N1-L3: The Soviet Moon Landing: Two Launches Using the Ye-8-2 Robot Beacon and LK-R backup lander
In a situation analogous to the L1, Korolev had sold the Soviet leadership on supporting the N1-L3 program on the basis of a single launch of the N1 booster to achieve a Soviet man on the moon. However two-launch scenarios were considered from nearly the beginning. This was not because, as Soviet critics alleged, that it was impossible to get the mass of the L3 lunar payload down to the available payload of the N1 (although there are pages showing every kilogram being squeezed out of the L3). It was rather for safety and guidance concerns.
The two-launch N1 scenario did not involve two lunar expeditions or separate launch of the 7K-LOK lunar orbiter and LK lunar lander. Instead, the first launch would be of a Babakin Luna Ye-8-2 robot lunar landar and an unmanned backup version of the LK lunar lander, the LKR. In the final version of this scheme, the Ye-8 would land on the moon, check out the landing site, and was equipped with a the beacon of the 'Liga' system, which would allow an LK to automatically home in for a precision landing nearby. (The identification of the Ye-8 beacon version as Ye-8-2 is new; previously only the Ye-8-5 designation for the later soil return version was known).
The second N1 would launch the L3 lunar expedition, with a crew of two aboard the LOK lunar orbiter and the primary LK. The single cosmonaut that would descend to the surface would spacewalk from the LOK lunar orbit to the LK, and then land on the moon using the Liga system. In the event his LK was faulty, and could not depart from the lunar surface, the LKR delivered in the first launch would land automatically using the Liga system, providing a rescue spacecraft for the cosmonaut to return to lunar orbit and dock with the waiting manned LOK.
This scenario was discussed as early as 2 December 1966 (1-235) in an interdepartmental technical review with MV Keldysh. At this point the Ye-8 would be delivered to the moon by a UR-500K launch vehicle. The basic constraint was the 5300 kg payload capability of the Block D to translunar injection. This meant tradeoffs in the accuracy of the Ye-8's initial landing versus its lifetime on the surface waiting for arrival of the LK. It was agreed that a working group would meet the next day to develop final specifications for the Ye-8 and a more detailed outline of the N1-L3 expedition plan using Ye-8. (start-up sequence, the time, the connections between LK, LOK and Ye-8, the means for determining the location). KD Bushuyev was to study the backup LK concept.
As an alternative, the possibility was raised in April 1967 of the Ye-8 being equipped with a life support system to allow the cosmonaut to remain on the moon until a rescue expedition could be launched with an LKR. But Ye-8 chief designer Babakin said at that time that this was not feasible (2-60; 2-62). However as if 29 August 1968 (2-149) it was still being pursued, with Mishin complaining the detailed specifications for the Ye-8 life support system with interface documents for connections to the cosmonaut's space suit had not yet been issued.
On 14 October 1967 (2-84) detailed issues of communicating simultaneously at lunar distances with the Ye-8, LK, and LOK from both the Crimea and Cuban tracking stations were being worked out. At the the Lunar Soviet of 25 November 1967 (2-90) the same issues were considered in relation to Soviet tracking ships.
By 1 February 1968 (2-119), in preparation for a Soviet of Chief Designers four days later, detailed consideration of many issues was underway. These included changes to the baseline LK orbit and ascent trajectories to allow rendezvous of an LKR with the waiting LOK even after a delay of more than six orbits in departure; and changes to the landing profile to prevent shrapnel from jettison of the LKR's Block D lunar crasher stage impacting the waiting cosmonaut's LK. 250 liters of increased propellant would be required in the LKR for a higher altitude Block D jettison; or the Block D could continue firing and make a maneuver after separation to assure it would impact well away from the active landing site.
The plan was disclosed to the other Chief Designers on 5 February (2-120). Chertok compared the "Kontakt" and "Liga" systems, and noted that the "Liga" elements in the control loop control system simplified LK landing. MS Ryazanskiy noted that this contradicted a decision two years ago to have the LK make an autonomous landing on the moon (LK homing on and landing near a beacon was postponed at that time). But AS Mnatsakanian supported the approach, saying it was necessary to speed up the development of the "Liga", which provided a precision landing on the moon within 50 to 100 m of the target.
On 7 February 1968 (2-120), at the expert commission on the UR-500K-L1 (Tyulin, Stroganov, Keldysh, Kashtanov and others), Bushuyev provided the status of development of the LK-R. A note on 17 June 1968 (2-139) indicates continued discussion within OKB-1 with VK Bezverby and KD Bushuyev on homing (the word actually used was berthing) the LK and LK-R on the Ye-8 (precision landing, coordination of interfaces). Finally the issue was taken to the top, at a meeting with DF Ustinov, head of the Military Industrial Commission, on 23 August 1968, where the N1-L3 expedition using the Ye-8 was pitched by Babakin (2-149).
But the triumph of the American Apollo 8 orbiting the moon in December 1968 made it clear that the Soviets would not be first to the moon. At a meeting with SA Afanasyev on 10 January 1969, alternatives were discussed. Afanasyev considered that one near-term solution would be a 2 launch scheme => 2 crew:0 crew). Ryazanskiy mentions the Ye8-4 (otherwise not identifed - perhaps an early version of the Ye-8-5), and states, "It is necessary to rethink the N1-L3 program. The scheme cannot be single launch. (LK-R + Ye8-2); 2 launch scheme with docking in lunar orbit."
On 24 January 1969 Mishin noted (2-158) "T1K, T2K, L1E essential"; and again reviewed the scheme for a lunar expedition of LK + LK-R + Ye-8. This was followed the next day in a meeting with his guidance expert, NA Pilyugin, "It is necessary to consider the possibility of 2 launch schemes: with Ye-8 and without Ye-8 OV (Examine all possibilities to improve the accuracy of the landing)."
The first N1 missions would rehearse the two-launch scenario, with the Ye-8 being launched by a UR-500K and an L3S standing in for the LOK (no LK being available yet). Kamanin had already noted in his diary on 3 February: "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."
In reality the UR-500K booster failed again on 19 February and the Ye-8 crashed 15 km from the launch pad rather than landing on the moon.
Despite part of the rehearsal for the two-launch scenario being voided, the first N-1 was launched on 21 February, and failed after 69 seconds of flight.
On March 9, the Americans launched Apollo 9, and tested all of the booster and spacecraft for the manned lunar landing successfully in low earth orbit. Barring a disaster, the Americans would clearly win the moon race by summer, and the N1-L3 would have very little propaganda value any more.
With this in mind, by 16 April 1969 it appears that the LKR is being considered as a possibility to extend the duration and scientific value of a two-launch lunar landing (2-176) with the note "KD Bushuyev - On the development of instrumentation for research on the moon aboard the LK-R." This is followed by a meeting on 3 June with senior government managers (2-202): "Meeting in TsKBEM with LV Smirnov, MV Keldysh. et al. Issues that require acceleration: ...3. Development of LK-R in an automatic version with a maximum use of opportunities to expand research."
On May 26, Apollo 10 returned from the moon, the crew having descended to within 15 km of the surface without landing. The way was now set for Apollo 11 to land in July.
A scheme had already been formulated in January to upstage the Americans. The Ye-8-5, a version of the Ye-8 designed to drill a small sample of lunar soil and return it to earth would be accelerated (2-187). This could be launched in coordination with the L3S. Although not a manned lunar landing, it would provide a Soviet crew in orbit around the moon, and return of lunar soil to earth, nearly matching the Apollo mission. The last chance to upstage the Americans was a combined launch of the N1-L3S and Ye-8-5 before Apollo 11 in July.
But again failures wrecked the scheme. The first Ye-8-5 was lost when the Block D failed to put it on a translunar trajectory on 14 June 1969. The launch of the N1-L3S on 3 July resulted in an enormous explosion on the pad. A final launch of the Ye-8-5 (as Luna 15) succeeded in getting to the moon, but crashed into the surface. On 21 July Chertok recalled:
We watched the Apollo 11 flight on the television at TsNIImash. After the happy conclusion of the lunar expedition, Tyulin proposed stopping by the director's office. There, over a glass of cognac, he said: "This is all Chertok's fault. In 1945 he came up with a scheme to snatch von Braun from the Americans and didn't manage to pull it off." Chertok replied bitterly: "And it s a very good thing that Vasya Kharchev and I failed in that undertaking. Von Braun would have sat for some time in our country uselessly on an island, and then he would have been sent to the GDR, where as a former Nazi he wouldn't have been cleared to work anywhere. And so with the help of the Americans, he fulfilled not only his own dream, but also that of all mankind."The two-launch scenario with the LKR was still the baseline for at least a year. On 16 February 1970 Mishin notes (2-301): "9. Refine Lunar Expedition using LK, LK-R and Ye-8." This is the last mention; by 1971 a new five-year plan had been approve d. Under this plan the N1-L3 was dropped and OKB-1 was pursuing the N1 with the giant MOK military earth orbit space station and the L3M two-launch lunar expedition using new lunar spacecraft (with a podsadka approach to deliver the crew to earth orbit by the new 7K-S!).