Category Soviet and Russian Lunar Exploration

DESIGNING A LUNAR ROVER

Although the Lunokhod was portrayed by the Soviet Union as a safer, cheaper alternative to the manned Apollo missions, in fact the Lunokhod long pre-dated Apollo. Originally, Lunokhod was an integral part of the manned Russian lunar programme. Moon rovers were to pave the way for manned landings by surveying sites before cosmonauts landed, the L-2 programme. They would leave beacons to guide the LK landing ships in. Later, bigger rovers would be landed and cosmonauts were expected to ride them across the moon (the L-5 programme).

The moon rover was originally designed in Korolev’s OKB-1. The preliminary studies were done by Mikhail Tikhonravov in I960. When the Americans first landed a rover on Mars, the Sojourner (1997), it was tiny. By contrast and in typical Soviet style, the Russians started large. Korolev’s team determined that the rover should be at least 600 kg, the size of a small car. This would require a launcher much larger than the Molniya then in design, so Korolev made it a candidate for an early version of the N-1 rocket. Korolev issued the order for the construction of a moon rover in March 1963, but the project progressed slowly and was set back when later that year the state Institute for Tractor and Agricultural Machinery Building declined to develop it, deeming the project to be ‘impossible’.

So, later in 1963, Sergei Korolev instead turned to VNII-100 Transmash of Leningrad, or the Mobile Vehicle Engineering Unit [3]. In September of that year, Korolev met with VNII Transmash engineers to go through the possibilities.

DESIGNING A LUNAR ROVER

Alexander Kemurdzhian

Transmash designed tanks for the Red Army – indeed, during the siege of Stalingrad, tanks were sometimes rolled out of the factory straight up to the front line. The important role of Alexander Kemurdzhian in the Soviet lunar programme emerged only in recent years. He was born on 4th October 1921 in Vladikavkaz and entered the Bauman Technological College in Moscow in 1940. When the war broke out, he went to Leningrad Artillery College and participated in some of the epic battles of the war, such as the crossing of the Dniepr. After the war, he worked on truck design, specializing in transmission systems, for which he obtained a doctorate in 1957. Two years later, he moved into the new area of air cushion vehicles (hovercraft). Kemurdzhian had a personal interest in spaceflight (something he made dear to Korolev) and saw the potential for remote-controlled vehicles exploring the planets. The rover project was no sideshow, for in 1964 it won approval – as the L-2 programme – in the 1964 government and party resolution committing the Soviet Union to going to the moon.

The conceptual study was completed in six months, by April 1964. One of the first problems faced by the designers was the load-bearing capacity of the lunar soil, for this would govern chassis, power systems and wheel design. Until such time as soft – landers tested the surface, it would be impossible to know the answer for definite. In an attempt to make the best possible estimate, a conference of lunar and astro­nomical experts were gathered at Kharkov University that year, hosted by Professor Barabashev and also attended by Professor Troitsky of Gorky University and Pro­fessor Sharanov of Leningrad University. In the event, their estimates were broadly

DESIGNING A LUNAR ROVER

Moon rover on test

correct, being confirmed by Luna 13 two years later. First design sketches were concluded in September 1965.

The rover project was turned over, along with all the other unmanned lunar and interplanetary programmes, to OKB Lavochkin in 1965. Kemurdzhian worked closely with the director of OKB Lavochkin, Georgi Babakin, to finalize what was then called in 1966 the Ye-8. The Ye-8 was originally intended to pave the way for the manned lunar landing. Before the first Ye-8 landed, suitable sites would first be selected by a close-look lunar orbiter. To do this, a version of the rover was adapted for a photography mission in lunar orbit to select a main landing site for the lunar landing, but there was also a reserve one nearby, not more than 5 km distant. Two Ye-8s would then be landed, one at the main site, one at the reserve. These would confirm the suitability of both sites for the manned lunar landing. In an elaboration of the plan, an unmanned LK would be landed near the rover at the reserve site and checked out to see that it was in good working order. If when he landed his LK was disabled, the sole cosmonaut could travel to the reserve LK to return to Earth. In a further version, the cosmonaut could use the rover to travel across the lunar surface from the main site to the reserve site.

A number of designs using different numbers of wheels were considered in the course of 1965-6. The designers considered tractors, walkers and even jumpers, from caterpillar to four-wheel designs. The very first rover design was for a dome carried on four caterpillar wheels, very like a tank. The first rovers were designed to weigh nearly a tonne, about 900 kg. When it was apparent that the N-1 would not become quickly available, the Ye-8 was scaled down so that it could be accommodated within Chelomei’s UR-500K Proton. The final rover design was for an unmanned rover. In a further modification of the original plan, the Ye-8 would be launched before the Ye-8LS lunar orbiter, the opposite of what had been intended.

The rover design was settled in 1967 and a 150 kg scaled prototype was constructed in Leningrad that year. A version was tested in the volcanic region of Kamchatka in the Soviet far east, which was the Earth’s surface closest in character to the moon. Models were tested in the Crimea and early versions of the transmission gears and wheels were flown out to the moon on Luna 11 and 12 in 1966 and Luna 14 in 1968. Even though it had been scaled back, the final rover was still a substantial piece of engineering. The vehicle, to be called ‘Lunokhod’ or ‘moon walker’ in Russian, weighed 756 kg and was 4.42 m long (lid open), 2.15 m in diameter and 1.92m high. Its wheel base was 2.22 m by 1.6 m. The main container was a pressurized vehicle, looking like an upside down bathtub, carrying cameras, transmitters and scientific instruments. It was kept warm by a small decaying radioisotope of 11 kg of polonium-210. The eight 51 cm diameter wheels were made by the Kharkhov State Bicycle Plant, made of metal with a mesh covering. There was a ninth wheel behind the vehicle to measure distance. Each wheel had its own electric motor. In the event of one wheel becoming completely stuck, a small explosive charge could be fired to sever it. The vehicle was designed to climb slopes of 20° and manage side slopes of 40 to 45°. The main designers were, aside from Kermurdzhian himself, Gary Rogovsky, Pavel Sologub, Valery Gromov, Anatoli Mitskevich and Slava Mishkinjuk.

To guide the route chosen, Lunokhod had four 1.3 kg panoramic cameras similar to those on Luna 16 to scan 360° around the rover and two television cameras to scan forward, with a 50° field of view and 1/25 sec speed. The scan of the panoramic cameras was designed in such a way as to cover the horizon right around to parts of the rover and its wheel base. They provided high-resolution images, 6,000 x 500 pixels. Signals were sent back by both an omnidirectional and narrow-beam antenna. The driving camera relayed pictures back to Earth every 20 sec and these enabled a five-person ground crew to drive the Lunokhod: commander, driver, navigator, engineer and radio operator. The rover could go forwards or backwards. Gyroscopes would stop the rover if it appeared to tilt too much forward or backward or to one side.

The selection of the ground crew was an important part of the programme. Two five-man crews were selected from the Missile Defence Corps in 1968 [4]. Volunteers were sent for tests for speed-of-reaction times, short and long-term memory, vision, hearing and capacity for prolonged mental focus and attention. At one stage of their recruitment, they thought they were being trained as cosmonauts. They were under strict instructions not to talk about their work to outsiders. Years later, their names became known. They had been recruited by the Strategic Rocket Forces in the late 1960s when the call had gone out for ‘top class military engineers. Young but experienced. Sporting and in a good state of health.’ Twenty-five were chosen and sent to Moscow for a special mission, they did not know what. They were put through a series of tests in the Institute for Medical and Biological Problems, where the group was reduced by eight. Then, the seventeen remaining were told that they would be driving machines across the surface of the moon, whereupon three resigned, saying that the responsibility and stress would be too much for them. The fourteen remaining were divided: half were sent off to Leningrad to the VNII-100 design bureau where the Lunokhod was built and the other half were assigned to work on the design with the Lavochkin design bureau. In 1968, construction began of a ‘lunardrome’ in Simfer­opol in the Crimea, and the driving teams spent the rest of the year there learning how to drive a Lunokhod model.

Table 7.1. The Lunokhod operators

First crew

Second crew

Commander

Nikolai Yeremenko

Igor Fyodorov

Driver

Gabdulkay Latypov

Vyacheslav Dovgan

Navigator

Konstantin Davidovsky

Vikentiy Samal

Engineer

Leonid Mosenzov

Albert Kozhevnikov

Radio, antenna

Valeri Sapranov

Nikolai Kozlitin

Reserve

Vasili Chubukin

DESIGNING A LUNAR ROVER

Luna 17 descent stage

Lunokhod carried a number of scientific instruments: a French-built 3.7 kg laser reflector, designed to measure the precise distance between Earth and the moon; a RIFMA X-ray fluorescent spectrometer to determine the composition of moonrock; an X-ray telescope; a cosmic ray telescope; and a penetrometer. An energetic particle detector was built by Dr Yevgeni Chuchkov of the Theoretical and Applied Physics Divison of the Skobeltsyn Institute of Nuclear Physics of the Moscow State Univer­sity, calibrated against similar instruments flown on Zond 1 and 3 and the early Mars and Venera probes.

To get Lunokhod onto the lunar surface, the KT stage was used, of the same type as Luna 15 and 16. This was a frame-shaped spacecraft with a toroidal fuel tank; radar; attitude thrusters; 11D417 engine of between 0.75 and 1.92 tonnes of thrust for mid-course correction, lunar orbit insertion and landing; batteries; and communica­tions. The Lunokhod rested atop the descent stage, and – when the moment came – landing ramps would deploy at either side so the rover could descend to the moon at an angle of up to 45°.

Lunokhod instruments

Laser reflector.

RIFMA (Roentgen Isotopic Fluorescent Method of Analysis) X-ray fluorescent spectrometer. Extra-galactic X-ray telescope.

Cosmic ray background radiation detector.

PrOP (Pribori Ochenki Prokhodimosti) penetrometer.

Ultraviolet photometer (Lunokhod 2 only)

Any benefit that was gained by the success of Luna 16 was turned to double advantage just two months later by Luna 17. The sample return, pushed to the back page by the eruption of political violence in the Middle East, had made little public impact. The same could not be said of its successor, put up on 10th November 1970. The spaceship weighed about 5,750 kg.

Around the moon

The moon race between the Soviet Union and the United States climaxed in summer 1969 when the first men landed on the moon – but there was an earlier, dramatic climax six months earlier at Christmas 1968. That time the battle was to see which country would be the first to send people around the moon and return. Although, in retrospect, there was less and less chance that the Russians would beat the Americans to a moon landing, the chances of the Russians sending cosmonauts around the moon first were very real.

By late August 1968, the Russians were still trying to achieve a successful mission of the L-1 Zond around the moon. The continued troubles with the Proton rocket must have been deeply disappointing. It was then going through its most difficult phase of development and none could have imagined that it would become, much later on, one of the world’s most reliable rockets. Although L-1 Zond missions had started as far back as March 1967 with Cosmos 146, none since then had been entirely successful. In August 1968, the Russians began to realize that time was no longer on their side. The first manned Apollo, redesigned after the Apollo fire, was due to make its first flight in October. Word came out of Washington that NASA was considering sending the second Apollo around the moon before the end of the year. It would be only the second Apollo flight and the first crew on the huge Saturn V rocket. The Russians had considered four unmanned lunar flights as essential before a manned flight: now the Americans were planning a manned flight on only the second Apollo mission, without any unmanned flights around the moon first.

As luck would have it, the same launch window that might take Apollo 8 to the moon opened for America on 21st December but much earlier in the USSR – from 7th to 9th December. This was entirely due to the celestial mechanics of the optimum launching and landing opportunities.

MOONBASE ZVEZDA, 1974

The second moonbase proposal was the Zvezda one developed for Valentin Glushko by Ivan Prudnikov in 1974. The crew for the moon base would be brought there by a 31 tonne lunar expeditionary craft, or LEK in Russian. This would use direct ascent, not lunar orbit rendezvous. Once their lunar visit was complete, the three cosmonauts would blast home in their 9.2 tonne upper stage. The reentry vehicle was small, weighing 3.2 tonnes. The initial crew of the base would be three, but this would be doubled as more equipment was ferried up from Earth by Vulkan rockets. The total weight to be transported to the moon would, in the end, be around 130 tonnes, involving up to six Vulkans.

The moon base itself would have three elements: a habitation module, laboratory module and lunar rover. First, there would be a lunar habitation module, or LZhM in Russian. This was a non-returnable 21.5 tonne living and scientific area, 9 m tall, 8 m wide and with a volume of 160 m3. It would deploy solar panels able to generate 8 kW of electricity. Next was a laboratory production module, the LZM in Russian. Weighing 15.5 tonnes, this would stand 4.5m tall and have a volume of 100m3 for oxygen generation, biotechnology and physics experiments, operated by a single
cosmonaut at a time. As was the case with the Galaktika proposal, a lunar rover was an essential element. The Lunokhod would measure 4.5m wide, 8 m long and 3.5 m high, weigh 8.2 tonnes and could transport two cosmonauts up to 200 km distant at a speed of up to 5 km/hr. The rover would be able to drive on expeditions for up to twelve days at a time (a full lunar day), carrying drilling and other scientific equipment.

Подпись: Russia’s moon plans 1964-71 N1-L3 1972-4 N1-L3M 1974-6 Vulkan
Подпись: Korolev and Mishin Mishin Glushko

Valentin Glushko did not give up easily and attempted to resurrect it as Zvezda II in the 1980s. It was a scaled-down proposal, using two Energiya rockets rather than the much larger Vulkan [3]. Designed along lines similar to the N1-L3M plan of his deposed rival Vasili Mishin, two Energiyas would place a 74-tonne complex with five cosmonauts on board into lunar orbit. Three would descend to the surface for a twelve-day surface stay. Preliminary designs of the Zvezda II mothership and lander were done, both being significantly larger than the LOK and the LK. However, even Glushko must have realized that there was no prospect, at this time, that they would receive serious consideration.

Russia’s

moon base plans

1967-70

Galaktika

1974-6

Zvezda

1986

Zvezda II

Barmin

Glushko and Prudnikov Glushko

NOW FOR LUNAR ORBIT

Orbiting the moon was as essential to a manned mission as a soft-landing. Good photographs were essential to determine landing sites and it was important to learn as much as possible about the lunar orbit environment to ensure there were no nasty surprises (there were).

The Soviet lunar orbiter programme was commissioned by OKB-1 at the same time as the Ye-6 programme. Called the Ye-7 programme, it made very slow progress in comparison. Two partially completed Ye-7 models were turned over by OKB-1 to OKB Lavochkin in summer 1965 during the move between the design bureaux. After the success of Luna 9, attention focused on the lunar-orbiting missions.

NOW FOR LUNAR ORBIT

Luna 10

Although the Ye-7 photographic equipment was not ready, Russia still wanted to achieve a lunar orbit before the Americans did so with their upcoming lunar orbiter. There was also political pressure to mark the 23rd Communist Party Congress, opening at the end of March 1966 and the first congress of new Soviet leader Leonid Brezhnev. Georgi Babakin and Mstislav Keldysh proposed that the Ye-6 bus be used to fly a lunar orbit mission in time for the congress.

This hastily conceived lunar orbiter was called the Ye-6S. It used the Ye-6 bus, to which was attached not the normal lander, but a pressurized 245 kg cabin that would serve as a lunar orbiter. It is more than likely that the cabin was taken from what would have been an Earth-orbiting satellite in the Cosmos series. Its shape strongly suggests that it may have been one of the Cosmos series built by Mikhail Yangel’s design bureau in Dnepropetrovsk. It was equipped with seven scientific instruments originally planned for the Ye-7, including a magnetometer on a long boom. From the ground, scientists would also measure gases in the lunar environment by examining signal strengths as the probe appeared and reappeared behind the lunar limb, and watch for changes in the orbit due to the lunar gravitational field. Lunar orbit insertion would be performed by the Ye-6 bus. Instead of a 46 sec burn for soft – landing, a much smaller burn was required for orbit insertion. Once in orbit, the pressurized Cosmos cabin would separate for an independent mission.

The first Ye-6S was launched on 1st March 1966. The upper-stage problems reasserted themselves and block L failed to fire the probe – renamed Cosmos 111 — out of Earth orbit. The second Ye-6S eventually got away on 31st March 1966. No sooner was it streaking towards the moon than it was announced that it was directed towards an entirely new objective — lunar orbit. Eight thousand kilometers from the moon, Luna 10 was turned around in its path and its rockets blazed briefly but effectively. They knocked 0.64km/sec off its speed, just enough to let it be captured by the moon’s gravity field. The boiler-shaped instrument cabin separated on schedule 20 sec later. Luna 10 was pulled into an orbit of 349 by 1,015 km, 71.9°, 2 hr 58 min and became the first spacecraft to orbit the moon.

But, first things first, Luna 10 celebrated the latest Russian achievement in style. Celestial mechanics meant that Luna 10 would enter the first of its lunar orbits just as the Communist Party was assembling in Moscow for its morning congress session. As it rounded the eastern edge of the moon, Luna 10’s transmitter went full on and relayed the bars of the Internationale — in turn, broadcast live by loudspeaker direct to the party congress over the static of deep space. It was a triumphant moment and the 5,000 delegates had good reason to stand and cheer wildly. Thirty years later, it was learned that the ‘live’ broadcast was actually a prerecording taken from Luna 10 earlier in the mission. The radio engineers did not trust the live broadcast to work, but, as they later admitted, playing tricks on the Central Committee was a dangerous game and the truth could only be safely revealed in the 1990s when the Central Committee itself was no more.

Luna 10’s mission lasted way into the summer and did not end till 30th May after 56 days, 460 lunar revolutions and 219 communication sessions. Data were trans­mitted on 183 MHz aerials and also on 922 MHz aerials. A stream of data was sent back by its magnetometer, gamma ray spectrometer, infrared radiometer, cosmic ray detector and meteoroid counter. These found a very weak magnetic field around the moon, 0.001% that of Earth (probably a distortion of the interplanetary magnetic field); no lunar magnetic poles; cosmic radiation at 5 particles/cm2/sec; 198 meteoroid impacts, more in lunar orbit than in the flight to the moon; no gaseous atmosphere; and that there were anomalous zones of mass concentrations below the lunar surface disturbing the lunar orbit (mascons). Using its gamma ray spectrometer, Luna 10 began the first initial survey of the chemistry of the moon, enabling a preliminary map to be compiled. Lunar rocks gave a composition signature broadly similar to basalt, but other important clues to its composition were picked out. The gamma ray spec­trometer was used to measure the level of uranium, thorium and potassium in lunar rock. There were significant variations in radiation levels on the moon, being high in

Подпись: Luna 10 enters lunar orbit

the Sea of Clouds, for example. Luna 10’s magnetometer was put on the end of a 1.5 m boom and took measurements every 128 sec for two months. Designer Shmaia Dolginov – who had built the original magnetometer on the First Cosmic Ship – was able to refine the range to between —50 and +50 gammas.

Подпись: Ye-6S Height Base Weight (payload) Orbiting altitude Plane
Подпись: 1.5m 75 cm 245 kg 350 x 1,000 km 71.9°

Luna 10’s final orbit, as measured on 31st May, was 378-985 km, 72.2° – whether the changes were due to mascons or reflect more accurate measurement of the original orbit is not certain. Despite its hasty assembly, the Dnepropetrovsk Cosmos mission had presented a significant haul of science, significantly advancing the knowledge of the moon in only a couple of months.

Luna 10 instruments

Meteorite particle recorder. Gamma spectrometer. Magnetometer with three channels. Solar plasma experiment.

Infrared recorder.

Radiation detector.

Charged particle detector.

Подпись: Luna 10 cabin

The discoveries of Luna 10

Weak magnetic field around the moon, 0.001%.

No lunar magnetic poles.

Cosmic radiation in lunar orbit.

Meteoroid impacts, more in lunar orbit than in the flight to the moon. No gaseous atmosphere.

Mascons.

Basaltic surface composition.

WINDING DOWN THE L-l ZOND AROUND-THE-MOON PROGRAMME

Even though Apollo 8 had flown around the moon in December 1968, the L-1 programme was not abandoned. There were several reasons. The hardware had been built or was still in construction. So much investment had gone into the programme that it was felt better to test out the technical concepts involved than write them off altogether and deny oneself the benefits of the design work. If these tests went well, a manned moon circumlunar mission could still be kept open as an option. Indeed, with some of the political pressure lifted, designers looked forward to testing their equip­ment without the enforced haste required by American deadlines. There was also an official problem, bizarre to outsiders, which was that the Soviet government lacked a mechanism to stop the moon programme. At governmental level, no one was yet prepared to admit failure or to take responsibility for what had gone wrong [10]. The resolutions of August 1964 and February 1967 remained in effect, unrepealed. According to Alexei Leonov, the government decided that if the next Zond succeeded, then the following one would be a manned flight, even after Apollo 8.

A new Zond was readied in January and left the pad on 20th January 1969. It is unclear what profile it would have flown, for it was outside the normal launch window. The cabin used was the one salvaged from the April 1968 failure [11]. The second stage shut down 25 sec early at 313 sec, but the other second-stage engines completed the burn. During third-stage firing, the fuel pipeline broke down and the main engine switched off at 500 sec, triggering a full abort. The emergency system lifted the Zond cabin to safety, and it was later retrieved from a deep valley near the Mongolian border. As we know, the period January to July 1969 lacked good launch-and-return windows for Zond missions around the moon, so any missions would have to be performed either under less than ideal tracking, transit or lighting conditions, or would have to be fired at a simulated moon, which was probably the case this time.

There were still Zond spacecraft available. At this stage, a perfect circumlunar flight was still required before a manned mission could be contemplated. However, a Russian manned circumlunar flight would now, after Apollo 11, make an even more

WINDING DOWN THE L-l ZOND AROUND-THE-MOON PROGRAMME

A full Earth for Zond 7

invidious comparison after Apollo 8. The chances that the cosmonauts would be allowed to fly were fading.

The Russians took advantage of the first of the new series of lunar opportunities opening in the autumn. Zond 7 left Baikonour on 8th August 1969, only two weeks after Luna 15’s demise and at about the time that the Apollo 11 astronauts were emerging from their biological isolation after their moon flight. Thirty turtles had been ready for the mission and four were selected. Zond 7 was the only one of the series to carry colour cameras. Cameras whirred as Zond skimmed past the Ocean of Storms and swung round the western lunar farside 2,000 km over the Leibnitz Mountains. Zond 7 carried a different camera from its predecessors, a 300 mm camera with colour film taking 5.6 cm2 images. Strikingly beautiful colour pictures were taken

of the Earth’s full globe over the moon’s surface as Zond came around the back of the moon. Like Zond 5, voice transmissions were sent on the way back. Zond 7 headed back to the Earth, skipped like a pebble across the atmosphere to soft land in the summer fields of Kustanai in Kazakhstan after 138 hr 25 min. It was a textbook mission.

How easy it all seemed now. After the total success of Zond 7, plans for a manned circumlunar mission were revived and there were still four more Zond spacecraft in the construction shop – one even turned up in subsequent pictures with ‘Zond 9’ painted in red on the side. The state commission responsible for the L-1 Zond programme met on 19th September and the decision was taken to fly Zond 8 as a final rehearsal around the moon in December 1969, with a manned mission to mark the centenary of Lenin’s birth in April 1970, which would be a big national event.

This plan, which was probably designed to appeal to the political leadership, did not in fact win government approval. There were mixed opinions among those administering the Soviet space programme as to whether a man-around-the-moon programme should still fly. Many had serious reservations about flying a mission that would be visibly far inferior not only to Apollo 11 but to the two Apollo lunar – orbiting flights that preceded it. Others disagreed, arguing that the Soviet Union would, by sending cosmonauts to the moon and back, demonstrate at least some form of parity with the United States. In 1970, few other manned spaceflights were in prospect, so a flight around the moon would at least boost morale. The normally cautious chief designer Vasili Mishin pressed hard for cosmonauts to make the lunar journey on the basis that the experience gained would be important in paving the way for a manned journey to a landing later. The political decision, though, was a final ‘no’, the compromise being that Mishin was allowed to fly one more Zond but without a crew. Two of the cosmonauts in the programme subsequently went on record to explain the decision. The political bosses were afraid of the risk that someone would be killed, said Oleg Makarov, who was slated for the mission. Another cosmonaut involved, Georgi Grechko, felt that the primary reason was political: there was no point in doing something the Americans had already done [12]. In the end, Lenin’s centenary was marked, indirectly and two months after the event, by the 18-day duration mission of Andrian Nikolayev and Vitally Sevastianov.

Zond 8 was eventually flown (20th-27th October 1970). It carried tortoises, flies, onions, wheat, barley and microbes and was the subject of new navigation tests. Astronomical telescopes photographed Zond as far as 300,000 km out from Earth to check its trajectory. Zond 8 came as close as 1,110 km over the northern hemisphere of the lunar surface, the closest of all the Zonds. Two sets of black-and-white images were taken, before and after approach. The 400 mm black-and-white camera of the type used on Zonds 5 and 6 was carried. These were high-density pictures, 8,000 by 6,000 pixels and are still some of the best close-up pictures of the moon ever taken [13].

There have been contradictory views as to whether Zond 8 was intended to return to the Soviet Union or be recovered in the Indian Ocean. The records now show that the recovery in the Indian Ocean was deliberate and not the result of a failure. As we know, the optimum trajectory for a returning Zond was to reenter over the southern hemisphere and make a skip reentry, coming down in the normal land recovery zone (Zond 6 and 7), or, if the skip failed, a ballistic descent into the Indian Ocean (Zond 5).

The alternative approach, one favoured by Mishin, was to come through reentry over the northern hemisphere, with good contact with the ground during this crucial period, but make a southern hemisphere splashdown. This route had not been tried before. Two Soviet writers of the period confirm that the purpose of Zond 8 was indeed ‘to make it possible to verify another landing version with deceleration over the USSR’ [14]. Zond 8 made a smooth northern hemisphere skip reentry and came down in the Indian Ocean 24 km from its pinpoint target where it was found within 15 min by the ship Taman. This seemed to prove Mishin’s point. Six years later, though, cosmonauts Vyacheslav Zudov and Valeri Rozhdestvensky splashed down in a lake and very nearly drowned during a protracted and hazardous recovery.

Analysis of the biological samples found similar results across the series. The turtles were hungry and thirsty after their return: hardly a surprise as they had not been fed or watered during their mission. They were examined for changes to their heart, vital organs and blood. There were some mutations in the seeds as a result of radiation. Overall, radiation dosages seemed to be well within acceptable limits, not posting a danger to cosmonauts and not significantly different from conditions in Earth orbit.

Thus, of nine Zond missions and of six attempts to fly to the moon, only Zond 7 and 8 were wholly successful. The last two production Zonds were never used. Just as the Russians tested their lunar hardware in Earth orbit successfully (Cosmos 379, 382, 398,434), they tested their round-the-moon hardware successfully. We now know that the Russians reached the stage where they could, with a reasonable prospect of success, have proceeded to a manned around-the-moon flight. Years later, Vasili Mishin was asked about his period as chief designer and whether he would have done things differently. ‘Perhaps,’ he said wistfully, ‘I would have insisted on making a loop around the moon, even after the United States, because we had everything ready for it. Maybe we could have done it even before the Americans’ [15].

L-l, Zond series

10 Mar 1967

Cosmos 146

8 Apr 1967

Cosmos 154 (failure)

28 Sep 1967

Launch failure

23 Nov 1967

Launch failure

2 Mar 1968

Zond 4

23 Apr 1968

Launch failure

22 Jul 1968

Pad accident

15 Sep 1968

Zond 5

14 Nov 1968

Zond 6

20 Jan 1969

Launch failure

8 Aug 1969

Zond 7

20 Oct 1970

Zond 8

L-l/Zond series: scientific outcomes

• Characterization of Earth-moon, moon-Earth space.

• Mapping of lunar farside.

• Acceptability of radiation limits for biological specimens.

THE SPACESHIP TO LAND ON THE MOON: THE LUNIY KORABL, LK

The descent of the Soviet lunar lander, called the LK (Luniy Korabl), to the lunar surface would be a steep one. The final lunar orbit would be 16 km by 85 km, the same as the final orbit of the later Ye-8-5 lunar sample return missions. Block D would fire at the 16 km perilune, bringing the LK to between 2 km altitude (maximum) and 500 m (minimum), ideally 1,500 m. If all went well, the LK pilot would set the LK down about 25 sec thereafter, but not more than a minute later. The LK would descend to 110 m, when it would hover: then the cosmonaut would take over for the landing. The instructors told the cosmonauts that at 110 m, they had three seconds to select a landing site, or return to orbit (‘as if returning at this stage was an option’, snorted Leonov). The standing cosmonaut, watching through his large, forward-looking window, would guide the LK lander with a control stick for attitude and rate of descent.

The engine, called block E, was designed by the Mikhail Yangel OKB-586 in Dnepropetrovsk. It was a well-equipped propulsion set. The LK module had:

• One 11D411 RD-858 main engine weighing 53 kg with a single nozzle with a specific impulse of 315 sec, chamber pressure of 80 atmospheres and duration of 470 sec.

• A 11D412 RD-859 57 kg backup engine with two nozzles.

• Four vernier engines.

• Two 40 kg thrusters for yaw.

• Two 40 kg thrusters for pitch.

• Four 10 kg thrusters for roll.

The descent and take-off engine was a throttlable, single-nozzle, 2.5-tonne rocket burning nitrogen tetroxide and UDMH. It could be throttled between 860 kg thrust and 2,000 kg. The engine held 1.58 tonnes of nitric acid and 810 kg of UDMH. The engine had four verniers to maintain stability. For attitude control during the nerve – wracking descent to the moon, eight low-thrust engines designed by the Stepanov Aviation Bureau fed off a common 100 kg propellant reserve. The system was both safe – it ran off two independent circuits – and sensitive, for thrust impulses could last as little as nine milliseconds. To land the LK, the cosmonaut had a computer-assisted set of controls, the first carried on a Soviet manned spacecraft. The S-330 computer was a sophisticated digital machine, linking the cosmonaut’s commands to the land­er’s gyroscopes, gyrostabilized platform and radio locator, with three independent channels working in parallel [18]. Four upward-firing solid rockets would ignite on landing, to press the LK onto the surface. The lander was designed to take a slope of 20°.

The LK was different from the Apollo lunar module (LM) in a number of important respects. These were a function of the much poorer lifting power of the N-1 rocket. First, it was much smaller, being only 5.5 m tall and weighing 5 tonnes (the LM was, by contrast, 7 m tall and weighed 16 tonnes). It had room for only one cosmonaut standing and the lower stage would have no room for the extensive range of scientific instruments carried by Apollo. Second, the LK had a single 2,050 kg thrust main engine which was used for both descent and take-off (Apollo’s LM had a descent motor and a separate one for the small upper stage). Like the LM, the LK would use the descent stage as a take-off frame. The LK was designed for independent flight of 72 hours and up to 48 hours on the lunar surface. The LK was a minimalist approach to a lunar landing. Although the method of landing on and take-off from the moon was broadly similar, there were some important differences:

• The American LM descent engine carried out the entire 12 min descent from PDI (powered descent initiation) to touchdown. By contrast, block D provided most of the thrust of the descent of the Soviet LK. Block D was dropped around 1,500 m above the surface and the LK’s descent stage took over for the final part.

• The American LM had two motors, one for descent and one for ascent. By contrast, the Russian LK had just one motor, which was used for descent and ascent.

What would the LOK-LK mission have been like? It would begin with the launching, from Baikonour Cosmodrome, of two cosmonauts on the N-1 rocket. The three stages

THE SPACESHIP TO LAND ON THE MOON: THE LUNIY KORABL, LK

The LK

of the N-1 rocket would burn until the lunar stack was safely in an Earth orbit of 51.6°, 200 km. At the end of the first parking orbit, the fourth stage, block G, would fire for translunar injection. This block would then separate.

Unlike Apollo, there would be no transposition, docking and ejection of the lunar module. This would remain behind the command ship, the LOK, as they headed moonward. On the way to the moon, the fifth stage, block D, would fire for a translunar correction. Three days into the mission, block D would fire the stack into lunar orbit. The descent from lunar orbit would again be different from Apollo. First, a lone cosmonaut would enter the lunar module, the LK. Because there was no internal hatch, the cosmonaut would exit the hatch and climb down the side of the LOK along a pole before entering the access hatch. This would take place against the backdrop of the moon’s surface below and the spectacle would be stunning. Once on board the LK, the cosmonaut would then separate his lunar module and block D from the LOK mother ship. Here would come a fresh difference. The powered descent

THE SPACESHIP TO LAND ON THE MOON: THE LUNIY KORABL, LK

LK hatch

THE SPACESHIP TO LAND ON THE MOON: THE LUNIY KORABL, LK

LK inside

THE SPACESHIP TO LAND ON THE MOON: THE LUNIY KORABL, LK

LK ladder

THE SPACESHIP TO LAND ON THE MOON: THE LUNIY KORABL, LK

LK window

burn would be done by block D. It would be jettisoned a mere 1,500 m above the lunar surface, leaving the LK’s main engine to complete the descent to the lunar surface. This would be the same engine used for take-off.

Hover time was much tighter on the Russian LK than the American LM. The Russians had about a minute to find the landing site and put the spacecraft down. The pilot could, of course, use more than 1 min, since it was the same engine used for the ascent, but this would eat into the thrust required for ascent. The LM had a longer hover time, about 2 min. By the end of the 2 min, the LM would be out of fuel and the mission would have to abort. Below a certain altitude, the period of time for firing the ascent stage would be longer than the time taken to fall to the surface, so the LM would crash (this was called ‘dead man’s handle’). All but one of the Apollos were sufficiently well targeted not to present a problem. The most difficult landing was the first, Apollo 11, which landed with only 19 sec of fuel to spare. ‘Dead man’s handle’ did not operate on the LK, since the engine used for the ascent was already firing. Arguably, it was safer. The LK lunar lander, like Apollo, had four legs. The first Soviet moon landing would have been shorter than that of Apollo 11, without a sleep period.

Once on the surface, the sole cosmonaut would carry out a spacewalk. We do not know how long the first lunar stay was planned. A moonwalk duration of four hours has been suggested, so the surface stay time would have to be long enough to report back after landing, prepare for the moonwalk, carry it out, return and prepare for take-off and rendezvous.

After several hours on the surface, the cosmonaut would lift off from the moon in the upper stage of the LK, and conduct the type of rendezvous pattern tested by Cosmos 186-188, 212-3 and Soyuz 2-3 and 4-5 in which the LOK orbiter performed the active role. A backup two-nozzle engine was also available should the motor fail to light for the critical liftoff from the moon. On liftoff, the backup engine was actually fired simultaneously with the main engine, but turned off if the main engine lit up. The LK had five chemical batteries, three on the descent stage, two on the ascent. Cabin pressure was oxygen/nitrogen at 560 mm.

The return-to-Earth profile was quite like Apollo. The LK would lift off from the lunar surface, using the landing frame as a launching pad, like the American LM. The LK would link up with the LOK in lunar orbit and the cosmonaut would transfer to the LOK, though this would be by an external spacewalk (indeed, it would be his third that day). The LK would be dropped, and then the LOK would fire its main engine for trans-Earth injection. There would be a quiet coast Earthward, followed by a high­speed skip reentry over the Indian Ocean and a soft landing in Kazakhstan.

The LOK and L-1 spacecraft were expected to return to Earth in the standard recovery zone in Kazakhstan. Here, the Russians had extensive experience of the Air Force recovering spacecraft using helicopters, trucks, amphibious vehicles, adapted troop carriers and other vehicles able to traverse the flat steppeland. This experience had been built up during the Korabl Sputnik missions and the Vostok series and consolidated as the military photoreconnaissance Zenit series began making regular missions. The real problem was if the L-1 or LOK came down outside Soviet territory, either by choice or if the skip return failed and a ballistic path was followed instead. The Indian Ocean was the most likely maritime landing point. Here, in a decree issued on 21st December 1966, the Soviet Navy was made responsible for Indian Ocean recoveries. For Indian Ocean recoveries, ten naval and maritime research ships were involved, supplemented by three ship-borne helicopters, spread out at 300 km points along the ocean.

The LK

Weight 5,500 kg

Height 5.2 m

Diameter ascent stage 3 m

Span, descent stage 4.5 m

Habitable volume 4m3

Hover time 1 min

Weight, ascent stage 2,250 kg

Weight, descent stage 2,250 kg

Crew 1

Length of legs 6.3 m

Were Soviet computers up to the job? The Apollo 11 American lunar landing nearly aborted when the lunar module’s computer overloaded and flashed alarms in the LM cabin. The Apollo computers, though the most sophisticated of their day, would be regarded as laughably primitive nowadays. They were bulky, crude and had limited memory, but they played an important part in getting Apollo to the moon and back again. The popular assumption is that Soviet computers during the moon race lagged far behind American ones. This does not seem to be the case now. The Soviet Union had a long tradition in advanced mathematics and developed, in the late 1950s, its own silicon valley, partly assisted by two exfiltrated American electrical engineers, com­munists and friends of the Rosenbergs, Alfred Sarant and Joel Barr [19]. Taking on fresh names, Philip Staros and Josef Berg, they built up Special Design Bureau 2 (Spetsealnoye Konstruktorskoye Buro 2, SKB 2) which developed microcomputers for the Soviet aviation industry, military and space programmes. This included the Argon computer used on Zond. During the 1960s, SKB 2 developed a series of small, lightweight, sophisticated computers, from laptops to navigational devices to big calculating computers. Just because Soviet computers followed a different develop­ment path from the West did not mean that they were inferior, for they were not. The ability of the USSR to achieve automated rendezvous and docking in space (1967) went unmatched in the West until 1998 when the Japanese satellites Hikoboshi and Orihime met in orbit.

INTO THE SEA OF RAINS

Luna 17’s mission was, at least for its first six days, apparently identical to that of Luna 16 and 15. A four-day coast out to the moon was followed by lunar orbit insertion circular at 85 km, 1 hr 56 min, 141°. On the 16th, the onboard motor lowered the orbit to an altitude of 19 km. Luna 17’s target was nearly a hemisphere away from that of Luna 16. The entire western face of the moon is dominated by a huge, dark ‘sea’ which is called the Ocean of Storms. In its northwest corner is a semi-circular basin, the Sea of Rains.

INTO THE SEA OF RAINS INTO THE SEA OF RAINS

After only two days in orbit, reflecting the bright sunlight of the setting sun, Luna 17 skimmed in low over the Jura Mountains. The retrorocket fired. Luna 17 came down as the radar checked the landing site. At 600 m, coming down at 255 m/sec, the final main engine burn was made. Down it came, as softly as a parachutist on a wind – free day. By the time it landed, Luna 17 weighed 1,836 kg. The long shadows of the structure stood out starkly toward the darkening east. For two hours, Luna 17 reported back its position. Russia coolly announced its fourth soft-landing on the moon. A return capsule would be fired back to Earth the next day – or so everyone

INTO THE SEA OF RAINS

Lunokhod descending to the moon

Not so. On the upper stage rested the first vehicle designed to explore another world. It had eight wheels, looking like pram wheels, which supported a shiny metallic car, covered by a kettle-style lid. Out of the front peered two goggle-like television eyes. Above them peeped the laser reflector and two aerials. It was an unlikely-looking contraption – on first impression more the outcome of a Jules Verne or H. G. Wells type of sketch rather than a tool of modern moon exploration. But the wheels were ideal for gripping the lunar surface and less prone to failure than caterpillars. The lid could be raised backward to the vertical and then flat behind, exposing solar cells to recharge the batteries in the Sun’s rays. The exposed top of the car was a radiator, discharging its electronic and solar-baked heat. There was genius in its simplicity.

The most dangerous part of the vehicle’s journey was probably getting off the platform and onto the lunar surface. Two ramps unfolded at each end, so it could travel down either way if one exit were blocked. Still sitting on the landing platform, ground control commanded the dust hoods to fall off the television eyes. A picture came back at once, showing the wheel rims, the ramp down to the flat bright surface and the silhouette of the landing ramps. There was nothing for it but to signal to Lunokhod to go into first gear and roll down the ramp and hope for the best.

So it was that at 6:47 a. m. on the morning of 17th November 1970, carrying the hammer and sickle, a red flag and a portrait of Lenin, the moon vehicle edged its way down the ramp and rumbled 20 m across the lunar surface. Its tracks were the first wheel marks made on another world. Its television cameras showed its every move and at one stage Lunokhod slewed around to film the descent stage which had brought it there. On day 2 it parked itself, not moving at all, lying there so that its lid could soak

INTO THE SEA OF RAINS

Lunokhod tracks across the moon

in solar energy for its batteries. On day 3 it travelled 90 m, 100 m the following day, overcoming a 10° hill. On the fifth day, with lunar night not long off, it closed its lid, settled down 197 m from Luna 17 and shut down its systems for the 14-day lunar night. At this stage, it had travelled a modest 200 m. A nuclear power source would supply enough heat to keep it going till lunar daybreak.

The Soviet – and Western – press took to Lunokhod with an affection normally reserved only for friendly robot television personalities. There was unrestrained ad­miration for the technical achievement involved, for it was a sophisticated automated exploring machine. The Times of London called it ‘a remarkable achievement’. ‘A major triumph,’ said The Scotsman. The Daily Mail, in a front-page editorial entitled ‘Progress on wheels’ gave Lunokhod’s designers an effusive message of congratulations. It was the main news story for several days.

The control centre for Lunokhod was, like much else in the venture, a scene straight from science fiction. It was located in Simferopol, Crimea, near the big receiving dishes. Five controllers sat in front of television consoles where lunar landscapes were projected on screens. The crew of five worked together like a crew operating a military tank. Signals were relayed to the drivers by the high-gain antenna which had to be locked on Earth continuously. The drivers operated Lunokhod with a control stick with four positions (forward, backward, stop, rotate), and they could make the rover go either of two speeds forward: 800m/hr or 2km/hr, or reverse. If the Lunokhod looked like crashing, either drivers or commanders could press a panic button to turn the electric engine off. Any one wheel could be disconnected individ­ually if it got stuck or there were a problem. Lunokhod was designed to cope with obstacles up to 40 cm high or 60 cm wide, but an automatic system would cut the engine out if it began to tilt. Average speed started at 2.3 m/hr but later increased to 4.8 m/hr. All the wheels ran at the same speed and they turned the rover like a tank by running the wheels faster on one side than the other, until the change of direction was achieved – skid-steering [5]. In reality, driving the Lunokhod proved to be quite a lot more difficult than the drivers expected. The drivers realized at once that the cameras were too low down – it was like being a human on all fours rather than upright. The television cameras were able to provide little contrast: the images were too white, and rocks and craters looked deceptively alike [6]. Driving the moonrover was strenuous and during the lunar days the teams alternated 9 hr shifts, catching up on sleep during the lunar nights.

So great was the excitement of the first Lunokhod that journalists, academicians and scientists flooded into mission control, apparently taking up a general invitation to do so by Mstislav Keldysh. Vistors were not supposed to crowd around the drivers, still less talk. But the situation got out of hand, especially when backseat drivers would exclaim: ‘He’s going to crash into that rock!’ or ‘Mind that crater!’ Between the natural stress, the heat coming out of the televisions and the backseat drivers, the drivers’ pulses crept up to 140 and the stress began to tell. Babakin had had enough. ‘Everyone out of here!’ he ordered and after that special passes were needed to visit the control room and then in a suitable state of humility [7].

Back on the moon, nighttime temperatures plunged to — 150°C and stayed at that level a full two weeks. Lunokhod, lid closed, glowing warmly from the heat of its own nuclear radio isotope, rested silently on the Sea of Rains. It was bathed in the ghostly blue light of Earth as the mother planet waxed and waned overhead. Even as it stood there, laser signals were flashed to Lunokhod from the French observatory in the Pic du Midi and from the Semeis Observatory in the Crimea. They struck the 14 cubes of the vehicle’s laser reflector and bounced back. As a result, scientists could measure the exact distance from the Earth to the moon to within 18 cm.

To the east of Lunokhod rose a ridge and the sharp rays of dawn crept slowly over its rugged rocks early on 9th December. Had the moonrover survived its two-week hibernation? This was an anxious moment and pulses began to race when the first command was sent to the Sea of Rains to open the lid. Nothing happened. They tried again and this time the rover responded. It raised its leaf-shaped lid and at once began to hum with life. Four panoramic cameras at once sent back striking vistas of the moonscape, full of long shadows as the Sun gradually rose in the sky. After a day recharging, Lunokhod set out once more. The Lunokhod got into big trouble straight

INTO THE SEA OF RAINS

Lunokhod route-planning conference

away. On 10th December, Lunokhod got stuck in a crater and no matter what the drivers did – go forward, go back – it remained stuck. Eventually, after nine exhaust­ing hours, the rover suddenly came free.

The drivers on Earth soon got into their stride and they had the moon car in second gear, swivelling around, reversing and traversing craters and slopes at will. One day it travelled 300 m, more than it had achieved in its first five days in November. Lunokhod took a south-southeast path, skirting around and between craters and parked in December in a crater at the southernmost end of the route, 1,400 m from the landing stage. In January, swivelling round to head back north, the panoramic camera eyes spotted in the distance a range of mountains – the far peaks of the Heraclides Promontory, part of the vast bay encircling the Sea of Rains.

For ground control it was just like being there. From the cosy warmth of their control post they could direct at will a machine a quarter of a million miles away. This prompted romantic notions in the minds of the Earthbound. Radio Moscow promised ‘more Lunokhods, faster and with a wider range.’ Boris Petrov spoke of mooncars

INTO THE SEA OF RAINS

Lunokhod tracks

that would collect samples and bring them to craft like Luna 16 for transporting home. Others would instal packages on the moon and carry telescopes to the farside where there was radio peace, free from Earthside interference. Other probes would reach the lunar poles.

It turned out that the drivers had been well selected for their mission. The drivers faced several challenges. First, the 20 sec frame transmissions were too slow. Although driving the lunar rover might seem simple enough to a modern generation reared on video games, in reality the crew had to memorize features some distance ahead. The 20 sec time gap between frames meant that Lunokhod could reach a feature – stone, rock, crater, obstacle – a full third of a minute before the crew saw visually that it had arrived. Second, the cameras were set in an awkward place: too low to see far ahead, yet set toward the horizon in such a way as to create a dead zone immediately in front of the rover that the drivers could not see. Third, the light contrasts of the lunar surface made driving difficult, the drivers having to cope with extremes of shadows and glare. Rather than risk driving across shadowless moonscapes, operations were normally halted for two days at lunar high noon. From time to time, Lunokhod would

INTO THE SEA OF RAINS

Lunokhod returns to landing stage

stop to take panoramic pictures. For the drivers, these were good opportunities to orientate the rover and plan the next stage of the journey.

L-l ZOND 5

Autumn was well in the air and the nighttime temperatures were cool once more when at midnight on 15th September 1968, Zond 5 rose off the pad at Baikonour and its Proton launch vehicle silhouetted the gantries, masts and assembly buildings for miles around. It all went effortlessly well, all the more remarkable after the frustrating 18 months which had passed since Cosmos 154 had triggered off so many frustrations. Sixty-seven minutes later, Zond 5 was moonbound, right on course. Its cabin con­tained two small turtles, fruit flies, worms and 237 fly eggs. The spacecraft weighed 5,500 kg. The plan was to recover Zond on Soviet territory after a skip trajectory, but failing that in the Indian Ocean on a ballistic return. Ten ships, equipped with three helicopters, had been sent as a recovery task force and spread out at 300 km intervals. Cameras were carried to take pictures of the close approach to the moon. Designed by Boris Rodionov of the Moscow State Institute for Geodesy and Cartography, they appear to have been developed from mapping cameras rather than from the earlier lunar missions. The standard camera for the Zond missions was a 400 mm camera taking 13 by 18 cm frames. Publicly, the official announcement said even less about the mission than usual.

Chief designer Vasili Mishin flew from Baikonour to follow the mission at the control centre in Yevpatoria. Everything was going well and the control team partied into the night. Then news came through that the stellar orientation had failed. Alexei Leonov recalled how Vasili Mishin, despite having more than enjoyed the party, analysed the problem correctly right away and had it fixed. He had good intuition, noted Leonov.

On 17th September at 6: 11 a. m. Moscow time, after one failed attempt, Zond 5 successfully corrected its course at a distance from Earth of 325,000 km. At Jodrell Bank Observatory in Manchester, Sir Bernard Lovell quickly pointed his radio dish to track the enigmatic Zond 5. He picked up strong signals at once, receiving 40 min bursts on 922.76 MHz. On 19th September he was able to reveal that the spacecraft had been around the moon at a distance of about 1,950 km and was now on its way back. This information was based on the signals he had received. But nobody really knew. The Soviet Ministry of Foreign Affairs categorically denied that Zond 5 had been anywhere near the moon.

If the mission planners had been as inept as the Soviet news service, the flight would have failed at this stage. As it was, Zond 5 had seen the Earth disappear to the size of a small blue ball in the distance. Any cosmonaut then on board would have been treated to the fantastic spectacle of the moon’s craters, deserts and rugged highlands sweep below him in stark profusion. Zond soared around the moon’s farside and then, nearing its eastern limb, a nearly full Earth rose gently over the horizon, a welcoming beacon to guide the three-day flight home. Would a cosmonaut soon see and feel this breathtaking vista?

Early 20th September. A belated Russian admission that Zond 5 had indeed been ‘in the vicinity of the moon’ (as if any spacecraft happens to find itself ‘in the vicinity’ of the moon) was eclipsed by new, even more startling news from Jodrell Bank. A human voice had been picked up from Zond 5! Was this a secret breakthrough? Had a

L-l ZOND 5

Zond 5

man been aboard all along and would the Russians then announce an historic first? Not likely, said Sir Bernard Lovell. It was a tape-recorded voice, designed to test voice transmissions across deep space (one of the voices was Valeri Bykovsky’s). He expected the next flight would have a cosmonaut aboard. Some 143,000 km out from Earth, Zond 5 corrected its course to adjust the entry angle. Jodrell Bank continued to track the probe till it was 80,000 km from the Earth and picking up speed rapidly. Zond 5 took its last pictures of Earth as it filled the porthole.

Zond 5 was indeed returning to the Earth. One of the reasons for Moscow’s reticence was that the mission was not going well. The astro-navigation sensor had broken down, this time for good and then the gyro-platform had failed, making it impossible to restart the main engine. As a result, the two small orientation engines had to be used to set up the craft for reentry. Chances of recovery were considered slim and the gyro failure meant that a skip reentry would now be impossible. Zond 5 would now reenter steeply, ballistically.

At 6: 53 p. m. Moscow time, 21st September, the L-1 cabin reached the limb of the Earth’s atmosphere over springtime Antarctica, met its 10 km by 13 km reentry frame dead on, slammed into the atmosphere at 11 km/sec and burned red hot to a temperature of 13,000°C. Gravity forces built up to 16 G. After 3 min, the ordeal was over. A double sonic boom, audible over the nighttime Indian Ocean, signified survival. Still glowing, parachutes lowered the simmering Zond 5 into the Indian Ocean at 7: 08 p. m. Beacons popped out to mark the location of the bobbing capsule, some 105 km distant from the nearest tracking ship. The naval vessel Borovichy moved in the next morning, took Zond out of the water and hoisted it aboard: in no time it was transferred to a cargo ship – the Vasili Golovin, en route to Bombay – where it was brought to a large Antonov air transport and flown back to the USSR. The capsule was intact, the two turtles had survived, some fly eggs had hatched and there were pictures of the Earth from deep space.

In one sweet week, all the reverses of the past 18 months had been wiped out. The moon could be Terra Sovietica. The first glimpse out of the porthole, the historic descriptions, the joy of rounding the corner of the moon – these could yet be Soviet successes. Zond 5 had become the first spaceship to fly to the moon and return successfully to the Earth. It was a real achievement.

All NASA could do now was cross its fingers and hope against hope that the Russians would not somehow do a manned mission first. They now knew they could. Before long the Russians released information which confirmed NASA’s worst fears. They announced that Zond was identical to Soyuz, but without the orbital compart­ment. It had air for one man for six days. It carried an escape tower. The Soviet Encyclopaedia of Spaceflight, 1968 rubbed it in: ‘Zond flights are launched for testing and development of an automatic version of a manned lunar spaceship,’ it said.

THE SOVIET/RUSSIAN LUNAR PROGRAMME AFTER 1976

Some time before the cancellation of Luna 25, references to future Soviet lunar exploration had already dried up in the Soviet press. In July 1978 it was briefly reported that a lunar geochemical explorer was under consideration and due to fly by 1983, but nothing more was heard of this project. At around that time, NASA was trying to persuade Congress to fund a lunar geochemical polar orbit – with equal lack of result.

The moon was now relatively well known and Keldysh made the argument to the political leadership that the USSR should no longer try to directly compete with the United States. Both he and the director of the Institute of Space Research (IKI in Russian), Roald Sagdeev, argued that the USSR should concentrate on what it was good at, had proven expertise and did not compete directly with the Americans. This pointed the Soviet Union in only one direction: toward Venus. Here, the Soviet Union had parachuted probes through Venus’s atmosphere in 1967 and 1969 (Venera 4, 5-6), soft-landed simple probes on its surface in 1970 and 1972 (Venera 7, 8) and put down sophisticated landers in double missions in 1975, 1978 and 1985 (Venera 9-10, 11-12,
13-14, Vega 1-2). Venera 13 and 14 drilled Venusian soil and analyzed it in an onboard laboratory. Balloons were dropped into the Venusian atmosphere (part of the Vega project). Orbiters first circled the planet in 1975 (Venera 9, 10) and then in 1983 radar-mapped its surface (Venera 15-16). By the end of the Vega programme in 1986, Venus’s surface, atmosphere and circumplanetary space had been well characterized.

Mars took second place in the Soviet programme for interplanetary exploration. The Russian Mars 3 probe became the first spacecraft to soft-land on the Red Planet and sent a picture from its surface in December 1971. The Soviet Union obtained a full profile of the atmosphere right down to the surface during the descent of Mars 6 into the Mare Erythraeum in March 1974. After a gap of many years, the USSR went on to organize an imaginative mission to Mars’s little moon, Phobos, in 1988-9 (the first probe failed, the second achieved limited success). The Americans began a wave of missions to Mars in the 1990s, each one revealing more and more of what an interesting planet it was.

In the light of the genuine progress made in the successful exploration of Venus and the sustained interest in Mars, it is little wonder that the further scientific exploration of the moon became a low priority. Eventually, though, coinciding with a reforming political leadership in the Soviet Union, some plans were advanced. In 1985, the idea of a lunar polar orbiter was resurrected. In 1987, the Institute for Space Research (IKI) in Moscow gave this mission a target gate of 1993, with a lunar farside sample recovery in 1996 and an unmanned laboratory on the moon, with rovers, in 2000. In its last plan for space development published in 1989 (The USSR in outer space – the year 2005), the Soviet Union proposed a lunar polar geophysical orbiter, but few details were given and only a sketchy illustration was published, suggesting it would use the Phobos spacecraft design. At one stage, the project acquired the name Luna 92, indicating a 1992 launch date, but it never got beyond the preliminary design stage and the money originally set aside for it was used for the Mars 96 planetary mission instead.

THE LUNAR PHOTOGRAPHY MISSIONS

Now that lunar orbit had been achieved ahead of the Americans, the programme could now return to the original, planned Ye-7 lunar-orbiting photography mission. The Ye-7 was renamed the Ye-6LF at this stage. It used the same Ye-6 bus. Instead of the landing cabin, there was a non-detachable cone and box-shaped camera system. Luna 11 carried the same camera system as that flown on Zond 3, which in turn was designed for the 3MV series of Mars and Venus probes over 1964-5. The photographs were expected to cover 25 km2 each, with a resolution of 15 m to 20 m. Once taken, the photographs would be developed and dried. They would then be scanned by a television system on board. Besides the camera system, seven scientific instruments were carried, the same as the Ye-6S, Luna 10. The whole spacecraft weighed around

I, 620 kg.

The first Ye-6LF, with a full photographic suite on board, was eventually launched on 24th August, after the first American lunar orbiter had arrived. Called Luna 11, it left Earth on 24th August and entered moon orbit of 159 by 1,193 km, 27°, 2 hr 58 min. After burning propellant, the mass entering lunar orbit was in the order of 1,136 kg. The Russians had learned their lesson from the Luna 9 episode over the photographs. The Russians faced a choice of sending down pictures only when Yevpatoria was in line of sight, which would take many weeks, or to send them down when stations farther afield, including their own, could pick them up. They decided on the latter course. In a crafty ruse, the decision was taken that transmission would switch rapidly between the two downlink frequencies, too quickly for Jodrell Bank to reconfigure its systems. Moreover, all the photographs were to be taken in the first 24 hours of the mission and transmitted straight away, before this cat-and-mouse technique could be realized or countered.

The Russians reported completion of the mission on 1st October after 38 days, 277 revolutions and 137 communications sessions – but the long-awaited pictures were never published, nor was much else said. Only after glasnost did the Russians admit that the mission had failed in its primary purpose and that the pictures had never reached Earth in the first place. Although the cameras had worked, a problem with the thruster systems meant that the spacecraft had not been pointing at the moon at all, but taking pictures of blank space! This was due in turn to a foreign object getting stuck in one of the thrusters, making orientation impossible. Luna 11 also carried instruments to measure gamma rays, X-rays, meteorite streams and hard cor­puscular radiation. Specifically, it was instrumented to confirm Luna 10’s detection of mascons. The scientific outcomes are not known and few lunar results were attributed to Luna 11. Russian accounts of the scientific results of the 1966 orbiting missions give details of outcomes from Luna 10 and 12, but not 11 [10]. Luna 11 carried, as did its successor, gears and bearings designed to be used on subsequent lunar rovers, to test how they would work in a vacuum.

Luna 12 (22nd October) passed the moon at 1,290 km at a speed of 2,085 m/sec when its retrorocket fired for 28 sec to cut its velocity to 1,148 m/sec to place it into an orbit of 100 by 1,737 km, 3 hr 25 min, in a much narrower equatorial orbit than Luna

II, only 15°. This time, lunar photography was the stated mission objective and

THE LUNAR PHOTOGRAPHY MISSIONS

Luna 11, 12 design

presumably this was accomplished on the first day during the low points of the orbital passes. Thrusters were used extensively to point Luna 12 toward landing sites and on the second day the spacecraft was put into a slow roll so as to accomplish the rest of its mission.

The whole mission lasted three months and ended on 19th January 1967 after 85 days, 602 orbits and 302 communications sessions. The imaging, scanner and relay system had a resolution of between 15 m and 20 m and could be transmitted at either 67 lines/frame for 125 sec (quick look) or at 1,100 lines a frame for 34 min (high resolution). The target areas were the Sea of Rains, Ocean of Storms and craters Ariastarcus and Alphonsus: a Soviet photograph released late in 1966 showed cosmonauts Yuri Gagarin, Alexei Leonov, Vladimir Komarov and Yevgeni Khrunov pouring excitedly over its pictures.

The Russians gave only a short account of the Luna 12 mission, the principal one being Luna 12 transmits, published in Pravda on 6th November 1966 and they released only a small number of images from Luna 12, much inferior in quality to the American

THE LUNAR PHOTOGRAPHY MISSIONS

Luna 12 images

lunar orbiters and doing less than justice to the 15 m resolution of the cameras [11]. There are some reports that the photographs were so poor that the Russians ended up resorting to assembling the publicly available American Ranger and Lunar Orbiter archive to plan their moon landings; but this could be a traditional Western under­estimate of Soviet photographic capabilities. There is no suggestion that anything went wrong, so the pictures must have been at least up to the standards of Zond 3. Because they were taken at much closer range, they were probably much better. Either way, it is more than likely that there are still some Luna 12 pictures deep in some Moscow archive. In addition to cameras, Luna 12 carried a gamma ray spectrometer, magnetometer, infrared radiometer and micrometeorite detector. Assessments were made of the reflectivity of the lunar surface to infer its density (1,400 kg/m3).

Presumably, the Luna 12 pictures would have been decisive in determining where the Russians would land on the moon. The American lunar orbiters enabled the Americans to narrow down the choice of the first landing to five prospective sites, all near the equator (likewise, Luna 12 flew over the equatorial belt, between 15°N and 15°S, in a much narrower band than Luna 11, which operated between 27°N and 27°S). A team in the Vernadsky Institute, led by Alexander Bazilsvsky (b. 1937), worked on site selection for the manned landing from 1968 and also for soil sample and rover missions. Eventually, the Russians selected three smooth areas for the first manned landing on the moon: [2]

THE LUNAR PHOTOGRAPHY MISSIONS

Евдокм»*ов’

[Ковалеве*»

[Разумов

 

(Блажко!

 

ОЙНТИНГІ

 

Лебединский

 

ІІВИЛЄп]

 

THE LUNAR PHOTOGRAPHY MISSIONS

THE LUNAR PHOTOGRAPHY MISSIONS

КлеАмеио»

Іебмшев

Подпись: Максутов!наді vm

Ye-6LF (originally Ye-7)

Height

Base

Подпись: 2.7 m 1.5m 1,665 kg 100 x 1,700 km From 15 to 27° 178 to 205 min Weight (payload) Orbiting altitude Angle to equator Orbital period

Подпись: Sites for manned lunar landing

Ye-6 series: instruments specified1

Magnetometer.

Gamma ray spectrometer.

Gas discharge counters.

Electrode ion traps.

Meteoroid particle detector. Infrared radiometer.

Подпись: 1 Cannot be confirmed that all were flown on each mission.

Low-energy X-ray photon counter. Cameras (Ye-6LF).

THE LUNAR PHOTOGRAPHY MISSIONS

Luna 10 and mother ship

 

Summary of lunar orbiters Ye-6S and Ye-6LF

Подпись: Failure (Cosmos 111) Luna 10 Luna 11 Luna 121 Mar 1966 31 Mar 1966 24 Aug 1966 22 Oct 1966