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3MV (Zond)


Missions to Venus


Venera-72 (Kosmos-482)







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Second Zond: destination known?

Previous chapter: Mission of Kosmos-21 (3MV-1A No. 2)

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The second Zond vehicle, apparently 3MV-1A No. 4A, arrived to the launch site on November 13, or less than a week before the closing of the launch window for the mission beyond the ecliptic. (202) However the previous failure of the 8K78 (Molniya) rocket prompted the Military Industrial Commission, VPK, to form a special investigation commission on November 26 and ground the vehicle during its work. (84) p. 690

On December 4, top space officials sent a memo to the Kremlin, mentioning that one Zond vehicle had been undergoing final factory testing (presumably, at OKB-1 design bureau in Podlipki near Moscow), along with an array of other spacecraft. Possibly, they were talking about the third Zond spacecraft, as the second one had already been delivered to the Tyuratam launch site. The document requested a permission to postpone a number of missions originally scheduled for 1963 to the first or second quarters of 1964, but did not include the Zond into the list. (509)

February 19, 1964, launch

The next Soviet deep-space mission lifted off on Feb. 19, 1964, opening a large campaign of deep-space launches to Venus and to the Moon. This time, the Molniya rocket lifted off normally at 08:37:40 Moscow Time, however the launch failed yet again during the firing of the third stage (Block I). The investigation showed that a leaking B4311-O valve let super-cold oxygen to freeze kerosene in a nearby fuel line, causing an explosion. (52) The remnants of the vehicle crashed to the ground 85 kilometers north of the town of Barabinsk in Siberia.

Western radar apparently detected this launch attempt, however public sources identified it as a failed lunar probe. (185)

According to several post-Soviet sources, this mission's goal was a Venus flyby, not a flight above the ecliptic plane and a return to Earth, as it had been originally planned. (202) However, given the latest revelations about the history of the Zond project and the designation of the spacecraft, could it still have been intended to fly the original flight plan? Since it would require six months to return to Earth, it would have been too late to provide engineering help to the developers of the Venus landers, which were scheduled to lift off just a couple of months later. However neither would the original Zond mission, yet it had been launched anyway with a projected return date six months later!

Possible redesign?

A possible clue (or a further confusion) about the design and, most importantly, destination of the second Zond launch can be found in one heavily censored Soviet-era publication. It contained a 1964 document with a technical description of the Zond spacecraft. If the date of the document is accurate and not an attempt to hide the original goal of the Zond project, then it could be assumed that it describes a revised version of the Zond program that was formulated sometime after the launch of Kosmos-21 in November 1963. Obviously, the paper never mentioned the return-to-Earth scenario formulated for the Zond project during the 1962-1963 period.

According to the document, two versions of the Zond spacecraft were developed as precursors to the Mars-Venus probes, MV. Their launches would enable to further develop launch vehicles (a clear hint at the poor performance of the Molniya launcher in previous missions), as well as to test the probes themselves and conduct an extensive scientific program.

The 800-kilogram version of the Zond spacecraft would be based on the Venus-bound version of the MV probe and would fly a four-month-long mission toward Venus. Another (996-kilogram) version would rehearse Mars-bound mission and test long-range communications up to a distance of 330 million kilometers. Its flight was to last for no less than 10 months. The spacecraft would also be tasked to photograph the Earth from a distance between 100,000 and 150,000 kilometers.

Most importantly, a technical specifications table accompanying the article showed that none of the Zond vehicles would carry a detachable lander! Instead, a specialized compartment is listed and described as a movable payload section for imaging equipment and other scientific instruments. In addition, an experimental plasma engine would be a unique system onboard the Venus-bound Zond vehicle.

Both versions of the Zond spacecraft would be lighter than their respective Venus and Mars successors, but far not by the amount freed by the removal of entry capsules. (137)


Next chapter: Mission of Kosmos-27


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3MV-1A No. 4A mission at a glance (202):


3MV-1A No. 4A (Zond)

Launch vehicle

8K78M (Molniya-M) No. G115000-26

Launch date

1964 Feb. 19, 08:37:40 Moscow Time

Flight plan

Venus flyby (?)

Flight status

Failed to reach orbit


Article by Anatoly Zak; last update: April 1, 2014

Page editor: Alain Chabot; last edit: March 31, 2014

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A 3MV-1 (Mars-Venus) spacecraft configured for the mission to Venus. 3MV-4 No. 4 spacecraft was officially announced as Venera-2, 3MV-3 No. 1 as Venera-3. Copyright © 2000 Anatoly Zak


A Molniya rocket climbs to orbit.











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