Ye-8 lunar probe
Ye-8 lunar sample return spacecraft - detail of drill and re-entry vehicle
Credit: © Mark Wade
Korolev / Lavochkin E-6M spacecraft as flown on Luna 9 first soft landing on the moon.
Credit: Andy Salmon
Korolev / Lavochkin E-6M spacecraft as flown on Luna 13 with soil probe.
Credit: Andy Salmon
The Lunokhod unmanned lunar surface rover.
Lunar probe; passed within 5,995 km of moon but did not hit it as planned due to a failure of the launch vehicle control system. Went into solar orbit. First manmade object to attain of escape velocity. Also known as Mechta ("Dream"), popularly called Lunik I. Because of its high velocity and its announced package of various metallic emblems with the Soviet coat of arms, it was concluded that Luna 1 was intended to impact the Moon. After reaching escape velocity, Luna 1 separated from its 1472 kg third stage. The third stage, 5.2 m long and 2.4 m in diameter, travelled along with Luna 1. On 3 January, at a distance of 113,000 km from Earth, a large (1 kg) cloud of sodium gas was released by the spacecraft. This glowing orange trail of gas, visible over the Indian Ocean with the brightness of a sixth-magnitude star, allowed astronomers to track the spacecraft. It also served as an experiment on the behavior of gas in outer space. Luna 1 passed within 5,995 km of the Moon's surface on 4 January after 34 hours of flight. It went into orbit around the Sun, between the orbits of Earth and Mars. The measurements obtained during this mission provided new data on the Earth's radiation belt and outer space, including the discovery that the Moon had no magnetic field and that a solar wind, a strong flow of ionized plasma emmanating from the Sun, streamed through interplanetary space.
First probe to impact lunar surface. Delivered a pennant to the surface of the Moon and conducted research during flight to the Moon. Impacted Moon 13 Sep 1959 at 22:02:04 UT, Latitude 29.10 N, Longitude 0.00 - Palus Putredinis, east of Mare Serenitatis near the Aristides, Archimedes, and Autolycus craters. After launch and attainment of escape velocity, Luna 2 separated from its third stage, which travelled along with it towards the Moon. On 13 September the spacecraft released a bright orange cloud of sodium gas which aided in spacecraft tracking and acted as an experiment on the behavior of gas in space. On 14 September, after 33.5 hours of flight, radio signals from Luna 2 abruptly ceased, indicating it had impacted on the Moon. Some 30 minutes after Luna 2, the third stage of its rocket also impacted the Moon. The mission confirmed that the Moon had no appreciable magnetic field, and found no evidence of radiation belts at the Moon.
Luna 3 was the third spacecraft successfully launched to the Moon and the first to return images of the lunar far side. It was launched on a figure-eight trajectory which brought it over the Moon (closest approach to the Moon was 6200 km) and around the far side, which was sunlit at the time. It was stabilized while in optical view of the far side of the Moon. On October 7, 1959, the television system obtained a series of 29 photographs over 40 minutes, covering 70% of the surface, that were developed on-board the spacecraft. The photographs were scanned and 17 were radio transmitted to ground stations in facsimile form on October 18, 1959, as the spacecraft, in a barycentric orbit, returned near the Earth. The photographs were to be retransmitted at another point close to Earth but were not received. The spacecraft returned very indistinct pictures, but, through computer enhancement, a tentative atlas of the lunar farside was produced. These first views of the lunar far side showed mountainous terrain, very different from the near side, and two dark regions which were named Mare Moscovrae (Sea of Moscow) and Mare Desiderii (Sea of Dreams).
Luna 4 was the second attempted Soviet unmanned lunar soft lander probe. The spacecraft, rather than being sent on a straight trajectory toward the Moon, was placed first in an earth parking orbit. The rocket stage then reignited and put the spaccecraft on a translunar trajectory. Failure of Luna 4 to make a required midcourse correction resulted in it missing the Moon by 8336.2 km on April 6, at 4:26 a.m. Moscow time. It thereafter entered a barycentric Earth orbit. The Soviet news agency, Tass, reported that data had been received from the spacecraft throughout its flight and that radio communication would continue for a few more days.
Soft lunar landing attempt. Western observers, among them England's Sir Bernard Lovell, correctly speculated that the craft's mission was a soft landing. After launch fom Baikonur and five successful communications sessions the spacecraft performed a midcourse correction maneuver on 10 May. Unfortunately a problem developed in a flotation gyroscope (it did not have enough time to warm up properly) in the I-100 guidance control unit and control was lost so the spacecraft began spinning around its main axis. It was brought back under control, but at the time of the next maneuver, the main retrorocket system failed due to a ground control error in calculating the setpoints, and the spacecraft, though still headed for the Moon, was far off its intended landing site. Problems again cropped up with the I-100 unit so a retrorocket burn could not take place and Luna 5 impacted the lunar surface some 700 km from the target point at about 19:10 UT on 12 May 1965, becoming the second Soviet probe to hit the Moon. A Soviet announcement gave the impact point as the Sea of Clouds at roughly 31 degrees S, 8 degrees W. (Although a later analysis gave a very different estimate of 8 degrees N, 23 degrees W.)
Attempted unmanned lunar soft lander. Tass reported that all onboard equipment was functioning normally. During the mid-course correction on 9 June the main retro-rocket failed to cut off as scheduled and fired until all of its propellant was exhausted, due to an erroneous ground command sent to the timer. This put the spacecraft on a trajectory to miss the Moon. The spacecraft was put through all the motions of an actual landing, jettisoning the lander and deploying the airbags, as an apparently successful practice run for the ground crew despite the fact that it flew by the Moon at a distance of 161,000 km on 11 June. Contact was lost at a distance of 600,000 km from Earth, the spacecraft presumably entering a heliocentric orbit.
Lunar soft landing attempt. The Luna 7 spacecraft was intended to achieve a soft landing on the Moon. However, due to loss of attitude control during the final approach to the lunar surface, the retrorockets were prevented from firing to slow the spacecraft and it impacted the lunar surface at 9.8 N, 47.8 W in the Sea of Storms on 7 October 1965 at 22:08:24 UT.
Lunar soft landing attempt failed. Luna 8's objectives were to test a soft lunar landing system and scientific research. Weighing 1,552 kg (3,422 lbs), the spacecraft was following a trajectory close to the calculated one and the equipment was functioning normally. However, a puncture to a cushioning airbag caused the spacecraft to spin, losing attitude control and preventing full firing of the retrorockets. The spacecraft impacted the lunar surface at 9.1 N, 63.3 W in the Sea of Storms at 21:51:30 UT on 6 December 1965. The mission did complete the experimental development of the star-orientation system and ground control of radio equipment, flight trajectory, and other instrumentation.
Soft landed on Moon; photographed surface for 3 days. Landed on Moon 3 February 1966 at 18:44:52 GMT, Latitude 7.08 N, Longitude 295.63 E - Oceanus Procellarum. The Luna 9 spacecraft was the first spacecraft to achieve a lunar soft landing and to transmit photographic data to Earth. Seven radio sessions, totaling 8 hours and 5 minutes, were transmitted as were three series of TV pictures. When assembled, the photographs provided a panoramic view of the nearby lunar surface. The pictures included views of nearby rocks and of the horizon 1.4 Km away from the spacecraft.
Lunar Orbit (Selenocentric). Development of system to permit the creation of an artificial lunar satellite for the investigation of circumlunar space; development of onboard systems for putting a station into a selenocentric (circumlunar) orbit. Orbit: Lunar Orbiter. The Luna 10 spacecraft was launched towards the Moon from an Earth orbiting platform. The spacecraft entered lunar orbit 3 50 x 1017 km, inclination 71.9 deg to plane of the lunar equator. on April 4, 1966. Scientific instruments included a gamma-ray spectrometer for energies between 0.3--3 MeV, a triaxial magnetometer, a meteorite detector, instruments for solar-plasma studies, and devices for measuring infrared emissions from the Moon and radiation conditions of the lunar environment. Gravitational studies were also conducted. The spacecraft played back to Earth the `Internationale' during the Twenty-third Congress of the Communist Party of the Soviet Union. Luna 10 was battery powered and operated for 460 lunar orbits and 219 active data transmissions before radio signals were discontinued on May 30, 1966.
Automatic station Luna 11. Further development of artificial lunar satellite systems and conduct of scientific experiments in circumlunar space. Lunar orbit 160 km x 1200 km x 27 degrees. Luna 11 was launched towards the Moon from an earth-orbiting platform and entered lunar orbit on August 28, 1966. The objectives of the mission included the study of: (1) lunar gamma- and X-ray emissions in order to determine the Moon's chemical composition; (2) lunar gravitational anomalies; (3) the concentration of meteorite streams near the Moon; and, (4) the intensity of hard corpuscular radiation near the Moon. A total of 137 radio transmissions and 277 orbits of the Moon were completed before the batteries failed on October 1, 1966.
Lunar Orbiter, further development of artificial lunar satellite systems and conduct of scientific experiments in circumlunar space. Luna 12 was launched towards the Moon from an earth-orbiting platform and achieved a lunar orbit of of 100 km x 1740 km on October 25, 1966. The spacecraft was equipped with a television system that obtained and transmitted photographs of the lunar surface. The photographs contained 1100 scan lines with a maximum resolution of 14.9--19.8 m. Pictures of the lunar surface were returned on October 27, 1966. According to contemporary US intelligence sources, only four pictures were returned. Radio transmissions from Luna 12 ceased on January 19, 1967, after 602 lunar orbits and 302 radio transmissions.
Soft landed on Moon 24 December 1966 at 18:01:00 GMT, Latitude 18.87 N, 297.95 E - Oceanus Procellarum. The petal encasement of the spacecraft was opened, antennas were erected, and radio transmissions to Earth began four minutes after the landing. On December 25 and 26, 1966, the spacecraft television system transmitted panoramas of the nearby lunar landscape at different sun angles. Each panorama required approximately 100 minutes to transmit. The spacecraft was equipped with a mechanical soil-measuring penetrometer, a dynamograph, and a radiation densitometer for obtaining data on the mechanical and physical properties and the cosmic-ray reflectivity of the lunar surface. It is believed that transmissions from the spacecraft ceased before the end of December 1966.
VVS Party Conference. It is clear to Kamanin that there is no support from the Air Force for manned spaceflight. Kamanin only heard yesterday that Babakin is working on an automatic soil sample return spacecraft. He will need a minimum of two to three years to complete it. Kamanin complained that it would interfere with plans for the L1 program. An uninterrupted series of flights will be needed to complete the L1 spacecraft qualification, and the Ye-8, using the same booster, could be an interference in achieving that goal.
Meeting of the VPK Military-Industrial Commission to discuss how to beat the Americans to the lunar landing Ustinov called the meeting to order. Mishin was 'sick' again -- Okhapkin represented TsKBEM and gave a summary of the programme to that date:
Keldysh proposed that further work on the L1 be abandoned, and Proton boosters instead be used to launch the Ye-8-5 lunar soil return robot spacecraft being developed by Babakin. Babakin had been accelerating this programme since the beginning of 1968 with the support of Keldysh, even though it would only return around 100 g of lunar soil, versus the tens of kilograms the Apollo manned flights would return. However it now offered an interesting possibility - he proposed obtaining lunar soil and returning it to earth before an American manned landing. The government's organs of mass communication would say that the Soviet Union's lunar program only consisted of robot probes, emphasising that his was much safer and that Russia would never risk it's citizen's lives for mere political sensation. Additional Details: here....
The head of the launch commission for Venera-5 and 6 says that will work on the Ye-8 and Ye-8-5 robot moon landers was making progress, it would be fantasy to believe that a moon landing and return to earth could be successfully accomplished in 1969. Venera was 'no answer' to Apollo at all. Meanwhile, he was worried about Soyuz landing in the Aral Sea in the event of problems during re-entry. Kustanin remembers times in the past when supposedly 'waterproof' spacecraft had landed in water. One Soyuz had splashed down in the Aral Sea, and one Zenit spysat in the Volga River. Both sank easily. But the chances of either Soyuz 4 or 5 landing in the Aral Sea were assessed as only 0.003. In any cases 5 helicopters and 3 Be-12 seaplanes were on standby to recover the crew in such an eventuality.
America is preparing Apollo 9 for flight, and Kamanin muses that the Soviet reply will be the N1 and Ye-8-5, neither of which is proven or reliable. The Soviet Union would have a better chance of sending a manned L1 on a flight around the moon during the first quarter of 1969. Meanwhile Mishin's bureau has a new L3M lunar lander on the drawing boards. This will land 4 to 5 men on the moon, but require two N1 or seven UR-500K launches to assemble in orbit.
Kamanin arrives at Tyuratam at 15:30 aboard an An-24. The State Commission for the first Ye-8 robot lunar rover mission is chaired by Tyulin at Area 31. The spacecraft will make a soft landing on the moon, deploy a mobile lunar rover that can traverse slopes up to 30 degrees. The rover will find a position that is clear of obstacles for the first Soviet manned lunar landing. It will then park there, and provide a landing beacon for the LK manned lander. The spacecraft will have a mass of 1700 kg in lunar orbit. Launch is set for 19-20 February.
At Area 81 a State Commission is held on failures of the UR-500K booster. A D Konopatov describes the analysis of the stage 2 and 3 failures on the 20 January launch attempt. The number 4 engine of stage 2 shut down 25 seconds into its burn due to high temperatures detected in the turbopump. The same thing occurred on the third stage. The couldn't pin down the source of the problem. Engines of this type had worked correctly 700 times on earlier flights. Despite the cause of the failure not being identified, approval is given at 14:30 for the launch of the Ye-8 to proceed. Babakin confirms the spacecraft is ready.
The Ye-8 and N1 are on schedule for their respective launches. Kamanin discusses the cosmonaut training curriculum with Kerimov. No one has ever defined what it is cosmonauts are actually supposed to do in space. No one really knows what their purpose is --- not Keldysh, not Mishin, not Smirnov, not Ustinov. Kerimov agrees to put together a state commission to define the role of man in space and draw up plans for future space missions.
Attempted launch of a Ye-8 with a Lunokhod lunar rover. Evidently coordinate in some way with the N1 launch two days later. A first-stage booster engine failure causes the rocket to crash 15 km from the pad after a lift-off at 09:48 local time. Kamanin meanwhile has the Hong Kong flu.
Keldysh first revealed the new 'party line' at a press conference on the semi-successful Venera 5 landing on Venus. When asked about Soviet lunar plans, he revealed that Russia would only use robot probes, that it wouldn't risk men's lives in such an endeavour. At the same time Babakin was hard at work finishing the first Ye-8-5 robot lunar soil return spacecraft, to be launched before Apollo 11.
The VPK Military-Industrial Commission issues a decree on the schedule for the rest of 1969. There are to be five launches of Ye-8-5 lunar soil return robots, on 14 June, 13 and 28 July, 25 August, and 25 September. There are to be two launches of Ye-8 Lunokhod robot rovers on 22 October and 21 November. Further manned L1 flights are cancelled. There are no plans made for the L3 since the N1 is not ready.
Another attempt to launch a Ye-8-5 to return lunar soil to the earth, 'scooping', the Americans' impending Apollo 11 mission. Yet another UR-500K launch failure. This time the UR-500K booster functioned perfectly, but the Block D upper stage did not fire, and the payload did not even attain earth orbit. Every UR-500K launch is costing the Soviet state 100 million roubles. This failure pretty much ended the chances for the Russians to trump the American moon landing. Tass yesterday began running stories to prepare the masses for the upcoming Apollo 11 triumph. The party line is that the Soviet Union is not about to risks the lives of its cosmonauts on flights to the moon, when automated probes can safely retrieve soil from the moon for study on earth. Additional Details: here....
Unmanned soil return mission launched coincident with Apollo 11 mission in last ditch attempt to return lunar soil to earth before United States. After completing 86 communications sessions and 52 orbits of the Moon at various inclinations and altitudes, crashed on the moon on 20 July in an attempted landing. Altitude data used in programming inaccurate or guidance system unable to cope with effect of lunar mascons.
Officially: Testing of on-board systems of the automatic station and further scientific investigation of the moon and circumlunar space. Parameters are for lunar orbit.
It is felt the problems are understood and go-ahead is given for the next lunar soil return robot launch attempt on 23 September. Kamanin considers this very unlikely to be successful -- all of the plans for automated spacecraft and their booster rockets have not been realised to date.
VPK Deputy Chairman Tyulin headed a state commission on the L1 programme. Mishin pushed for a manned L1 circumlunar flight in 1970. This meeting was only five days before a Ye-8-5 robot spacecraft was to have returned lunar soil from the earth. The Block D stage failed in earth orbit, and the flight was given the cover name Cosmos 300. This indicated the L1 system still did not have the necessary reliability for manned flight. Furthermore, politically, Brezhnev and the Politburo did not want to see a Khrushchev-originated project like the L1 succeed.
To ensure the buses do not exceed 60 km/hour checkpoints are manned along the roads. The readiness review is conducted form 10:00 to 13:00. The crews, and spacecraft are ready. Mishin is away 'sick' again. General Pushkin and Beregovoi are at Area 81 to view the Ye-8-5 launch. Kamanin likes Chelomei's UR-500K rocket. He blames its series of failures on its engines and Block D upper stage, not on the fundamental booster design. If it had been more successful, the Russians would have beaten the Americans in a lunar flyby. The launch proceeds as planned at 15:00, but the Block D fails to restart in parking orbit, and is given the cover name 'Cosmos 300'.
The cause of the Ye-8-5 failure is found to be a valve that was stuck open after the first stage burn, resulting in the oxidiser boiling away in the vacuum of space. Tyulin inquires about the possibility of commanding the Ye-8-5 to conduct a series of manoeuvres and testing re-entry of the soil return capsule in the earth's atmosphere. An interesting concept, but the engineers have not planned for such an eventuality.
NII-2 MO, represented by Lt General Korolev and Chief Designer Savin present plans for their Svinets experiment. It will observe ICBM rocket plumes from space in order to aid design of anti-ballistic missile systems. They had asked Smirnov to conduct a solid propellant rocket launch in order to test the device properly, but he could only schedule a liquid propellant rocket launch. Kamanin had wanted this experiment to be conducted aboard Voskhod 3, but Smirnov has cancelled that mission as well - delaying Soviet ABM development, in Kamanin's view.
Attempted test flight of Block D upper stage in N1 lunar crasher configuration. Payload was a modified Soyuz 7K-L1 circumlunar spacecraft, which provided guidance to the Block D and was equipped with television cameras that viewed the behavior of the Block D stage propellants under zero-G conditions. Mission flown successfully over a year later as Cosmos 382.
Lunar Sample Return. Landed on Moon 20 September 1970 at 05:18:00 GMT, Latitude 0.68 S, Longitude 56.30 E - Mare Fecunditatis. Luna 16 was launched toward the Moon from a preliminary earth orbit and entered a lunar orbit on September 17, 1970. On September 20, the spacecraft soft landed on the lunar surface as planned. The spacecraft was equipped with an extendable arm with a drilling rig for the collection of a lunar soil sample. After 26 hours and 25 minutes on the lunar surface, the ascent stage, with a hermetically sealed soil sample container, left the lunar surface carrying 100 grams of collected material. It landed in the Soviet Union on September 24, 1970. The lower stage of Luna 16 remained on the lunar surface and continued transmission of lunar temperature and radiation data. Parameters are for lunar orbit.
Luna 16 first placed itself into a 106 x 15 km lunar orbit, inclination 71 degrees. After the trajectory was measured and calculations made on earth, it was instructed to make its Phase 1 descent using a timed burn. Phase 2 began at 600 m altitude. From this point the new-design braking rocket was controlled automatically according to height and velocity as measured by radar. At 220 m altitude the main engine shut down, and small braking rockets fired. These were shut down just 2 m above the surface. At 08:18 Luna 16 successfully made a soft landing on the moon. Getting there required 68 communications sessions over nine days of flight. At 10:00 the drill obtains the soil sample and inserts it into the return capsule.
At 10:43 the Luna 16 ascent stage fires, thrusting the return capsule with the lunar soil toward the earth. It will land somewhere on Soviet territory within a 1500 km radius of Dzhezkazgan. The 25 cm diameter capsule is equipped with a 10 square meter parachute. It was thought that it would take 10 to 15 launches to perfect this system, but instead it has succeeded on the sixth attempt.
Luna 17 was launched from an earth parking orbit towards the Moon and entered lunar orbit on November 15, 1970. Luna 17 landed on Moon 17 November 1970 at 03:47:00 GMT, Latitude 38.28 N, Longitude 325.00 E - Mare Imbrium (Sea of Rains). The payload, the Lunokhod 1 unmanned rover, rolled down a ramp from the landing stage and began exploring the surface. Lunokhod was intended to operate through three lunar days but actually operated for eleven lunar days (earth months). The operations of Lunokhod officially ceased on October 4, 1971, the anniversary of Sputnik 1. By then it had traveled 10,540 m and had transmitted more than 20,000 TV pictures and more than 200 TV panoramas. It had also conducted more than 500 lunar soil tests. Parameters are for lunar orbit.
Shatalov is actively pushing his candidacy for the position of Kamanin's deputy. Popovich and Sevastyanov prepare for a trip to the Paris Air how on 2 June. They need 'correct' replies to inevitable questions about the moon race, the Salyut 1 station, and Soyuz 10's failure to dock. The line they are to follow is that the Soviet Union is fulfilling its safe and systematic exploration of space. The robots Luna-16 and Lunokhod 1 safely surveyed the moon. After the Soyuz 9 long-duration flight, Salyut 1 was launched and Soyuz 10 tested the rendezvous equipment. The line is that the USSR is not behind the USA, but is exploring space in a safe and responsible way.
Attempted lunar soil return mission; crashed while attempting to soft land at Latitude 3.57 N, Longitude 50.50 E - Mare Fecunditatis. Luna 18 used a new method of navigation in lunar orbit and for landing. The spacecraft's designer, Babakhin, had died at age 56 only the month before. Luna 18 successfully reached earth parking orbit before being put on a translunar trajectory. On September 7, 1971, it entered lunar orbit. The spacecraft completed 85 communications sessions and 54 lunar orbits before it was sent towards the lunar surface by use of braking rockets. It impacted the Moon on September 11, 1971, in a rugged mountainous terrain. Signals ceased at the moment of impact. Parameters are for lunar orbit.
Heavy lunar Orbiter; conducted lunar surface mapping. Luna 19 entered an intermediate earth parking orbit and was then put on a translunar trajectory by the Proton Block D stage. It entered lunar orbit on October 3, 1971. Luna 19 extended the systematic study of lunar gravitational fields and location of mascons (mass concentrations). It also studied the lunar radiation environment, the gamma-active lunar surface, and the solar wind. Photographic coverage via a television system was also obtained. Parameters are for lunar orbit.
Soft landed on Moon; returned soil samples to Earth. Landed on Moon 21 February 1972 at 19:19:00 GMT, Latitude 3.57 N, Longitude 56.50 E - Mare Fecunditatis. Luna 20 was placed in an intermediate earth parking orbit and from this orbit was sent towards the Moon. It entered lunar orbit on February 18, 1972. On 21 February 1972, Luna 20 soft landed on the Moon in a mountainous area known as the Apollonius highlands, 120 km from where Luna 18 had crashed. While on the lunar surface, the panoramic television system was operated. Lunar samples were obtained by means of an extendable drilling apparatus. The ascent stage of Luna 20 was launched from the lunar surface on 22 February 1972 carrying 30 grams of collected lunar samples in a sealed capsule. It landed in the Soviet Union on 25 February 1972. The lunar samples were recovered the following day.
The Proton / Block D launcher put the spacecraft into Earth parking orbit followed by translunar injection. On 12 January 1973, Luna 21 braked into a 90 x 100 km orbit about the Moon. On 13 and 14 January, the perilune was lowered to 16 km altitude. On 15 January after 40 orbits, the braking rocket was fired at 16 km altitude, and the craft went into free fall. At an altitude of 750 meters the main thrusters began firing, slowing the fall until a height of 22 meters was reached. At this point the main thrusters shut down and the secondary thrusters ignited, slowing the fall until the lander was 1.5 meters above the surface, where the engine was cut off. Landing occurred at 23:35 GMT in LeMonnier crater at 25.85 degrees N, 30.45 degrees E. The lander carried a bas relief of Lenin and the Soviet coat-of-arms. After landing, Lunokhod 2 took TV images of the surrounding area, then rolled down a ramp to the surface at 01:14 GMT on 16 January and took pictures of the Luna 21 lander and landing site. It stopped and charged batteries until 18 January, took more images of the lander and landing site, and then set out over the Moon. The rover would run during the lunar day, stopping occasionally to recharge its batteries via the solar panels. At night the rover would hibernate until the next sunrise, heated by the radioactive source. Lunokhod 2 operated for about 4 months, covered 37 km of terrain including hilly upland areas and rilles, and sent back 86 panoramic images and over 80,000 TV pictures. Many mechanical tests of the surface, laser ranging measurements, and other experiments were completed during this time. On June 4 it was announced that the program was completed, leading to speculation that the vehicle probably failed in mid-May or could not be revived after the lunar night of May-June. The Lunokhod was not left in a position such that the laser retroreflector could be used, indicating that the failure may have happened suddenly.
Heavy lunar orbiter. Scientific investigation of the moon and circumlunar space from the orbit of an artificial satellite of the Moon, which was begun by the Luna 19 automatic station. The spacecraft carried imaging cameras and also had the objectives of studying the Moon's magnetic field, surface gamma ray emissions and composition of lunar surface rocks, and the gravitational field, as well as micrometeoroids and cosmic rays. Luna 22 braked into a circular lunar orbit on 2 June 1974. The spacecraft made many orbit adjustments over its 18 month lifetime in order to optimise the operation of various experiments, lowering the perilune to as low as 25 km. Manoeuvring fuel was exhausted on 2 September and the mission was ended in early November. Parameters are for lunar orbit.
Failed lunar soil return mission. After successfully entering earth orbit, flying to the moon, entering lunar orbit, and descending toward the surface, the spacecraft was damaged during landing in Mare Crisium (Sea of Crises). The sample collecting apparatus could not operate and no samples were returned. The lander continued transmissions for three days after landing. In 1976, Luna 24 landed several hundred meters away and successfully returned samples. Parameters are for lunar orbit.
Lunar Sample Return. Landed on Moon 18 Aug 1976 at 02:00:00 GMT, Latitude 12.25 N, Longitude 62.20 E - Mare Crisium (Sea of Crisis). The last of the Luna series of spacecraft, Luna 24 was the third Soviet mission to retrieve lunar ground samples (the first two were returned by Luna 16 and 20). The mission successfully returned 170 grams of lunar samples to the Earth on 22 August 1976.