According to a message to Jodrell Bank from Dr Alla Massevitch the last contact with Venera 1 occurred on 17 February 1961 at 1404-1535 MT. Dr Massevitch explained in another report (53) that the probe "was designed to transmit signals every five days. For about 17 minutes it should have sent out an unmodulated sound, and then transmitted coded messages giving scientific information such as temperature, pressures, and the presence of meteorites." So, presumably, the probe malfunctioned some time between 17 and 22 February 1961. However, Soviet tracking stations had computed that the probe would indeed pass near Venus and asked Jodrell Bank to try to pick up telemetry from the probe when it passed closest to Venus on 17 May 1961. Presumably a command to switch on the probe's transmitter was sent from the main Soviet ground station in the Crimea. Jodrell Bank did pick up unidentified signals on 922.8 MHz on 17 May 1961 and sent them to Moscow for analysis. Obviously nothing relating to Venera 1 had been heard since Soviet authorities never claimed to have regained contact with the probe.
However, Soviet authorities did not lose all hope of contacting the probe. Soviet scientists Drs Massevitch and Khodarev were invited to Jodrell Bank by Prof. Lovell in a telegram dated 30 May 1961 and certainly visited the observatory from 9-16 June 1961 and tried to pick up more signals from Venera, but to no avail (53). Telegrams from Moscow with pointing data for Venera 1 continued to be sent to Jodrell Bank in support of this last-ditch reception attempt. The last telegram from Moscow with pointing data for the Venera 1 probe that I could find in the Venus probe file in the Jodrell Bank Archives is dated 20 June 1961.
Soviet
media published an extensive description of the probe's mission and its
subsystems. The radio systems were described as follows: "The craft
carries three radio systems, working on wavelengths in the metre (1.6m),
decimetre (32cm) and centimetre (5 and 8 cm) ranges....The radio complex
working in the metre range serves both for transmission of telemetric information
about condition of the station and for maintaining communication with the
earth in the event of abnormal functioning of the orientation system."
(52)An
interpretation of this description can be found in Radio
Systems of Soviet Mars and Venus Probes.
Obviously Jodrell Bank tracked the Mars 1 probe and telegrams
giving transmitter ON times for Mars-1 and pointing data were regularly
sent to Jodrell Bank from Moscow. It was necessary for Jodrell Bank to
know when the probe's transmitters would be on because they operated for
only an hour or so a day. For example, Mars 1 transmitters would be operating
at 0850-1040 Moscow Time on 27 November 1962, at 0825-0955 Moscow Time
on 7 December 1962, and at 1700-1830 Moscow Time on 15 January 1963. Until
13 December 1962 the probe operated at regular two-day intervals between
communications session and then changed to five-day intervals (52).
Moscow even gave (44) details about the radio
systems of Mars 1: "The telemetry transmitter operates on 922.8 MHz
with +/- 120 deg phase modulation with the subcarrier frequency in the
range 1100-1700 Hz, during telemetry transmission the subcarrier frequency
is modulated in frequency by a code signal." All went well for Mars-1
for the first five months, but on 21 March 1963 all contact with the probe
was lost due to an orientation system problem. Mars-1 is estimated to have
passed Mars at a distance of 193000 km on 19 June 1863.
Jodrell Bank was also successful in picking up the Zond
2 probe launched to Mars on 30 November 1964. Contact with the probe was
irregular and uncertain according to (47).
This
seems to contradict a magazine report (48)
which stated that Zond 2 was received regularly by Jodrell Bank. In January
1965 and at around 2100 UT on 3,10 and 17 February 1965 signals were picked
up using the 15 meter dish at Jodrell Bank. In the same report a
visit by Soviet scientists to Jodrell Bank on 17 February 1965 is described.
Academician Keldysh was asked whether Jodrell Bank would be requested to
track any Soviet space probe in the future and replied "We shall whenever
it is necessary". On May 5, Gennadi Skuridin, on a visit to the
U.S., reported that "Transmissions from Zond 2 have stopped. We have
been unable to raise it again". (49)It
flew past Mars silently on 6 August, 1965.
|
The first space probe that reached the surface of Venus in working condition was Venera 4. It was launched on 12 June 1967 and entered the atmosphere of Venus on 18 October 1967. The 384 kg capsule transmitted data for 94 minutes. The capsule was crushed by atmospheric pressure at 18 bar when it was at an altitude of 22 km experiencing an outside temperature of 274oC. It dropped to the surface of Venus at a point near 19N 38E longitude.
Jodrell Bank tracked the
flight's approach to the surface. The observatory picked up signals from Venera
4 at 0317 UT on 18 October 1967, some
forty minutes after Venus rose above the horizon. The signals were similar
to those that Jodrell Bank had picked up in July 1967. The signal was described
(56)
as "two tone telemetry similar to the Lunik's transmissions but speeded
up four times." Doppler shift measurements were made and they showed
that the distance to venus was 30000 km at 0440 BST and the probe accelerated
along the line-of-sight with 0.3 m/s2.
The received signal strength was -140 dBm. Jodrell Bank expected, that
if the probe would orbit Venus, it would slow down and the Doppler shift
would reveal that between 0403 and 0450 UT. But, no such slowing down was
noticed, rather the opposite. the probe continued to accelerate towards
the surface and at 0415 UT the probe was estimated to have been 10000 km
form the surface. At 0438:05 UT the signals ceased, at an estimated altitude
of 100 km. Fifteen seconds later the signal re-appeared on the same frequency,
at 20 dB down and with a much reduced data rate. The Doppler shift in this
signal was very small and initially, the Jodrell Bank team thought the
capsule rested on the surface. The signals ceased finally at 0614 UT.
There was not enough time to redesign the next batch of
Venus probe, so Venera 5 and 6 met the same fate as Venera 4. Venera 5
survived for 53 minutes in the atmosphere and reached 26 km from
the surface. Venera 6 said to have survived to 10-12 km altitude 51 minutes
after atmospheric entry. (54) The
landing capsules of the next batch of two Venus probes launched in August
1970 were modified to survive to the surface. One probe failed to leave
Earth orbit and was given the cover name Kosmos 359. Venera 7, launched
on 17 August 1970, was equipped with a redesigned landing capsule that
could stand 180 atm and 540oC.
Radio signals appeared to stop after 35 minutes, but weak signals, 20 dB
down, were found (by post-flight signal processing) to have continued
for 23 minutes. The capsule landed at 5oS,
351o longitude. The
environment on the surface measured to be 90 +/- 15 atm, 475 +/- 20oC.
The following probe, Venera 8, launched on 27 March 1972, had a detachable
antenna to solve the previous probe's problem and worked very well. The
environment on the surface was 470 +/- 8oC,
93 atm.
Luna 4,5,6,7,8 - trying again and again to land on the moon
The first of these new Luna probes that was announced
as such was Luna 4, launched on 2 April 1963. The Soviet Union did
not ask Jodrell Bank to track the flight, but Jodrell Bank finally acquired
Luna 4 during 6 hours on 4 April after searching for it since 2 April (31).
Signals were far more complicated than those from Luna 3. On the day it
flew past the Moon (at 0124 UT at a distance of 8500 km), 6 April, signals
were recorded for 44 minutes, but there were no signs of firing of retro-rockets
at the Moon (19). Despite
the lack of a direct request for support from the USSR, Soviet media gave
the transmission frequency - 183.6 MHz (32),
and also the traditional position fix giving a distance from the earth
at certain geocentric co-ordinates at a defined instant. This was clearly
an invitation to monitor signals in order to obtain independent confirmation
of Soviet claims. The table on the left shows the navigation fixes for
Luna 4-14 published in the official launch communiqués from TASS
(33).In
addition to the tracking reports from Jodrell Bank, the US National Security
Agency had arranged with the Naval Research Labs in Maryland to use its
45 m dish to track Luna 4. Because the flight to the moon took 88 hours
instead of 80 hours even a station as far west as on the US east coast
could pick up the signals on 183.6 MHz, which were "complicated and full
of variety"
(2). (see Luna 4-14
radio systems
for a detailed
description).
Two more launch attempts were made in 1964. The first launch took place on 21 March and failed when he thirs stage did not reach full thrust. The second attempt took plcae less than a month later, on 20 April 1964, when the third stage again cut off prematurely.
A year later, in the spring of 1965, this spacecraft series resumed with attempts to land on the Moon - the so-called E6 probe. The first two attempts failed. The probe launched on 12 March 1965 was left stranded in Earth orbit as Kosmos 60, while probe launched on 10 April never reached orbit due to a third stage failure. On 9 May Luna 5 finally was injected into a trans-lunar trajectory. Both the new NSA station at Asmara, Ethiopia (See article on the US "Deep-Space Collection" programme), and Jodrell Bank tracked Luna 5 which transmitted similar telemetry to that from Luna 4. The Asmara station intercepted "both of the two spacecraft signals several times during the mission, and both Asmara and Jodrell Bank were listening during the final approach to the moon" (2). Two signals - indeed! 183.6 MHz and what other frequency? 922.7 MHz? However, the Doppler measurements made at Jodrell Bank revealed no signs of retro-rocket firing from Luna 5 (20). Luna 6 was launched on 8 June 1965, but the course-correction was not turned off correctly on 9 June causing the probe to miss the Moon by 161000 km and enter heliocentric orbit. Luna 7 was launched on 4 October 1965. From observations made at Jodrell Bank (20) it was conclude that the retrorockets of Luna 7 were in operation during the period 2058-2104 UT on 7 October 1965. However, this turned out to be wrong. According to what we know now (61) the retro-rocket never fired because the earth sensor lost lock just before ignition. The probe crashed into the Moon at 2208.24 UT. Luna 8 was launched on 3 December 1965, but thus time the retrorockets fired too late. Signals received at Jodrell Bank from Luna 8 ceased at 2151.32 UT on 6 December 1965 (21), which we now know was the moment of impact. The retro-rocket did not ignite.
Luna
9 - the first landing on the moon
The tracking of Luna 9 was to become Jodrell Bank's most spectacular, dramatic, and controversial appearance in the media. Luna 9 was launched from Baikonur on 31 January 1966 and was immediately recognized by all observers as another Soviet attempt to land an instrument package on the moon. The moon rose at Jodrell Bank on 3 February 1966 at 1333 UT. Signals from Luna 9 were received starting at 1629 UT until landing at 1845 UT. After a few minutes of silence the signal reappeared. Ten minutes later it changed character and the signal was recognized as facsimile because it was similar to signals used in transatlantic transmissions experiments using the Echo II balloon satellite (27).When I visited Jodrell Bank in September 1967 the public affairs officer, Reginald Lascelles, explained that he had been the person identifying the signal as being facsimile, because of this previous employment in newspapers where he had heard the characteristic sound of facsimile signals! Be that as it may - someone recognized the signal as facsimile!
The pictures from Luna 9 were received on 4 February 1966 at 1530-1655 UT and again on 5 February at 1640-1740 UT. Other facsimile transmissions were received on 3,4 and 6 February "which we have not seen as photos" (22) . Jodrell Bank recorded long series of telemetry bursts, each lasting six minutes and corresponding to one picture (23). The international facsimile standard is that the White/black transition corresponds to a a change in audio frequency between 1.5 to 2.3 kHz, while the Luna 9 transmissions used a change from 1.2 to 2.0 kHz. The difference in horizontal/vertical ratio was sometimes given as a factor 2 and sometimes as a factor 2.5 . The picture signals were transmitted on a subcarrier with maximum deviation of 2 kHz. The synchronization signal for the pictures (start of each line?) was a tone with the frequency 1.1 kHz (24). The lunar panoramas consisted of vertical lines with 500 elements (each 3.6 minutes of arc wide) and the 360 degree view around the horizon consisted of 6000 such lines (25). Jodrell Bank recorded the Luna 9 pictures on a Mincom CM-110 tape recorder (62) .
The fact that Jodrell Bank used a standard facsimile receiver (borrowed from the Daily Express in Manchester) to print the pictures coming in from the moon and did not recognize that the horizontal/vertical ratio did not conform to the international standard led to an exchange of harsh words with Soviet Academy of Sciences. Naturally, the Soviet authorities would have liked to publish the pictures at their own initiative and used the fact that the pictures published by Jodrell Bank were not quite correct as a pretext for complaining about about the premature release of the pictures. Prof. Lovell defended himself by pointing out the great general interest of the pictures from moon and that the pictures still showed the correct qualitative characters of the lunar surface. This conflict with Soviet authorities is not only evident from public exchanges, but also from correspondence in the Jodrell Bank Archives where I found a letter (43) from the Academy of Sciences of the USSR complaining about the "hurried publication of the Luna 9 pictures" by Jodrell Bank.
Incredibly,
just as in the case of Luna 2 there were disbelievers that asked Jodrell
Bank for proof of this latest Soviet feat. Thus, The "Anti-Communist League
of America, Inc." (Carrying the text: "Communism must be destroyed" in
its letterhead) wrote (26) to request
information about the descent phase of Luna 9. In reply, they received
a reprint of the article in Nature about Jodrell Bank's reception of signals
from Luna 9 (28).
Luna 10, 11, and 12 - shifting the focus to lunar orbit
When Luna 9 had succeeded in landing on the moon, the Soviet focus immediately shifted to putting a probe into orbit around the moon. In February 1966, Kosmos 111,a failed lunar probe was launched [give details about reason for failure and details such as HF frequency]. Another attempt, this time successful, was made on 31 March 1966, when Luna 10 was launched. Jodrell Bank successfully tracked the probe, detected its insertion into lunar orbit and measured its period (35). Other tracking stations, such as the Bochum Space Observatory in Germany, also picked up the probe, including the transmission of the tune "The International" (38 kB mp3) at 1944-1950 UT on 3 April 1966 (34) . This transmission was made to celebrate the 23 rd Congress of the CPSU. The two following probes in the E6 Luna series were also orbiters. The character of Luna 11 has been hotly debated and some authors think that Luna 11 was similar to Luna 10, i.e. it had a non-stabilized orbiter, while other space historians think it was similar to Luna 12, which did not separate a payload in lunar orbit and actually produced pictures of the moon. The only evidence, although inconclusive, as to the character of Luna 11 found in the Luna 11 archives is a statement (36) by Prof. Lovell explaining that "we received facsimile signals for a short time from Luna 11 which appeared to be of identical form to those transmitted by Luna 9. However, it proved impossible to make anything of the information."
I found nothing about Luna 12 in the Jodrell Bank Archives.
Perhaps this was due to the fact that special measures were taken to ensure
that Jodrell Bank would not be able to repeat its Luna-9 scoop during the
Luna-12 mission (59 p. 46). One option considered
was to gradually send back the pictures during the brief windows that Luna-12
was only within range of the Crimea, which could pick up the spacecraft
three hours before it entered Jodrell Bank’s radio visibility zone. However,
in that mode "it would have taken months" for the pictures to trickle
down to Earth. Another solution was found, enabling the Russians to send
back the pictures in 24 hours, while still leaving Jodrell Bank empty-handed.
As one of the Lavochkin bureau veterans explained : “We were able to
send back information in two bands, the metre and decimetre bands, and
to quickly switch from one band to the other, while Jodrell Bank needed
about a day to reconfigure its equipment [for this] ... That is the way
we worked : we made full use of the [three hour Soviet window] and then,
as the probe came within range of Jodrell Bank, began alternating between
the two modes in varying sequences, playing cat and mouse with Jodrell
Bank. We successfully completed our nearly round-the-clock work to send
back the images and breathed a sigh of relief. It was as if a great weight
had been lifted from our shoulders." (59)
Luna 13 and 14
After
Luna 12 The Soviet union launched a second lunar lander, Luna 13,
equipped with several new devices, including a device to measure the hardness
of the lunar surface. Jodrell Bank tracked Luna 13 and received images
in the same fashion as from Luna 9. The final launch
in this series occurred almost 18 months later, on 7 April 1968. It was
Luna
14 and pictures of the Luna 12 probe (which it probably resembled)
show a conical antenna obviously intended for the standard 768/922 MHz
TT&C system. It has been reported that Luna 14 was a test of various
subsystems for the next generation of Luna probes, including the drive
system for the Lunokhod lunar rovers. There is a message (45)
in the Jodrell Bank Archives to professor Lovell while he was in the U.S.
that the observatory had picked up Luna 14: "PLEASED TO INFORM YOU SIGNALS
FROM LUNAR ORBITER 14 RECEIVED.". Of course the telegramme refers to
Luna 14.
The Zond designation was confusingly used also for the series of Soviet space vehicles that tested a manned circumlunar spacecraft. Perhaps the intention was to be able to hide the true nature of these craft in the case the program failed. The first two test launches of these Zond craft (see "The continuing enigma of Kosmos 146 and Kosmos 154") were mainly tests of the propulsion system needed to leave earth orbit. Kosmos 146 seems to have been partially successful, while Kosmos 154 was a failure because the ullage rockets needed to restart the last stage of the Proton launch vehicle were discarded prematurely. During the second half of 1967 the Soviet Union made extensive efforts to launch the first "full-up" unpiloted test of the Zond circumlunar mission. After several attempts in August and September the launch finally occurred at 1907:59 UT on 22 November 1967 (42). Analysis (see "Mission profiles of 7K-L1 flights") shows that this launch was aimed at the moon, but the launch failed due to a second stage engine failure.
Zond 4 and the launch attempt in April 1968
The next launch, of Zond 4, took place at 1828 UT on 2 March 1968 and, strangely, it was launched on an elliptical orbit away from the moon. [Explain fate]. It is unclear if Jodrell Bank tracked this flight. Russian media were very reticent concerning this flight. The next launch attempt in the Zond program occurred very soon after Zond 4. A Zond was launched in the direction of the moon at 2301:57 UT on 22 April 1968 (42). This flight also failed because premature cutoff of the second stage due to a short circuit.
Zond 5 - a strange Soviet game of hide-and-seek and voices from the sky
The next launch took place after the summer of 1968 when
Zond 5 was sent on a circumlunar trajectory in September. Jodrell Bank
certainly tracked
this flight, but antenna pointing angles in all probability did not come from
the Russians, but rather from the
U.S. Deep-Space Collection Programme
. From press reports we know that Jodrell
Bank intercepted signals, including voice signals uplinked to the spacecraft
from Yevpatoria and returned by the spacecraft to simulate the presence
of a cosmonaut. These Zond spacecraft did not transmit in intermittent
communications sessions as the Luna probes, but instead their transmitters
were operating continuously on 922.76 MHz. (See
Zond 4-8 radio systems) In the case of Zond 5, Soviet authorities
played a bizarre game of cat-and-mouse with the media, initially denying that
the spacecraft was going to the moon:
"What happened at the moon at 0455 UT this morning[18 Sept 1969]? The head of the Jodrell Bank observatory in England, professor Bernard Lovell, says that a Soviet spacecraft rounded the moon and started on its way back to earth at that time. A few hours later this report was denied by a spokesman of the foreign office in Moscow. The report does not agree with facts, he said. At Jodrell bank, engineers monitored signals all night from a spacecraft near the moon. They heard signals regularly at 40 minute intervals. At 0455 UT this morning they found that the spacecraft had circumnavigated the moon at a minimum distance of 1500 km. The craft then headed back to earth along an elliptical trajectory. No retrorockets were fired...." (40)
After
Zond 5 had passed the moon there were more surprises in store for those
monitoring the flight at Jodrell Bank: "On the night of 19-20 September,
the craft was clearly observed by Jodrell Bank to be on the return swing
and a Russian voice, presumably tape-recorded, was heard calling out instrument
values, as though communications were being tested for a subsequent manned
mission." (39). It turned out that
such voice signals were also picked up by the Bochum space observatory
(41).
According to the observatory's director, Heinz Kaminski, the voice had
been either sent from Earth to the spacecraft or the other way by means
of a tape recorder.
On Friday 20 September, TASS finally ended the bizarre hide-and-seek and announced that Zond 5 had passed within 1950 km of the moon's surface at 0440 UT on 18 September and was heading back to earth. (See table below for a complete timeline of the Zond 5 flight). The flight ended on 21 September 1968. Jodrell Bank lost contact at 1500 UT on 21 September 1968 when the spacecraft was 80000 km from earth. The descent vehicle separated at 1530 UT and re-entry started at 1554 UT. The radio black-out period ended at 1558 UT and splashdown occurred at 1608 UT in the Indian Ocean off Madagascar.
Zond 6 - a dress rehearsal that went wrong?
Zond 6 was launched at 1911:31 UT on 10 November 1968, rounded the Moon at a distance of 2420 km on 14 November and on 17 November it made a skip-lob re-entry into Soviet airspace. Howeveer, the re-entry capsule crashed to the ground because of a faulty parachute, but the pictures take at the Moon could be rescued and published. In this way the flight was erroneously regarded by many Western observers as a complete success leading up to a piloted circumlunar flight within short. Very little information about Jodrell Banks' tracking of Zond 6 can be found in the Jodrell Bank Archives, but they do contain the typed text of a statement to the press dated 14 November 1968: Zond 6 passed behind the Moon from 0350 to 0420 a.m. (given as 0250-0320 UT in (37). ) at a distance similar to that of Zond 5, that is between 1000 and 2000 miles. There was no guidance or firing of retrorockets and the Zond now appears to be on its return journey to earth. Tracking is continuing until the probe sets early this afternoon and will be resumed tonight. The only other document about the Zond flights found in the "lunar probes" file of the Jodrell Bank Archives is a letter from Prof. Lovell to Prof. DWR Wilson, University of Alberta, dated 27 November 1968 in which he explained that "...Zond 5 and 6 set below our horizon several hours before re-entry.."
In August 1969, a few weeks after the flight of Luna 15
and Apollo 11, the Soviet Union launched the next Zond flight, but it was
still unmanned. It was the first, and as it turned out, only really successful
flight in the Zond series. Jodrell Bank tracked the flight and informed
the media that Zond 7 also transmitted voice communications, and that signals
were much stronger than those from Zond 6 (38).
We now know that yhis observation is explained by the fact that the high-gain
antenna on Zond-6 did not deploy, while it apparently did on Zond-7. (60).
Jodrell Bank again came to play a major role in monitoring the flight and in interpreting the flight events to the general public. Professor Lovell noted that the probe was on a "slow" trajectory to the Moon, taking a day longer to reach the Moon that previous Luna flights.
On July 17, as Luna 15 entered lunar orbit, Jodrell
Bank reported that the signals from Luna 15 "are of an entirely new
type never heard before." (46)
It is hard to know if this means that Jodrell Bank had never before tracked
a Luna probe on 922.8 MHz (which we know was used by Luna 15) or that the
telemetry format was much different (See Radio
Systems used by the Luna 15-24 series of spacecraft). At this time
Jodrell bank was co-operating closely with the US Deep Space Collection
effort and this organization may have helped Jodrell Bank find the correct
frequency and location the spacecraft in the sky.However,
Jodrell Bank provided the news about the final phase of the Luna 15 drama
in a news release:
"Signals ceased at 4.50 p.m. this evening [1550 UT on 21 July 1969; Soviet news releases gave the time as 1551 UT]. They have not yet returned. The retrorockets were fired at 4.46 p.m. [1546 UT; Soviet news releases gave the time as 1547 UT] on the 52nd orbit and after burning for 4 minutes the craft was on or near the lunar surface, The approach velocity was 480 km/h [presumably determined by measuring the Doppler shift] and it is unlikely of anything could have survived."There was a bizarre incident during the flight. In the U.S. the notion was raised that Luna 15 could possibly interfere with Apollo 11 in some way. NASA let Frank Borman, commander of Apollo 8, approach the Soviet Academy of Sciences to find out if there was any risk of radio interference to Apollo 11 from Luna 15 operations near the Moon. The Soviets replied and it seems that the frequency 115 MHz was raised in this exchange.
Suppose Luna 15 had worked perfectly, would it have beaten
Apollo to returning the first lunar samples to earth? By using the flight
profiles of Luna 16,20 and 24 one can deduce that Luna 15 could have returned
to earth 12.44 days after launch. This would be July 25.565 (i.e. at 1334
UT on July 25, almost a day after the splashdown of Apollo 11, which took
pace at 1635 UT on 24 July! So, Apollo 11 would not have been beaten anyway!
Even if Luna 15 had been able to stick to the quickest return flight schedule
(that of Luna 16) it would have been back after 11.65 days, i.e. at 0100
UT on 25 July - even this after the return of Apollo 11!