Zond 5

Computer model of a Zond circumlunar spacecraft
Names	Soyuz 7K-L1 s/n 9
Mission type	Lunar flyby Spacecraft test
Operator	OKB-1
COSPAR ID	1968-076A[1]
SATCATno.	3394[1]
Mission duration	6 days, 18 hours, 24 minutes
Spacecraft properties
Bus	Soyuz 7K-L1
Manufacturer	OKB-1
Launch mass	5,375 kilograms (11,850 lb)[2]
Start of mission
Launch date	14 September 1968, 21:42:11 (1968-09-14UTC21:42:11Z) UTC[2]
Rocket	Proton-K/D
Launch site	Baikonur81
End of mission
Recovered by	Soviet vesselsBorovichy andVasiliy Golovin
Landing date	21 September 1968 (1968-09-21) 16:08 UT[3]
Landing site	32°38′S65°33′E / 32.633°S 65.550°E /-32.633; 65.550[4] In theIndian Ocean
Orbital parameters
Reference system	Geocentric
Regime	Low Earth
Semi-major axis	6,613 kilometres (4,109 mi)
Eccentricity	0.00604
Perigee altitude	202 kilometres (126 mi)
Apogee altitude	282 kilometres (175 mi)
Inclination	51.83°
Period	89.29 minutes
Epoch	13 September 1968
Flyby ofMoon
Closest approach	18 September 1968
Distance	1,950 km (1,210 mi)
Zond ← Zond 1968B Zond 6 →

Zond 5 (Russian:Зонд 5,lit. 'Probe 5') was a spacecraft of the SovietZond program. In September 1968 it became the first spaceship to travel to and circle theMoon in acircumlunar trajectory, the first Moon mission to include animals, and the first to return safely to Earth. Zond 5 carried the first terrestrial organisms to the vicinity of the Moon, including twoRussian tortoises, fruit fly eggs, and plants.^[5] The tortoises underwent biological changes during the flight, but it was concluded that the changes were primarily due to starvation and that they were little affected by space travel.

The Zond spacecraft was a version of theSoyuz 7K-L1 crewed lunar-flyby spacecraft. It was launched by aProton-K carrier rocket with aBlock Dupper-stage to conduct scientific studies during its lunarflyby.

Out of the first fourcircumlunar missions launched by theSoviet Union there was one partial success,Zond 4, and three failures.^[6] AfterZond 4's mission in March 1968, a follow-up,Zond 1968A, was launched on 23 April. The launch failed when an erroneous abort command shut down the Proton rocket's second stage. The escape rocket fired and pulled thedescent module to safety.^[7][8] In July,Zond 1968B was being prepared for launch when theBlock D second-stage rocket exploded on the launchpad, killing three people, but leaving the Proton first-stage booster rocket and the spacecraft itself with only minor damage.^[9]

TheZond 5 mission was originally planned to flycosmonauts around the Moon, but the failures ofZond 1968A andZond 1968B led the Soviets to send an uncrewed mission instead, from fear of the negative propaganda of an unsuccessful crewed flight.^[10]

TwoRussian tortoises (Agrionemys horsfieldii) were included in the biological payload, weighing 0.34–0.4 kilograms (0.75–0.88 lb) each pre-flight.^[11] Along with the tortoises, insects and micro-organisms were part of the crew.^[12] Soviet scientists chose tortoises since they were easy to tightly secure. There were also two tortoises used as control specimens and four more in avivarium. Twelve days before launch, the two space-bound tortoises were secured in the vehicle and deprived of food and water; the control tortoises were similarly deprived.^[11] The food deprivation was a part of pathomorphological andhistochemical experiments.^[13] The biological payload also includedfruit fly eggs, cells of wheat, barley, pea, pine, carrots and tomatoes, specimens of the wildflower speciesTradescantia paludosa, three strains of the single-celledgreen algaeChlorella, and one strain oflysogenic bacteria.^[13][14] The purpose of sending a variety of terrestrial lifeforms was to test the effect ofcosmic radiation on them.^[15] However, the test subjects were not analogous to humans, because the choice of life forms were allextremophiles with a substantially higherradioresistance.^[16][17][18] TheRussian Academy of Sciences stated that a mannequin equipped with radiation sensors occupied the pilot's seat.^[1]

Kazan Optical and Mechanical Plant had developed the AFA-BA/40imager, which was installed on the spacecraft, giving it the ability toimage the Earth.^[10][19]Zond 5 also containedproton detectors.^[20]Zond 5 could transmit some of its data back to ground stations, although data stored onboard and collected after return to Earth has less noise.^[21]

Zond 5 launched on 14 September 1968 at 21:42.10 UTC, fromSite 81 at theBaikonur Cosmodrome. The thrust of the third-stage rocket was terminated at 160 kilometres (99 mi), which was the start of a 251-second coast.Block D, the upper-stage rocket, ignited and burned for 108 seconds, placing the spacecraft into a parking orbit of 191 by 219 kilometres (119 mi × 136 mi). Fifty-six minutes into the parking orbit theBlock D fired a final time for thetrans-lunar injection.^[10] After this maneuver, the launch was announced to the world.^[13] Mission Control discovered a problem withZond 5's attitude and traced the cause to a contaminated star tracker. Heat caused some of the interior coating tooutgas,^[22] which delayed an attitude correction on the way to the Moon. The maneuver was performed 325,000 kilometres (202,000 mi) from Earth using the Sun and the Earth as reference points.^[10]

On 18 September, the spacecraft flew around the Moon, although it did not orbit it.^[14] The closest distance was 1,950 kilometres (1,210 mi).^[1] On the way back from the Moon, another star tracker failed. The spacecraft also erroneously switched off the guided reentry system.^[22] Eight ships were deployed to theIndian Ocean prior to launch, as a precaution in case the spacecraft could not reach Soviet territory; only three of them had rescue helicopters on board.^[10]

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Zond 5's splashdown location

On 21 September, the reentry capsule entered the Earth's atmosphere.^[23] The primary landing zone was inKazakhstan, but insteadZond 5splashed down in the Indian Ocean and was recovered by the Soviet vesselsBorovichy (Боровичи) andVasiliy Golovnin (Василий Головнин).^[24][25] It landed at −32°38' latitude and 65°33' longitude,^[26] 105 kilometres (65 mi) from the nearest Soviet naval ship. The landing occurred at night, which impaired recovery efforts.^[27]

Zond 5 became the first spacecraft to circle the Moon and return to Earth. The entire journey took 6 days, 18 hours and 24 minutes.^[28] The biological specimens were safely recovered.^[1]USS McMorris shadowed the Soviet recovery ships, collecting intelligence,^[29] but left shortly after the spacecraft was brought on board the Soviet ship.^[27]

High-quality photographs of the Earth, the first photos of their kind,^[30] were taken at a distance of 90,000 kilometres (56,000 mi).^[1] British astronomerBernard Lovell, considered to be Britain's top space expert, said that theZond 5 mission showed that the Soviets were ahead in theSpace Race. TheBritish Interplanetary Society believed that the USSR would be able to send cosmonauts around the Moon within a matter of months.^[31]

In October 1968, sources in the U.S. claimed the mission was not as successful as the Soviets advertised. The mission had been intended to fly closer to the Moon, and its actual distance did not allow for useful lunar photography. They also said that the angle at which the spacecraft reentered the atmosphere was too steep for a cosmonaut to survive. The sources indicated that the spacecraft landed in the Indian Ocean when the planned location was in Soviet territory, which was a factor in the recovery taking ten hours.^[32]

The official Sovietnews agency,TASS, announced in November 1968 that the flight carried living animals. The tortoises weredissected on 11 October after fasting for 39 days. The flying tortoises, identified as No. 22 and No. 37, had lost 10% of their body weight during the trip, but showed no loss of appetite.^[33] The control tortoises lost 5% of their weight. Comparison of analyses of blood from the space-travelling tortoises and the control specimens revealed no differences. Another analysis showed the flying tortoises had elevated iron andglycogen levels in theirliver and that the flight also affected the internal structures of theirspleens.^[15] The authors concluded that the changes in the flight tortoises were primarily due to starvation, with the space travel having little effect.^[34] In November 1968, it was announced that the spacecraft was planned as a precursor to a crewed lunar spacecraft. The Soviets made this announcement a month before the plannedApollo 8 flight, in an attempt to show they were close to being able to carry out a crewed trip to the Moon.^[35][36]

The Zond 5 caused a scare in the United States when on 19 September 1968, the voices of cosmonautsValery Bykovsky,Vitaly Sevastyanov andPavel Popovich were transmitted from the spacecraft and intercepted byJodrell Bank Observatory and theCIA.^[37][38] The cosmonauts were apparently reading out telemetry data and computer readings, and even discussing making an attempt to land. At the height of theCold War, there was a real concern that the Soviets might actually beatNASA to the Moon.Apollo 17 astronautEugene Cernan remarked that the incident had "shocked the hell out of us."^[39]

Popovich would later recall: "When we realized we would never make it to the moon, we decided to engage in a little bit of hooliganism. We asked our engineers to link the on-the-probe receiver to the transmitter with a jumper wire. Moon flight missions were then controlled from a command centre inYevpatoria, in theCrimea. When the probe was on its path round the Moon, I was at the center. So I took the mic and said: "The flight is proceeding according to normal; we’re approaching the surface..." Seconds later my report – as if from outer space – was received on Earth, including [by] the Americans. The U.S. space advisorFrank Borman got a phone call from PresidentNixon [actuallyJohnson], who asked: 'Why is Popovich reporting from the moon?' My joke caused real turmoil. In about a month's time. Frank came to theUSSR, and I was instructed to meet him at the airport. Hardly had he walked out of his plane when he shook his fist at me and said: 'Hey, you, space hooligan!'"^[40]

TheZond 5 capsule is on display at theRKK Energiya museum, located inMoscow Oblast, Russia.^[41]

• Animals in space
• Zond 6, turtles on a circumlunar mission in November 1968
• Zond 7, four turtles flew the August 1969 circumlunar flight
• Fe, Fi, Fo, Fum, and Phooey, five mice who orbited the Moon a record 75 times in December 1972, while traveling on NASA'sApollo 17 mission
• List of missions to the Moon
• Korabl-Sputnik 5, another Soviet mission some mistakenly thought was crewed.

• Cassutt, Michael (2007).Red Moon. Tom Doherty Associates.ISBN 978-1-4299-7172-0.
• Gaidamakin, N. A.; Parfenov, G. P.; Petrukhin, V. G.; Antipov, V. V.; Saksonov, P. P.; Smirvona, A. V. (1969). Zug, George R.; Peters, James A. (eds.).Патоморфологические и гистохимические изменения в органах черепах на борту космического корабля «Зонд-5» [Patho-Morphological and Histochemical Changes in the Organs of Turtles on Board the "Zond-5" Probe](PDF). 18th IAF Conference (in Russian). Translated by Friedman, Morris D. La Plata, Argentina.
• Siddiqi, Asif A. (2018).Beyond Earth: A Chronicle of Deep Space Exploration, 1958–2016(PDF). Washington, D.C.: NASA History Program Office. p. 80.ISBN 9781626830424.LCCN 2017059404. SP-2018-4041.
• Siddiqi, Asif A. (2003) [2000].The Soviet Space Race with Apollo. Gainesville, Florida: University Press of Florida.ISBN 978-0-8130-2628-2.

• Zond 5 image of Earth

• Missions to the Moon
• Zond program
• Spacecraft launched in 1968
• 1968 in the Soviet Union
• Lunar flybys
• Animals in space
• Animal testing in the Soviet Union
• Individual tortoises
• Animal deaths by euthanasia

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