[FPSPACE] Zond 2 - did it have a lander for Mars?

[Paolo Ulivi]

while Zond 2 is understood to have been a flyby probe, there are still a 
few details about it that are muddy. In particular, it is not clear in 
particular how long were contacts maintained.
- Siddiqi's "Deep Space Chronicle", summarizing Russian sources, seems 
to imply that contact was lost during the second half of December 1964, 
i.e. a few weeks after launch.
- Sven Grahn's history of Jodrell Bank space tracking activities 
(http://www.svengrahn.pp.se/trackind/jodrell/jodrole2.htm#Zond12) states 
that "Contact [of Jodrell Bank] with the probe was irregular and  
uncertain"
- Flight International (referenced by Sven), however, stated that 
contacts were made by Jodrell Bank in January and February 1965.
I have been able to find, however, a letter by Jodrell Bank's Bernard 
Lovell published in "Science" (vol. 157, pages 487-488) under the title 
"Soviet Practices in Space", which reveals a lot of interesting details 
about Zond 2. Unfortunately, I found the letter too late for inclusion 
in my "Robotic Exploration of the Solar System - part 1" book!
In it, Lovell states:
"The probe was located at Jodrell Bank on 2 December 1964, the day after 
it was launched. Although the Soviet scientists failed to answer a 
number of inquiries, contact was maintained in spite of the irregular 
and intermittent nature of the transmissions. During January 1965 
contact was maintained on a number of successive days. This daily 
sequence ceased before the end of the month and in February the 
transmissions appeared to be on a weekly timetable. Contact became 
increasingly difficult, not because of weak signals, but because the 
probe's transmissions occurred even less frequently in March and April. 
Our last definite contact with Zond 2 was on 7 April 1965."
Moreover, Lovell continued
"On 17 February 1965 Keldysh and some of his colleagues visited Jodrell 
Bank (they were in the U.K. at the invitation of the Royal Society). We 
replayed the Zond 2 signals to Keldysh and referred to the orbital 
computations made by one of my colleagues on the basis of our tracking 
data that Zond-2 was on a collision course with Mars [...] Keldysh said 
that "the original trouble with the probe had been overcome but another 
difficulty had occurred which it was hoped to correct." He also said 
that the probe would "pass within 1500 km of the planet."
With respect to these statements we assumed that the "original trouble" 
was that with the power supplies referred to in the Tass communiques of 
December 1964. We have no idea what the other difficulty was, but 
clearly it led to the cessation of signals some time in April 1965."
"Search for Zond 2 signals, around the predicted date of close approach 
6 August, from 5 to 7 August was made with the 76-m telescope. The 
results were negative, although on the basis of the signal strength at 
the last contact on 7 April, there should have been no difficulty.
Our conclusions at Jodrell Bank are therefore (i) that signals from Zond 
2 finally ceased shortly after our last contact on 7 April 1965; and 
(ii) that Zond 2 passed the vicinity of Mars on 6 August 1965. We prefer 
to accept the statement of the President of the Academy about the miss 
distance. [...] it must be emphasized that a miss distance of 1500 km 
was within the accuracy of our orbital computations."

Loss of contact with Zond 2 was confirmed on 5 May 1965 by a Soviet 
scientists delegation to a symposium in Chicago on post-Apollo space 
exploration.




LARRY KLAES wrote:
> Can it be determined once and for all and over four decades later when 
> it should
> not matter any more in terms of geopolitical prestige, if Zond 2 had a 
> lander that was
> meant to outshine Mariner 4's flyby of Mars in 1965?
>  
> Documents and photos would be nice.
>  
> Thanks,
>  
> Larry
>  
>
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