Zond-7: After the race
On Aug. 8, 1969, just two weeks after the Apollo-11 astronauts had returned to Earth, the USSR launched its 11th prototype of the L1 vehicle originally intended to carry crew around the Moon. Despite Zond-7's good performance in flight, it was too little, too late for the politicians in Moscow.
Photos of the Earth and the Moon attributed to the Zond-7 mission. Credit: RKK Energia.
The Zond-7 mission at a glance:
Preparations for flight
The active assembly of Vehicle No. 11L within the L1 series was conducted at the TsKBEM design bureau in Podlipki during much of 1968, in parallel with the work on hardware for the 7K-OK Soyuz project. Initially, the 11th mission of the L1 spacecraft was expected to take place in the second half of 1968, well within the piloted phase of the circumlunar flight program, but, as technical problems with the spacecraft and its rocket persisted, robotic test launches consumed more and more vehicles.
From the notes by the TsKBEM chief Vasily Mishin made in February 1968, it appears that the launch of the 11th L1 ship was planned as early as September. However, on August 13, 1968, Mishin mentioned delays with the assembly of Vehicle No. 11P (where "P" likely stood for "piloted"). In particular, Mishin referred to some issues with the internal arrangement inside the Descent Module of the spacecraft.
Still, there was hope at the time, that a crew would still be onboard the ship during the mission around the Moon. For example, during a meeting on September 25, 1968, Mishin wanted to make sure that crews would participate in the testing of the fresh vehicles. (774)
After all the delays, Vehicle No. 11 was finally ready for testing by the end of January 1969, however, on February 1, head of cosmonaut training Nikolai Kamanin already cited cosmonauts as being concerned about Mishin's talk to terminate the L1 project, clearly in the wake of the Apollo-8 mission, which put the American crew in orbit around the Moon in December 1968. (820)
Then, during a major strategy meeting chaired by the Minister of General Machine-building Sergei Afanasiev, who oversaw the rocket industry, on Jan. 10, 1969, Mishin's deputy Sergei Okhapkin reported about plans to prepare vehicles No. 11, 13, 14. By that time, there was no longer talk of flying a crew aboard Vehicle No. 11. (774)
Moreover, after the failed launch of the L1 No. 13L spacecraft in January 1969, the priorities clearly shifted away from the L1 project and the next ship would not make it to the launch pad until the following August. Even more so than its ill-fated predecessor, the 11L mission became an experience-gaining exercise driven by the inertia of a defunct political goal.
Still, during the processing of Vehicle No. 11L at the launch site in Tyuratam, Soviet cosmonauts Aleksei Leonov and Oleg Makarov, who trained to fly the L1 ships, worked as test operators of its Descent Module. The capsule was also staffed with the two mannequins, apparently, to precisely position the center of gravity of the spacecraft with a crew onboard. According to the Moscow Polytech Museum, the mannequin also represented a tissue equivalent of a human body with embedded sensors designed to measure the effects of space radiation. The face of at least one of the mannequins apparently was made as a likeness of Yuri Gagarin.
Also, upon arrival at the launch pad, the mission's flight assignment was uploaded into the ship's newly installed flight control computer, the pilot's flight control console in the Descent Module was powered up and all the circuit breakers were removed from the cabin's equipment, as it would be done if a crew was onboard. (52)
Vehicle No. 11L flight
The UR-500K rocket with L1 No. 11L spacecraft lifted off from the "Left" pad at Site 81 in Tyuratam on August 8, 1969, at 02:48 Moscow Time. (400) The Block D upper stage then successfully boosted the spacecraft from its initial parking orbit on a trans-lunar trajectory and the spacecraft then performed a first orbit correction, at a distance of 250,000 kilometers from Earth. (2) The mission was publicly announced as Zond-7.
The flight profile was largely identical to previous launch attempts in the L1 project targeting a single loop behind the Moon. Once again, the ONA high-gain antenna failed to deploy early in flight, apparently due to a tangled folding line. (202) Fortunately, the issue did not prevent basic flight control operations. (231)
One major new instrument aboard Zond-7 was the Kiev-S medium-format camera, also known as SKD, SKM or S-80. It was developed by the Arsenal factory in Kiev, in the Ukrainian Republic. The camera was controlled with a command instrument developed at the MIIGAiK geodesy and cartography institute in Moscow. (874)
During the flight, the Kiev-S was used to take several color photos of the Earth and the Moon, including a classic scene of the earthrise over the lunar horizon. The two photo sessions were conducted at distances of 10,000 and 2,000 kilometers from the Moon. (2) Mission control also tested navigating the spacecraft with the help of the Argon-11s onboard computer. (874)
On August 11, Zond-7 flew at a minimum distance of 1,230 kilometers from the Moon. After the flyby, the spacecraft headed back to Earth and made a successful landing on August 14, 1969. Like in the previous Zond-6 mission, the Descent Module returned along the so-called skip reentry trajectory, when the Descent Module approaching the Earth from the Southern Hemisphere used its aerodynamic lift capability to exit the atmosphere after the initial entry and then re-enter again, thus extending its descent trajectory to reach the Soviet territory in the Northern Hemisphere.
On August 22, the Pravda newspaper, the official mouthpiece of the Communist Party, published the first black and white images produced during the Zond-7 mission. Color versions of the photos later appeared in magazines. (874)
Still, Western observers noticed that the coverage of the Zond-7 mission in the official Soviet press had been more scarce, compared to the fanfares during the flights of Zond-5 and Zond-6. (50) It was a clear hint that after the success of the Apollo-11, the Zond program had lost its political significance.
Ironically, the Zond-7 spacecraft was the first in the L1 series which would have safely returned its crew back to Earth had cosmonauts been onboard. According to Kamanin, that fact gave enough confidence to Afanasiev and Mishin to resume the conversation around August or September 1969 about flying a crew around the Moon.
On September 19, 1969, the State Commission met to discuss the results of the Zond-7 mission and scheduled another launch of a pilotless L1 spacecraft in December 1969, which, in case of a complete success, would clear the way to a mission with a crew onboard in April 1970, just in time for the 100th anniversary of Vladimir Lenin, the founder of the Soviet Union.
Unfortunately, the political leadership in Moscow remained unimpressed and by the end of 1969, the L1 program was de facto cancelled. (231)
The UR-500K-L1 complex is being loaded on the transporter/erector system in preparation for rollout from the vehicle assembly building to the launch pad. Credit: Novosti Kosmonavtiki
Kiev camera that was installed aboard Zond-7. Credit: (874)
Photos of the Earth and the Moon attributed to the Zond-7 mission. Credit: RKK Energia
A Soviet post stamp dedicated to the Zond-7 mission. Anatoly Zak's collection