The full L3 craft leaves Earth orbit. The lunar orbiter is the green portion to the right, while the lander is covered by a fairing to the left of the gold-coloured portion until reaching the Moon. Image by Eberhard Marx and used under a Creative Commons Attribution 3.0 Unported license. Click for a larger view.
What it was: The Big One. This was the Soviet Union’s main response to the US’ Apollo program, running from Sergei Korolev and OKB-1 formally wresting the Moon landing from Vladimir Chelomei in 1965 until after the landing of Apollo 11. It would have sent two men to the Moon aboard a customized Soyuz, one of whom would then enter the purpose-built LK lunar lander and descend to the surface. Apart from the smaller crew, it was similar in many ways to the Apollo approach.
Details: For a period of about a year beginning in August 1964 the composite Soyuz craft originally intended for the Soviet Moon mission, the 7K/9K/11K, languished as responsibility for landing a cosmonaut on the Moon was given instead to Vladimir Chelomei. Recognizing that his original conception was not moving forward, in February 1965 Sergei Korolev re-oriented his approach to work solely on the 7K and Earth-orbital docking maneuvers, a variant called the 7K-OK. This version of the Soyuz was approved in February 1965.
At the same time, Korolev had no intention of giving up the Moon mission. The 7K/9K/11K would have required multiple launches to build and fuel in Earth orbit, so at least partially for the purpose of making the mission simpler and cheaper OKB-1 switched proposals to a Lunar Orbit Rendezvous profile that would need just one N1 launch. Then Korolev went back to work on the Soviet leadership; by February 1965 he’d convinced them to at least let him look at the manned mission, and by October he had managed to kill most of Chelomei’s programs. The other designer was left with only the UR-500K booster (which would become the Proton) for the manned circumlunar flight, but with a Soyuz derivative (the Zond) as the capsule. For the next several years the manned Moon landing would be in the hands of Korolev and his successors as they worked to develop the L3—a Soyuz 7K-OK variant called the LOK (Lunniy Orbitalny Korabl or “lunar orbital ship”)and a lunar lander, the LK (Lunniy Korabl, or “lunar ship”)—to sit on top of the N1 rocket that would be developed at the same time.
The work was primarily that of his successors, as Korolev died in January of 1966, his lieutenant Vasili Mishin took over OKB-1, and the bureau was re-organized as TsKBEM. The N1-L3 project became the deceased Chief Designer’s legacy to the Soviet space program.
What they came up with was a remarkable arrangement. Due to the lower payload capacity of the N1 (95 tonnes as compared to 120 for the Saturn V) and the tendency for 60s-era Soviet hardware to be on the heavy side anyway all else being equal, the LOK and the LK had to be smaller than the equivalent Apollo craft—9850 kilograms for the former and 5500 kilograms for the latter. By contrast the Apollo CSM by itself massed 30,322 kilograms even before getting to the LM. Accordingly the mission would carry only two cosmonauts, one of whom would go down to the surface. Three teams of two were selected as the best for this mission: Alexei Leonov and Oleg Makarov were considered the likeliest, with Leonov being the one to walk on the Moon. The other two teams were Valeri Bykovski and Nikolai Rukavishnikov, and Pavel Popovich and Vitaly Sevastianov—the former in each pair being the Moon walker.
The surprisingly large difference in weight between Apollo and L3 was necessary because not only were the three stages of the N1 necessary the L3 into orbit, the craft that left Earth had another two (compare Apollo, which got sent on its way by the third stage of the Saturn V, which was only partially spent by the climb to orbit). Having been lifted to LEO, after one orbit the first stage of the L3 would perform the translunar injection burn and start the cosmonauts on their long journey to the Moon; having performed the burn, it would be jettisoned and the remainder of the L3 would carry on.
Upon arriving at the Moon, the second stage was the one that did the most work. It would first get the L3 into a circular parking orbit, and then when the descent began it would fire to get the whole craft down to a perilune of only 16 kilometers.
This leads to another difference between Apollo and the L3. Shortly after leaving Earth orbit, the Apollo stack would reconfigure itself by having the CSM move away from the rest of the craft a short distance, rotate 180 degrees, and then return to dock with the LM nose-first. This opened up an internal transfer tunnel between the two before the trip to the Moon. The L3, by contrast, stayed in one piece during its journey. Once the ship was in its low-flying lunar orbit, the cosmonaut who would be making the trip down to the surface would leave his fellow traveller in the LOK’s descent module, put on his Kretchet-94 spacesuit in the orbital module, seal off the hatch between the two, and then exit the Soyuz out the main hatch. He would then spacewalk to the LK along the side of his ship using a variety of handholds including a pole connecting it to the LOK.
A comparison of the LK lander with the Apollo LM. For obvious reasons, the LK could carry only one cosmonaut. Public domain image via Wikimedia Commons. Click for a larger view.
Once aboard the LK, the cosmonaut would disconnect the lander and the second rocket stage from the rest of the craft and fire the latter to begin the final descent. Now burning for the third time, the rocket would actually get him down to 1500 meters before being jettisoned to crash on the surface nearby; at this point the LK’s engine would kick in. From that moment the pilot had one minute to find a landing spot—half the time an Apollo LM had. It’s worth pointing out that, unlike for the American astronauts, the Soviet pilot had the option of going longer if he needed to: the LK had only one rocket motor, and so his final descent engine was actually his ascent engine too. If he wanted to, he could eat into the fuel he needed to get back into lunar orbit to extend his landing time. Though obviously it wasn’t a good idea to keep this up for long, it made the LK a little more flexible and arguably safer than the American LM. The US’ lander had two motors, one for landing and one for return, and if the landing engine ran out of fuel while still in the air there was a height below which it wasn’t possible to start up the ascent engine in time to prevent a crash (this largely explains why Mission Control had “a bunch of guys about to turn blue” as Neil Armstrong coasted a few meters above the surface hunting for a landing spot in Eagle).
How long the LK would stay on the Moon was never determined, but it couldn’t have been too long as it’s known that there would have been no sleep period for our lone cosmonaut. The EVA on the surface would have been about four hours, during which he would obtain samples and set up the mission’s weight-limited experiment suite. As well as two seismometers, this would have included a mini-rover attached to the LK’s landing gear by a cable for power and telemetry—after the explorer left to go home, Soviet scientists back on Earth could drive it around and continue exploring the site by remote control.
Once the EVA was completed, the cosmonaut would reboard the lander and blast off for the LOK in orbit, leaving behind the LK’s landing legs as dead weight. The LOK’s pilot would home in on him and dock by means of a near-foolproof arrangement that simply required a spike-like probe on top of the LOK to punch out any one of 108 hexagonal cells contained in a large “shade” on top of the lander for solid contact. Having joined back up the moonwalker would then spacewalk a second time, back to the LOK.
From then on the L3’s mission profile was very similar to the Apollo landings. The LK would be jettisoned, and the LOK’s engine would perform a trans-Earth injection burn to get them home. Upon arrival at Earth the Soyuz would make the usual three-part separation of its type, the propulsion and orbital modules being allowed to burn up while the re-entry module made a more controlled descent. If possible, it would skip off the atmosphere to land somewhere in the Soviet Union (preferably the Kazakh SSR), but if not it would land in the Indian Ocean to be picked up by Soviet naval units strung all across its basin.
Before sending out the mission, the LOK and LK were tested a number of times. The LK proved to be quite successful: on November 24, 1970 one was launched into Earth orbit, left for three days to simulate the journey in vacuum to the Moon, and then run through the various burns it would need to land, wait while its hypothetical cosmonaut walked on the surface, and then take off again. It did so, and then remained in orbit until re-entering uncontrollably over Australia in 1983. Interestingly, the USSR felt it diplomatically necessary to explain to the Australian government that it was just a lunar lander and not a nuclear-powered satellite like Cosmos 954, which had come down over Canada in 1978 strewing radioactive waste in its wake. This was the first crack in the Soviet post-Apollo 11 cover-up and denial of their manned Moon landing program.
Three more LKs would be launched and tested in orbit by August 1971 and so it was ready to go, but circumstances make the LOK’s readiness more of a mystery.
What happened to make it fail: The L3 was part of the larger N1-L3 program and so the decision to go for a single-launch, LOR mission was fateful. Many of the N1’s problems came about because now it needed to be upgraded from its initial design of 75 tonnes to low Earth orbit. This wasn’t enough to lift the LOK, the LK, and the craft’s two fuelled rocket stages, and so every method possible was used to squeeze another 20 tonnes out of the rocket, much to its detriment. A dummy 7K-LOK made it into orbit on top of a Proton on December 2, 1970, but two other attempts (one dummy and one real one) were aboard the final two tries at launching an N1, and so failed when those rockets exploded—though both times the LOK was recovered by their emergency escape system.
Even beyond the N1’s troubles there were a number of places where the Soviet Union made time-wasting mistakes as compared to Apollo. For one, they were very late in starting: Korolev had been pushing for a manned mission to the Moon since Kennedy made his challenge, yet formal approval for the project didn’t come until August 1964.
Even then the Soviet Moon program was split between two designers. In August 1964 it was Vladimir Chelomei who was given the assignment because he’d had the political savvy to give Khrushchev’s son an engineering job. After Khrushchev fell from power it took another year for Korolev to get the Moon program assigned to him instead. Essentially real work on the L3 couldn’t begin until the end of October 1965.
Chelomei’s continuing presence in the lunar flyby program was a problem too. Unlike Apollo where the same craft was used for both flybys and landing missions (the CSM), using a Proton for the flyby forced the Russians to develop two related-but-different craft, the 7K-LOK and the much stripped-down Zond. This duplication of effort wasted time and resources.
Korolev’s death and replacement with Vasili Mishin also hurt. While his contemporaries generally say that he was comparable to his predecessor as an engineer, they also say that he didn’t have Korolev’s people skills—including the political skills to impose his ideas on 1960’s-era Soviet leadership. Some even say that they believe that, given more time, Korolev would have eventually managed to cut Chelomei out of the picture entirely and ended up with a proper, single effort to get the USSR to the Moon.
This led to the final problem. As the other approach to saving weight was downgrading the spacecraft, even to the casual eye it was an inferior craft to the Apollo CSM/LM, not only in crew size but in the relatively primitive way the LK’s pilot had to spacewalk from the LOK just to get to his craft. The L3 would have been a triumph if it had got the Soviet Union to the Moon prior to Apollo 11, but once Neil Armstrong put foot to the Sea of Tranquility it was obviously second best. The Soviet Union’s leadership lost interest in the L3 mission for fear that it would look like a weak response to the American triumph. It sputtered along for a while (note the various post-May 1969 dates mentioned for the tests above), but Mishin’s TsKBEM was instead directed to work on the more ambitious three-man L3-M instead and told that only that would be acceptable for the actual mission.
What was necessary for it to succeed: Essentially they needed to pick something and stick with it, and continue on even if they “lost” to the US.
The infighting between Korolev and Chelomei left the Soviet manned space program in disarray, and even when it was supposedly settled it was with a solution that satisfied no-one. Korolev needed that extra year that was wasted in 1964-65, while simply letting Chelomei get on with it might have produced a Moon landing too—he was slow but talented, so while he may not have put a Russian on the Moon before about 1975, he would have done it.
This all assumes that the Soviet leadership put any value on the Moon program beyond its propaganda value, or could be convinced that there were still accomplishments to trumpet after the Americans beat them to the Moon. This is very difficult to see, as the leadership was right—given the amount of money they were going to have to spend, the returns of a manned Moon landing were very weak without some prestige to squeeze out of it too. The Soviet Union needed to get there first or else there was no point in going.
This is actually the real problem, since it’s unlikely that the USSR was going to get to the Moon before the US with the four-year head start they gave their competitors. The Soviet Union’s successes in space depended on getting the jump on the US, as they certainly weren’t going to beat them in resources or technical savvy. Ultimately once the Americans got going on the project, control of the race was out of the Soviet Union’s hands—they needed the Apollo team to make mistakes that let them catch up, and as we know the US made only one serious mis-step, with Apollo 1. It wasn’t enough.