This page no longer updated from 31 October 2001. Latest version can be found at Soyuz 7K-LOK

LOK Lunar Orbiter
LOK Lunar Orbiter
The Soyuz 7K-LOK lunar orbiter spacecraft to be used in the L3 lunar landing project complex.

Credit: © Mark Wade. 19,358 bytes. 497 x 178 pixels.

Other Designations: LOK, T1K. Article Number: 11F93. Manufacturer's Designation: 7K-LOK. Class: Manned. Type: Lunar orbiter. Nation: Russia. Manufacturer: OKB-1.

Soyuz 7K-LOKSoyuz 7K-LOK - Soyuz 7K-LOK manned lunar orbit spacecraft.

Credit: © Mark Wade. 16,758 bytes. 558 x 170 pixels.

The two-crew LOK manned lunar orbiting spacecraft was the largest derivative of Soyuz developed. The BO orbital module differed from the basic Soyuz in having the Kontakt lightweight docking system, a forward reaction control system module, and a cupola allowing the cosmonaut to make a manual visual docking with the LK lunar lander. The PO/AO service module was radically different from others in the Soyuz series. It featured the Block I propulsion system with a much more powerful engine and greater fuel capacity (required to put the spacecraft on the trans-earth trajectory from lunar orbit). Power was provided by Lox/LH2 fuel cells, also a first for a Soviet spacecraft (radioisotope nuclear batteries were advocated by some factions during development but not adopted).

Soyuz LOKSoyuz LOK - Soyuz LOK lunar orbiter.

Credit: © Mark Wade. 6,574 bytes. 576 x 208 pixels.

In the N1-L3 lunar scenario, the LOK, the LK lunar lander, and the Block D deceleration stage would be inserted into lunar orbit by a burn of the Block D. One crewman would spacewalk from the LOK to the LK. After separation from the LOK, the Block D stage, still attached to the LK, would act as a 'lunar crasher' stage, decelerating the LK to 100 m/s four kilometres above the surface (later in development this was reduced to 1.5 to 2.0 km). The LK itself would accomplish the final lunar descent. After surface exploration, the single cosmonaut would return to the LK, which would propel itself back into lunar orbit for docking with the waiting LOK and transfer of the crewman and surface samples. The single cosmonaut aboard the LOK would perform the rendezvous and docking with the LK. This gave the design a little 'wiggle room' in case of weight growth. After the cosmonaut from the LK transferred himself and the lunar samples to the LOK, the LK would be cast off and the LOK would make the engine burn to take the crew back to earth.

LOK reaction controlLOK reaction control - The upper half of this item is the ODOP (Orientation and docking engine section) of the LOK, mounted at the top of the orbital module. The cone at top was had grapples for snagging the hexagonal grid of the large disk on top of the LK. Propellants for the orientation and maneuvering engines were in the tanks in this section. The bottom half of this item is similar to a test installation used on the Soyuz 7K-L1S destroyed in the several N1 launches.

Credit: © Mark Wade. 47,373 bytes. 368 x 520 pixels.

No LOK’s ever flew in space (the flight of Cosmos 382 was previously identified as an LOK test, but it has since been identified as a Soyuz 7K-L1E/Block D). A Soyuz 7K-LOK was said to be the payload for the last N1 test (which ended in the explosion of the booster). Only misidentified remnants of LOK's are exhibited today, at the MAI Museum in Moscow and the Korolev School and Energia Museum in Korolev.

LOK Descent ModuleLOK Descent Module - LOK Descent Module and Orbital Module

Credit: © Mark Wade. 52,944 bytes. 353 x 582 pixels.


Craft.Crew Size: 2. Design Life: 13 days. Orbital Storage: 13.00 days. Total Length: 10.1 m. Maximum Diameter: 2.9 m. Total Habitable Volume: 9.00 m3. Total Mass: 9,850 kg. Total Propellants: 3,152 kg. Primary Engine Thrust: 3,388 kgf. Main Engine Propellants: Nitrogen tetroxide/UDMH. Main Engine Isp: 314 sec. Total spacecraft delta v: 1,100 m/s. Electric system: 0.80 total average kW. Electric System: 250.00 total kWh. Electrical System: Fuel cells.

Soyuz 7K-LOK Chronology

01 June 1961 Moon program go-ahead in response to U.S. start Program: Lunar L1. Launch Vehicle: N1.

Chelomei heads circumlunar project. Chelomei asked by Khruschev to begin design for booster and spacecraft for circumlunar mission (UR-500 Proton and LK-1). No authorization for lunar landing program, although Korolev, Yangel, and Chelomei all begin booster designs.

LOK Descent ModuleLOK Descent Module - LOK Descent Module detail. The ablative material is far thicker than on the standard Soyuz descent module for the reentry from lunar distances at twice the energy as that from earth orbit.

Credit: © Mark Wade. 49,816 bytes. 394 x 580 pixels.

04 October 1963 Gagarin identified as head of lunar cosmonauts Program: Lunar L1. Launch Vehicle: N1.

Tereshkova announces in Havana that Gagarin head of lunar cosmonaut team.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module, view down from top of spacecraft toward Soyuz descent module.

Credit: © Mark Wade. 49,201 bytes. 389 x 584 pixels.

01 August 1964 Full scale development of Soviet manned lunar flyby and landing projects authorised. Launch Vehicle: N1, Proton 8K82K.

Central Committee of the Communist Party and Council of Soviet Ministers Decree 655-268 'On Work on the Exploration of the Moon and Mastery of Space--piloted LK-1 circumlunar and L3 lunar landing projects and the Ye-6M lunar lander' was issued.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module, view of main control panel dummy.

Credit: © Mark Wade. 40,433 bytes. 578 x 389 pixels.

03 August 1964 Full lunar program go-ahead Program: Lunar L1. Launch Vehicle: N1, Proton 8K82K.

Command number 655-268 was issued by Central Committee of Communist Party. Chelomei was to develop the LK-1 for the manned lunar flyby while Korolev was to develop the N1-L3 for the manned lunar landing. First launch of the N1 was to be by the first quarter 1966, with manned lunar landings in 1967 to 1968. Reprioritization led to work being stopped on Korolev's Zvezda 6 man orbiting weapons platform by mid-1965, after a huge mockup had been built. Chelomei as usual issued the advanced project for the LK-1 on the same day. The decree also ordered development of the three-stage version of his Proton UR-500 to boost the LK-1 around the moon.

LOK Block I forwardLOK Block I forward - View of the dome covering the pressurized instrument compartment of the LOK.

Credit: © Mark Wade. 57,540 bytes. 577 x 397 pixels.

10 February 1965 L3 draft project approved. Launch Vehicle: N1.

Interdepartmental Scientific-Technical Council on Space Research (MNTS-KI) Decree 'On approval of the L3 draft project' was issued. The decree followed a review by a Keldysh-led Academy of Sciences state commission the previous December. The decree moved the first flight of the N1 to the end of 1966.

LOK Block I sideLOK Block I side - View of the LOK Block I. Noticeable are the fragile radiator panels, and the large maneuvering thrusters at the forward end. The large cylindrical devices are fuel cells.

Credit: © Mark Wade. 48,508 bytes. 580 x 398 pixels.

06 September 1965 Problems in lunar projects addressed. Launch Vehicle: N1.

Ministry of General Machine Building (MOM) Decree 'On delays in work on piloted lunar programs' was issued.

01 September 1966 N1-L3 manned landing profile approved. Launch Vehicle: N1.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module, view up from the entry hatch from the Descent Module to the ceiling. Note air conditioning equipment.

Credit: © Mark Wade. 67,879 bytes. 397 x 575 pixels.

Central Committee of the Communist Party and Council of Soviet Ministers Decree 'On approval of the N1-L3 mission profile' was issued.
14 September 1966 N1 plans approved. Launch Vehicle: N1.

Academy of Sciences Decree 'On course of work on the N1-L3' was issued.

LOK Block I sideLOK Block I side - View of the LOK Block I instrument/rocket module. The fragile radiators, arrayed around the main fuel tank, extended away from the body of the spacecraft in flight. The silvery instrument section has numerous patch panels for connecting external wiring. The tapered interstage with stringers connected to the Soyuz descent module. Large 'mooring' thrusters arrayed around this section provided high-authority maneuvering capability for the LOK in its rendezvous and docking with the LK.

Credit: © Mark Wade. 59,078 bytes. 577 x 403 pixels.

17 September 1966 Competing lunar landing designs to be evaluated. Launch Vehicle: N1, UR-700.

Military-Industrial Commission (VPK) Decree 'On creation of a commission to compare the UR-700-LK-700 and the N1-L3' was issued.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module, equipment above the EVA hatch. These mockups are at the location of the spacesuit hookups for the single cosmonauts spacewalks to and from the LK.

Credit: © Mark Wade. 43,953 bytes. 391 x 572 pixels.

01 November 1966 Delays in Soviet manned lunar programs addressed. Launch Vehicle: Proton 8K82K / 11S824, N1.

Decree 'On lag of work on the N1-L3 and UR-500K-L1 programs' was issued.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module, closeup of cupola for use of cosmonaut in docking with LK.

Credit: © Mark Wade. 19,383 bytes. 254 x 326 pixels.

10 November 1966 Lunar coordination problems Program: Lunar L3. Launch Vehicle: N1.

Kamanin diary complains of lunar coordination problems.

16 November 1966 Government go-ahead for N-1 use in lunar program Program: Lunar L3. Launch Vehicle: N1, UR-700.

S5.51 LOK engineS5.51 LOK engine - Side view of the Isayev S5.51 engine used in the Soyuz 7K-LOK lunar orbiter.

Credit: © Mark Wade. 60,916 bytes. 385 x 511 pixels.

Mishin's draft plan for the Soviet lunar landing was approved by an expert commission headed by Keldysh. The first N-1 launch was set for March 1968. At same meeting, Chelomei made a last ditch attempt to get his revised UR-700/LK-700 direct landing approach approved in its place. Although Chelomei had lined up the support of Glushko, and Mishin was in a weak position after Korolev's death, Keldysh managed to ensure that the N1-L3 continued. However continued design work on the LK-700, the UR-700 booster, and development of the RD-270 engine were authorised.

S5.51 LOK engineS5.51 LOK engine

Credit: © Mark Wade. 64,079 bytes. 555 x 390 pixels.

01 February 1967 Government approves landing on moon by end 1968 Program: Lunar L3. Launch Vehicle: N1.

Soviet government approves plan to land cosmonaut on moon by end 1968. N-1 test plan approved, envisioning third quarter 1967 as beginning of flight hardware construction. Fall-back project would be manned circumlunar mission. First manned L1 mission imagined as early as June 1967. First N1 launch by March 1968.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module control station above hatch entrance. Main controls are on the blue panel; the green panel are radio controls.

Credit: © Mark Wade. 60,786 bytes. 396 x 577 pixels.

15 March 1967 CIA reports on Soviet space developments Program: Lunar L3. Launch Vehicle: N1.

CIA reports accurately development of N-1, Almaz, Proton, etc.... even states 100,000 kg large space station in development for launch by N-1 by 1969. CIA does not expect lunar landing until early 1970's.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module, view down from top of spacecraft toward Soyuz descent module.

Credit: © Mark Wade. 21,648 bytes. 195 x 292 pixels.

14 November 1967 N1-L3 moon landing schedule revised. Launch Vehicle: N1.

Decree 'On revision of the timetable for the N1-L3' was issued.

01 March 1968 Originally planned N-1 first launch Program: Lunar L3. Launch Vehicle: N1.

LOK Orbital ModuleLOK Orbital Module - LOK Orbital Module, docking control station. The maneuvering panel and controls were located where the grey dummy panel is. The cosmonaut would look through the cupola to accomplish manual docking with the LK after its return from the lunar surface.

Credit: © Mark Wade. 56,090 bytes. 395 x 575 pixels.

Slipped to May.
13 March 1968 Lunar cosmonaut training program approved. Launch Vehicle: N1.

Decree 'On approval of the training program for lunar cosmonauts' was issued. This incuded the final moon landing plan.

LOK Descent ModuleLOK Descent Module - LOK Descent Module and Orbital Module. Note the cupola at the left top of the Orbital Module.

Credit: © Mark Wade. 48,259 bytes. 358 x 574 pixels.

31 December 1968 18 cosmonauts in lunar training Program: Lunar L1. Launch Vehicle: N1.

Gagarin, Komarov, Nikolayev, Bykovsky, Khrunov, Gorbatko, Voronov, Kolodin, Popovich, Gubarev, Artyukhin, Gylyayev, Belousov, Kolesnikov, Volynov, Doborvolsky, Voronov, Zhobolov.

N1-L3 shroudN1-L3 shroud - N1-L3 shroud separation test

Credit: RKK Energia. 14,389 bytes. 308 x 238 pixels.

26 June 1971 N-1 6L Program: Lunar L3. Launch Site: Baikonur . Launch Vehicle: N1. FAILURE: First stage failed.

Superbooster failure of N1 serial number 6L. This was a substantially improved vehicle, incorporating filters in the propellant lines to prevent any foreign objects from getting into the pumps. The shape of the tail of the booster was modified, and ventilation and refrigeration systems were added to keep the engine compartment cool. It was painted white overall to reduce temperatures while sitting on the pad. After liftoff and ascent, an axial rotation was introduced by gas dynamics interactions of the thirty engines with the air slipstream. The launch vehicle developed a roll beyond the capability of the control system to compensate. and began to break up as it went through Max Q. Control was lost at 50.2 seconds into the flight and it was destroyed by range safety a second later. The engines functioned well and did not shut down up to the point of vehicle destruction. No functional payload was carried. It has been stated that this launch did not have a working launch escape system.

LOK Docking AssyLOK Docking Assy - Closeup view of LOK orientation engine unit and docking assembly at Korolev School.

Credit: Jakob Terweij. 42,694 bytes. 493 x 386 pixels.

01 September 1972 L3 terminated.

Decree 'On termination of production work on the L3' was issued.

23 November 1972 LOK Program: Lunar L3. Launch Site: Baikonur . Launch Vehicle: N1. FAILURE: Failure.

LOK at KorolevLOK at Korolev - LOK exhibited at Korolev School. Living module and re-entry vehicle are at foreground; in background is Block I instrument/propulsion unit covered with heat radiating panels.

Credit: Jakob Terweij. 53,648 bytes. 384 x 580 pixels.


LOK-LK DrawingLOK-LK Drawing - Unusual diagram of LOK and LK lunar craft in docked configuration, with bottom view of LK. Korolev School.

Credit: Jakob Terweij. 22,627 bytes. 639 x 158 pixels.

LOK OM InteriorLOK OM Interior - View of the interior of the LOK re-entry vehicle at the Korolev School. This is the only known photograph of this part of the spacecraft. A form-fitting crew couch is seen at lower left and the single visible control panel at center.

Credit: Jakob Terweij. 72,270 bytes. 581 x 387 pixels.

LOK Capsule InteriorLOK Capsule Interior - The LOK Block I propulsion unit at Korolev. The delicate white radiator panels have been bent over the years. The cylinder outershell and flared base of the LOK are missing; the smaller cylinder at top is the engine unit.

Credit: Jakob Terweij. 28,709 bytes. 285 x 480 pixels.

Panorama MAI ExhibitPanorama MAI Exhibit - Panorama of launch vehicles and spacecraft exhibited at Moscow Aviation Institute.

Credit: Ed Cameron. 31,933 bytes. 640 x 233 pixels.

Isayev and KorolevIsayev and Korolev

Credit: © Mark Wade. 8,099 bytes. 244 x 191 pixels.

N1-L3 drawingN1-L3 drawing - N1-L3 drawing at Kaluga

Credit: © Mark Wade. 25,536 bytes. 560 x 101 pixels.

L3 CutawayL3 Cutaway - Dimensioned Russian cutaway drawing of L3 manned lunar landing complex.

15,454 bytes. 223 x 965 pixels.

LOK OverheadLOK Overhead - Overhead view of LOK lunar orbiter.

20,358 bytes. 470 x 305 pixels.

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Last update 12 March 2001.
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© Mark Wade, 2001 .