Rockets and People Volume II: Creating a Rocket Industry (SP-2006-4110), NASA History Division, 2006

Brian Harvey, Russian Planetary Exploration: History, Development, Legacy and Prospects, Springer-Praxis, 2007

Wesley T. Huntress, Jr. and Mikail Ya. Marov, Soviet Robots in the Solar System: Mission Technologies and Discoveries, Springer-Praxis, 2011

Nicholas L. Johnson, Handbook of Soviet Lunar and Planetary Exploration, Univelt, 1979

Timothy Varfolomeyev, “The Soviet Venus Program”, Spaceflight, Vol. 35, No. 2, pp 42–43, February 1993

Timothy Varfolomeyev, “Soviet Rocketry that Conquered Space – Part 4: The Development of a Four-Stage Launcher, 1958–1960”, Spaceflight, Vol. 40, No. 1, pp 28–30, January 1998

Timothy Varfolomeyev, “Soviet Rocketry that Conquered Space – Part 5: The First Planetary Attempts, 1960–1964”, Spaceflight, Vol. 40, No. 3, pp 85–88, March 1998