A Sound of Thunder: The Rise of the Soviet Superbooster

Hi everyone. No Interlude this week, I’m afraid, so the next update will be a regular Post on Friday.

Regarding the L3M design presented in the last update, all of the details are as per OTL plans at the time of N-1’s cancellation in 1974 (i.e. the L3M-1972) . Lacking any detailed images of those plans (the best photo of real hardware I’ve found is the crude mockup in the background of the image below - indeed, very “space egg”!), I had to extrapolate many of the visual details, but the description in the text is pretty much unchanged. It’s mostly based on information from Brian Harvey’s book “Soviet and Russian Lunar Exploration” and Anatoly Zak’s “Russia in Space” (now apparently out of print). Harvey’s book was particularly useful, and included the surprising detail that Glushko was developing a powerful monopropellant engine for the lander. I have also gone with this ITTL, despite the excellent record of Yuzhnoye’s Blok-E LK engine.


For the visual details I extrapolated, many of these came from the later Glushko RLA and Energia-launched LEK designs (from which I borrowed the acronym), with others borrowed from L3 spacecraft.

Regarding the question on how much monoprop was used, I don’t have my references to hand, but think I do have landing/takeoff masses for the GB-2. Unfortunately, it’s not clear how much of the mass difference is propellant, and how much due to the mass of the landing stage that was left behind on the Moon. I would also expect that a lot of consumables for the stay on the surface would also be carried in the Landing Stage, but again, I don’t have any numbers on those.

That Re-Entry Capsule may prove useful in the event of a Solar storm. Was that a consideration?

This has also occurred to me, especially considering the system is intended to be exposed on the surface for a full lunar day, but again, hard data on the OTL design is not available.

On the topic of the collapse of the USSR, this is something that will be explored in Part 2 of the timeline, and I’ve not yet fully mapped it out. I have some thoughts on how this will play out ITTL, but still need to write the details and fully work through the impacts on the space programme. One thing I’ll note is I’ve confirmed the USSR will end, but I haven’t said what will replace it.

I do agree with those who’ve pointed out that a lot of the details of the OTL collapse were very contingent upon the personalities involved and the specific circumstances in which they were forced to act. To take a very late PoD, the OTL dissolution would not have happened in the same way if the 1991 August Coup had not happened, or if it had been followed through more forcefully, or if it had failed as per OTL but Yeltsin hadn’t taken advantage of the aftermath to emasculate Gorbachev, or if the leaders of the other three “Nuclear Republics” hadn’t agreed to back Yeltsin against Gorbachev, or… Well, the point is made :) So rest assured, the TTL end of the USSR won’t be a cut-and-paste of OTL, just with Groza instead of Energia.
Here are the L3M numbers from Harvey. He quotes the GB-2 vehicle's "Ascent Stage" as having a mass of 19.5 tonnes when launching from the Moon, and 8.4 tonnes during the coast back to Earth, implying 11.1 tonnes of HTP propellant. Zak states that the whole L3M spacecraft had a mass on launch of 25 tonnes. The RD-510 is quoted by Harvey as having a thrust of 12 tonnes, referencing an Air & Cosmos article "Les moteurs secrets de NPO Energomach" by Christian Lardier from 2004.
Data from Anatoly Zak book "Russia in Space"
L3M is 25 metric ton space craft for 14 day stay (later 30 days max ) foe 3 cosmonaut on moon
it use two N1F launches with 100 metric ton payload
first launch the Block SR and block D2 (48 metric tons) the hydrolox Bock SR launch D2 to Moon were it goes into orbit
15 days later
second N1F launch Block SR with L3M into low and there to Moon orbit were it rendezvous with Block D2 (a enlarge Block D)
both dock and beginn decent to Surface were Block D2 detach from L3M a kilometre over surface

It's unclear how the L3M enter Lunar orbit, but i guess that huge amount of HTP propellant was to burn with kerosine

In 2001: a Space a Time Odyssey
i used different approach the N1F got second and third upper stage with hydrolox engines that launch Block D2/L3M to moon
here the Block D2 bring L3M into Moon Orbit and begin landing completed by decent engine of L3M
the 3 Cosmonauts live in there Zarya Space capsule (3,7 meter diameter) for 14 day on lunar surface
while volume between external hull and Zarya, is with support equipment like airlock etc.
at end of mission the Accent stage takes Zarya capsule back to Earth, leaving the rest behind on Moon.
Regarding how L3M entered LLO

Perhaps the Block Sr was used for that? Being lighter than the Block D2, perhaps that's how it could?
You are both assuming that some time in the early 90's all 15 Soviet Republics end up as independent countries. Without wanting to get too current politics that is far from certain, especially with a PoD this early. Ignoring the needle threading option of having the Soviet Union successfully reform itself into a sustainable entity* you can very easily have the Soviet Union come to an end and be succeeded by a more successful CIS-expy including multiple former Soviet Republics. Certainly keeping Russia, Kazakhstan and Belarus together seems more like something that happens in more "Soviet dissolution alternative timelines" than not.

*which does not have to be a democracy
Pretty much exactly what I was thinking--at least re the "'Stans." Ukranians, along with the Baltic peoples, had some pretty strongly separatist sentiments and retaining them would require either very convincing conciliation by the Russians or some strong-arm methods. I am not sure Ukraine could not be persuaded fairly easily with a certain degree of autonomy and a great deal of respect shown them by the "Great Russians." After all, in Soviet days certain Ukrainians enjoyed a lot of prestige and power in the USSR as a whole; Nikita Khrushchev was ethnically Russian, but born and raised in Ukraine and he had a lot of Ukrainian cronies. These were Party apparatchiks of course; anti-Communist Ukrainians would hardly be moved in favor of continuing union with the Russians by that, nor am I very sure how far out of favor Ukraine as a whole might have fallen after Khrushchev's ouster from power. But anyway, sufficiently far-sighted and respectful Russian leadership could conceivably get the support of enough factions of Ukrainians to keep the union.

The Baltics are another story; they would stay unified only at the point of a gun, as they were taken in in the first place. I don't know about the Caucasian republics.

The Central Asian republics on the other hand did not so much escape the Russian system OTL as they were in fact cast out. The way the Soviet planned economy was managed, these republics were required to produce certain resources and thus prevented from producing others, and on those terms, it looked from a Russian point of view that Russia was subsidizing them. I don't know how much simple crude racism also influenced the Russian decision to simply turn them loose. But prior to the collapse of the USSR, there was far less dissident separatism in these republics than in the eastern European possessions. Again then, the Russians certainly have a chance to keep the Central Asian republics federated with Russia--more easily than they could hang on to Ukraine for sure.

For the sort of rocket business @Michel Van was alluding to, keeping Kazakhstan tied to Russia is only a partial solution (though a big one!) as I suppose Ukraine would be where some of those parts needed were made. But perhaps keeping Ukraine federated is doable, and anyway the post-Soviet space program could get along just fine without the Baltic republics or the Caucasian ones I would think--keeping the latter at least allied with and friendly to the Russian federation would be more advantage to the space program than the former actually, as they extend the range of Russian operations farther south.

The most important difference from OTL would be keeping Kazakhstan united with Russia, and that is very doable even on pretty close to OTL's ideological track through the '90s and beyond. I don't think the Russians would be very successful trying to strongarm the Kazakhs against their will, but persuading them (and the real trick versus OTL, the Russians themselves) the partnership is mutually beneficial is quite possible.

I suppose that a union that started out on sheer momentum from Soviet ways could go sour over time and separatism might be a rising tide in Kazakhstan, if the Russians blow it--which they might well do of course. But it is also possible they continue to be united to the present day and beyond--again this is a separate question from whether Soviet Communism can survive, let alone prosper. Mind, I do think the ongoing union is more logical under Communist premises, but these are liable to go extinct soon enough; whether a post-Communist Russian regime can partner with other ethnicities depends on how heavily the newer regimes lean on raw nationalism versus some other organizing principle.

Given how bloody the Soviet breakup was (nothing compared to what was generally feared would happen if the Communists thought they were losing their grip to be sure, but violent and messy all the same) I like TLs where there is less disintegration, but of course wanting continued union on a humane and enlightened basis is a taller order than just achieving it by ongoing brutality.
Here are the L3M numbers from Harvey. He quotes the GB-2 vehicle's "Ascent Stage" as having a mass of 19.5 tonnes when launching from the Moon, and 8.4 tonnes during the coast back to Earth, implying 11.1 tonnes of HTP propellant.
To push 8.4 tonnes through a 3 km/sec delta-V from Lunar surface to Earth transfer orbit is a mass ratio of 2.32, which implies an Isp in seconds of 363, corresponding to effective exhaust velocity of 3562 m/sec.

That's actually pretty high even for a very efficient and advanced ker-lox engine, and even using methane instead of long-chain hydrocarbons for fuel is pretty ambitious. There is simply no way such mass ratios can be squared with using hydrogen peroxide monopropellant!

To be fair there is also no way to square it with using HTHP as oxidant with kerosene either of course; I figure Isp with hydrogen peroxide would be about 80 percent or less of that from the same fuel burned with pure oxygen. Such engines would achieve Isp in the ballpark of 270-290 sec--much better than 160 or so, but not good enough to achieve these quoted mass ratios.

I can see peroxide being useful in auxiliary roles--to drive the turbopumps for a ker-lox or meth-lox engine say, thus decoupling the pumps from the mass flow of main engine propellants which should give stronger throttling authority. Or as propellants to provide variable thrust atop main engines burning ker-lox at a steady rate for constant thrust or slowly varied thrust.

Clearly though, it is impossible to get the necessary delta-V from just decomposed hydrogen peroxide alone.

Meanwhile, if we were to junk the idea of HTHP being a major component of the main thrusters for landing and ascent, as I said, they already had the engine to be used for these roles for LK, using kerosene and oxygen, ready to hand. If LK were 5 tonnes on launching for ascent then four such engines should provide similar lift-off performance on a 19.5 tonne LEK.

So why not just use that engine, or rather 4 of them, or 6 throttled back to 2/3 thrust allowing for a single-engine out paired with shutting down the opposite engine to regain balance to maintain the same landing and launch profiles on just 4 remaining engines? It would mean storing LOX on the Lunar surface for weeks but this is probably doable.

The Isp of that engine might not be quite high enough to meet the quoted specs and thus more mass would be propellant and less "payload," but not a lot more or less I'd think.
Perhaps the Block Sr was used for that? Being lighter than the Block D2, perhaps that's how it could?
according Astronautix
Capable of five restarts and 11 days of flight. Could insert 24 metric tons into lunar orbit or 20 metric tons into geosynchronous orbit.

Shevek23 made interesting point on return Delta-v = 3km/s2, needed specific impulse of 362 sec under mass ration 2,3.
HTP/kerosine can reach 300 sec max. Kerolox also

according Astonautix on L3M program
The DU engine block would perform the same ascent stage duties as the Block E of the original LK.
Block E is a pressure fed Engine with N2O4/UDMH propellants with specific impulse of 315 s
sadly no info on block DU propellants or engine
After a bit more digging, it seems RD-510 may in fact have been a HTP/hydrocarbon bipropellant engine, according to Asif (though it's unclear which hydrocarbon, listed simply as "CxHy"). This appears to be reflected by astronautix, but I'm not able to access the site at the moment to confirm. So this looks like an error in Harvey, and by me.
Looking at the delta-v needed, I think 3km/s may be an overestimate. Atomic Rockets Mission Table shows Moon-EML1 as 2.52km/s. Once past EML1, you'd basically fall back to Earth (though maybe Kerbal - or Nurbel - players could confirm!). This would suggest an Isp of around 305s, which is just over what's been suggested as the maximum. It could be the mass figures aren't quite correct, or Glushko got a bit more oomph out of the RD-510. It's worth digging further.
In any case, I'll go back and do an edit on the GB-2 being monoprop when I get 5min, as this indeed looks to be wrong.

Regarding how L3M entered LLO

Perhaps the Block Sr was used for that? Being lighter than the Block D2, perhaps that's how it could?

Blok-Sr stages were used to put the GB1 and GB2 into their lunar orbit, though I don't have any numbers on how low that orbit was.
You need very high expansion nozzles for such a high Isp, IIRC. The highest Isp kerolox engine that I know of has an Isp of around 350 seconds. RD-170 according to Astronautix which was developed between 1973 and 1985, (its variant RD-171 is used on the Zenit boosters for Energia), has an Isp of 337 seconds.

You could go with UDMH/LOX conversions for R-7 derived engines, and get you fairly close to the 363 seconds Isp performance. IIRC Korolev was working on a propane/lox engine for the LK lander, so that could be also used and it would be better-performing IIRC.

pretty sure CxHy is syntin or C10H16.
You need very high expansion nozzles for such a high Isp, IIRC. The highest Isp kerolox engine that I know of has an Isp of around 350 seconds. RD-170 according to Astronautix which was developed between 1973 and 1985, (its variant RD-171 is used on the Zenit boosters for Energia), has an Isp of 337 seconds.

You could go with UDMH/LOX conversions for R-7 derived engines, and get you fairly close to the 363 seconds Isp performance. IIRC Korolev was working on a propane/lox engine for the LK lander, so that could be also used and it would be better-performing IIRC.

pretty sure CxHy is syntin or C10H16.

I've seen numbers of 362s Isp for OTL's Buran OMS - which used GOX/Sintin - which I suspect must be right at the uppermost end of what such a bipropellant mix is capable of. Even subtracting 7-8 seconds of it and it should still be plausible for it to work on L3M.

And given all the images of L3M I've ever come across shows it using chemical bipropellants - admittedly very few, and from a single source - it does appear to me that L3M may always have been intended to have its engines powered as such.

Looking at the delta-v needed, I think 3km/s may be an overestimate. Atomic Rockets Mission Table shows Moon-EML1 as 2.52km/s. Once past EML1, you'd basically fall back to Earth (though maybe Kerbal - or Nurbel - players could confirm!).

IIRC when the Apollo CSM/LM were heading to the Moon, they crossed the EML1 at about 2,000 Kmph - about 556 m/s - performing the LOI burn some 3-3.5 days after TLI. Adding some more delta-v - 400-500 m/s worth - to reduce transit/coast time is something I'd expect them to do.

Variables...gotta love 'em...
Post 8: Dawn


Post 8: Dawn​

TV Anchor:
If you think you saw a new star at about 8:30 tonight, it was the Soviet Zarya space station. The station and its three cosmonauts passed directly over DC at 8:34 tonight, travelling northwest to southeast. The National Space Institute used the event to point out the growing gap between the US and Soviet space efforts.

CUT TO: EXT. DAY. A residential suburban street in Washington DC.

Space Expert:
Right now, the Soviets have a very dynamic program, a well thought-out program, and indeed the United States is foundering in a whole mess of technical and leadership problems. The idea of what we’re trying to do is to let the public know that, yes, the Soviets have something and it’s up there, and they should be aware of that, and the American program is in trouble.

- WJLA Local Evening News, 30th April 1975[1]


The long-discussed Multi-module Cosmic Base Station (MKBS) could trace its lineage all the way back to the Orbital Station (OS) concept proposed by Korolev in 1960 as a military base in space. This later evolved into the MKBS, which was to form the centrepiece of an expansive Multi-module Orbital Complex (MOK), a constellation of military satellite systems serviced on orbit by human crews operating out of the MKBS. Despite much of this military role being assigned to first Chelomei then Glushko under the Almaz project, the MKBS had remained on TsKBEM’s books as an authorised project, waiting for the N-1 launch vehicle that would make it possible. With Groza reaching something like routine operations, and conscious of the success of the competing Almaz space stations, in mid-1973 Mishin had ordered an acceleration of efforts to put the first MKBS station into orbit.

The starting point for Mishin’s initial MKBS station was the OS-1 design that had reached the mock-up stage in 1969. Using one of these mock-ups as the basis of a pressure hull, the design was modified to use solar panels rather than the originally planned nuclear reactor, which was not expected to be ready for flight until 1978 at the earliest. Systems adapted from Soyuz or borrowed from Almaz were used to fit out the station, with the Soyuz 7K-OKS variant providing crew transfer services. Although the longer term plan was to support crews of six-to-nine cosmonauts and resupply with a new, automated Soyuz derived cargo ship, this first station would host a single docking port, with the bulk of the supplies needed to support up to five missions of three cosmonauts being launched with the station. This was made possible by the increased size and launch mass of the station, as well as the shortage of scientific experiments available to fill the hull at short notice.

By the middle of 1974, the MKBS No.1 design had been frozen and assembly was well underway. With an empty mass of 55 tonnes, the 21m long station was composed of a series of compartments, comparable in many ways to the Almaz station. At the rear was a 1.7m long Propulsion Compartment, containing engines for orbit maintenance and attitude control. This was attached to the main Working Compartment, a cylinder 8.6m long and 5.3m wide, which housed propellant, life support systems and consumables, plus scientific equipment. This transitioned down to the Habitation Compartment, 2.75m wide and 10.2m long. As the name suggests, this compartment housed crew facilities for three cosmonauts, as well as the flight control consoles. Four large solar arrays were mounted on the exterior of the Habitation Compartment, supplying up to 10kW of electrical power to the station. Finally, there was a small Transfer Compartment, mounting the SSVP port and Igla antennas that would be used to dock visiting Soyuz ferries.

Mishin was gearing up for a launch of MKBS-1 in mid 1975, but his plans for larger, modular follow-on stations were dashed in September 1974 when a joint decree of the Central Committee and the Council of Ministers commanded the merger of the MKBS programme with the Almaz Phase 2 project, with overall responsibility for Soviet space stations transferred to Glushko’s NPO Energomash. Mishin would be permitted to launch his first station as a demonstration and propaganda tool, but follow-on stations would be built by Glushko.

Despite the blow this decision dealt to morale at TsKBEM, work continued on the station module, and by March 1975 the giant module was completing final checks and was moved to the MIK building at Site 112 to start integration with Groza vehicle number N1-10L. A month later, on 18th April 1975, MKBS module No. 1 lifted off from Pad 37. On the side of the fairing (the first for Groza lacking an escape tower) was written the station’s name: Zarya.



Zarya’s arrival and commissioning in orbit was monitored from the new Flight Control Centre in the Moscow suburb of Kaliningrad, close to TsKBEM headquarters. An expansion of the old Coordination and Computing Center for interplanetary probes, the new facility had been developed to support the Apollo-Soyuz Test Project, and was far more impressive than the old centre at Yevpatoriya in Crimea. The new control centre had debuted in February 1975, supporting the Soyuz 15 ASTP rehearsal mission, and was now to be the primary control facility for all future Soviet crewed space missions. The opening of the new control centre had also been marked by a change of ground control’s callsign from “Zarya” to “Moscow”. This would prove helpful in avoiding confusion when calling the new space station.

With Zarya safely in orbit and functioning nominally, attention quickly turned to the launch of Soyuz 16 with the station’s first crew. As Zarya was a TsKBEM project, two of the three crew members were civilian engineer-cosmonauts, led by Mission Commander Vladislav Volkov and Research Engineer Oleg Makarov. They were joined by Air Force cosmonaut Anatoli Voronov as Flight Engineer, who had served on the back-up crew for the Soyuz 13 mission to Almaz 2, and so had trained extensively on that military station’s systems. Both Makarov and Voronov would be making their first spaceflight, whilst Volkov had previously flown as the Flight Engineer on Soyuz 7. Operating under the callsign “Ruben” (Ruby), the crew’s training had been more chaotic than was normal, as the compressed schedule to get Zarya ready for launch had seen many last-minute changes in the experiments carried and their layout on the station. Often, modifications made as the station was being prepared failed to make it into the training mock-up, raising concerns that the crew were not ready to support the mission. Nevertheless, when the State Commission met on 23rd April, they confirmed both crew and spacecraft as ready to fly.

Soyuz 16 lifted off from Baikonur’s Site 1 launch pad at 07:55 on Friday 25th April 1975. The Soyuz-U rocket operated smoothly, delivering the 7K-OKS spacecraft into an orbit co-planar with Zarya, but around 30km lower. The crew reported feeling fine, and later that day began manoeuvring to put Soyuz on a transfer orbit to the station. After a sleep period, the final approach commenced early the next day, approaching to within 7km of the station by 07:00 on 26th April. At this point the Igla system was expected to establish radio contact with the station, but once again the automatic docking equipment proved unreliable, refusing to lock up on Zarya. After consultations with the Chief Operative and Control Group (GOGU), Volkov was commanded to begin a slow manual approach, firing the Soyuz’s SKD engine to approach at 10m/s. At a distance of 5.6km Igla finally achieved radio lock, and the automatic systems took over for final approach, and mechanical contact was achieved at 08:12. Just over two hours later, the docking hatch was opened and Volkov and Voronov entered Zarya’s Transfer Compartment.



The first few days on board were focussed on activating and checking out the station’s systems. The crew found the station’s vital systems mostly working as expected, but several of the experiments experienced problems, the most serious of which was the failure of the cover of the KATE-UO stereographic camera to open, making the instrument unusable.

In terms of living space available, all three cosmonauts expressed how spacious the workshop interior was compared to Soyuz, or even Almaz, and Zarya’s impressive size was frequently emphasised during their regular “Cosmovision” television broadcasts. Although a few pre-recorded television programmes had been broadcast from the Almaz stations, the frequent five- to ten-minute live telecasts from Zarya were a new innovation for Soviet missions, and helped to boost the profile of the station with the Soviet public and the wider world. Subtitled highlights from the transmissions proved surprisingly popular in US television news clips, as the mission was taking place during the build-up to the much anticipated Apollo-Soyuz joint flight, and so Western audiences were eager to learn more about the Soviet space programme.

Despite its hurried construction and a general lack of cooperation between the TsKBEM and Energomash design bureaux, the designers of Zarya had been able to take advantage of many lessons learnt from the three Almaz missions. Voronov in particular commented favourably on the small individual ‘cabins’ each cosmonaut was provided with, compared with simply attaching a sleeping bag to any convenient wall, as had been the practice with Almaz. Other aspects that had been improved included keeping the cosmonauts on a regular 24-hour cycle, rather than the shorter ‘day’ used on Almaz-1 to keep synchronised with ground contact windows. This avoided unnecessary disruption to the crew’s circadian rhythms, greatly improving their productivity and morale. Communications sessions with TsUP were generally shorter and more focussed, avoiding micro-management of the cosmonauts’ time or bombarding them with trivial or repetitive queries.

Time management was particularly important for the crew of Soyuz 16 due to the large number of experiments carried on board. In an effort to prove the value of the station, Mishin and his engineers had crammed as many experiments as possible into Zarya. However, whilst the large size of the station meant that it could physically host almost twice as many experiments as Almaz, the number of cosmonauts available to operate them remained the same. As originally conceived, Zarya was to have included three docking ports on the Transfer Compartment, allowing regular crews of six supported by uncrewed cargo ships, but the rush to complete the station had led to this capability being deleted.
Also, the switch from nuclear energy to solar panels to provide electricity meant that power to operate these payloads had to be rationed. Some on-going experiments with moderate power needs, such as the Oazis plant growth experiment, were able to operate continuously, but most could only be run during dedicated sessions on specifically scheduled days. The time available was further reduced by the size of the station and late changes in the layout of the hardware, meaning the cosmonauts often had to spend an hour or more finding and preparing the equipment before the experiments could start. The short training time and sheer number of experiments meant that even more time was taken up in reading instructions, much to the frustration of the scientists on the ground.

Despite these problems and frustrations, by the second week of the mission the cosmonauts had settled into a steady routine, and the mission proceeded relatively smoothly for the next month. The cosmonauts made observations of the Earth and stars at multiple wavelengths, conducted experiments in plant growth and materials science, and underwent a wide range of biomedical examinations, on top of a vigorous exercise regime. Experience with the Almaz missions had demonstrated the importance of exercise in maintaining health and allowing for a quick re-adaptation to full gravity on return to Earth, and the extra volume available in Zarya had allowed for a wide variety of exercise equipment to provided, including a treadmill, exercise bike, and elasticated “weight machines”. Cosmonauts on Almaz missions had noted that use of the treadmill in their stations tended to set up vibrations that affected astronomical observations, or could even cause sympathetic oscillations in the solar arrays. In contrast, the crew of Zarya found this to be far less of a problem, thanks to a combination of an updated treadmill design with built in vibration damping, and the increased mass and differing harmonics of the station. High-precision observations still needed to be conducted in periods when none of the crew were exercising, but the solar arrays were never put at risk by a cosmonaut’s jogging.

After eight weeks on-orbit, it was time for the crew of Soyuz 16 to pack their belongings and prepare for their return to Earth. Although luxurious compared to previous Soviet spacecraft, a number of minor malfunctions and inconveniences meant that the cosmonauts were eager to get home. For example, all three cosmonauts complained that the station interior remained overall quite cool, hovering just under 20℃ regardless of the setting of the control thermostat. Their diet had also become quite monotonous, with no opportunity for re-supply missions to mix up the menu. This was something that the next crew would also have to contend with, as all vittals for the three planned missions had been launched with the station.

After setting the station for automatic operation and shutting down all unnecessary equipment, the crew returned to their Soyuz capsule, sealing the hatch to the station at 07:15 on Sunday 22nd June, 1975. Undocking came less than an hour later, followed by a textbook re-entry and landing in a remote region of the Kazakh SSR two hours before sunset that same day. Volkov, Makarov and Voronov were celebrated as Heroes of the Soviet Union, their “Cosmovision” broadcasts having made them famous throughout the USSR and across the world.

Unfortunately, Soyuz 16 would prove to be the only crewed mission to Zarya. Late in the night of 14th July, while the flight controllers and engineers at TsUP were focussed on the ongoing Soyuz 17 ASTP mission, one of Zarya’s on-board experiments, which should have been switched off before the crew departed, shorted out. The short triggered a fire, which quickly spread throughout the station. By morning, when mission controllers realised that the station had missed its last two contact periods, Zarya was dead in space. As Leonov and Stafford shook hands in orbit, TASS quietly informed the world that operations with the Zarya space station had been successfully concluded, with all mission objectives fully met.

Despite the disappointing loss of Zarya, 1975 continued to be a busy year for TsKBEM, as for the second year running two Groza launches were planned. The second, N1-11L, was aimed beyond Earth orbit, and even past to Moon, towards one of the N-1’s original objectives: Mars.

The Soviet Union had a poor record of Mars exploration. Up to the end of 1973 a total of fifteen Mars missions had been launched by the USSR, with four departing Earth in 1973 alone. Of these missions, nine were total failures, and only one, the Mars-5 orbiter, would prove to be fully successful. Of the partial successes, there were some notable achievements, including the first soft landing on the planet by Mars-3 in December 1971 (although this triumph was muted when the lander fell silent after just 110 seconds on the surface). However, next to the results obtained by the American Mariner probes - especially Mariner-9, which entered orbit in November 1971 - the Soviet programme did not compare well. With NASA planning to send twin landers to Mars at the 1975 launch window, the Soviets hoped that the capabilities provided by Groza would give them a chance to catch up, and perhaps surpass, US accomplishments.

In 1970, Georgy Babakin at NPO Lavochkin directed his engineers to start designing a Mars sample return probe, using the N-1 as the launch vehicle. This would follow on from the successful Luna-16 mission that returned samples from the Moon in September 1970, but would be much larger in mass, duration and complexity. The Mars 5NM sample return probe would have a starting mass in low Earth orbit of a whopping 98 tonnes. The 16 tonne lander was too heavy to rely upon parachutes, and so after using a deployable shield to aerobrake from interplanetary speeds, four rocket engines would be used to perform an automated thrust-borne soft-landing on the surface. A two-stage return rocket would put the 750kg cruise stage into Mars orbit, where it would wait up to ten months for the planets to align before starting its journey home. Finally, a 15kg return capsule would plummet through Earth’s atmosphere to deliver its payload of Martian soil to the waiting scientists. After a three year voyage, that 98 tonne probe would have brought back 200 grammes of Mars dust.

Recognising the complexity of this mission profile, Babakin proposed to first test some of the key technologies with a simpler, though still impressive, mission to land a rover on Mars. Called Mars-4NM, this would use the same deployable aeroshell and rocket powered descent as 5NM, but the payload would instead be a modification of the Lunokhod rovers that had been the first wheeled vehicles on the Moon.

Originally intended to launch in the 1973 opportunity, the teething problems experienced by Groza, as well as difficulties in developing the probe, delayed the launch, and the probe - now named Mars 8[2] - lifted off on 12th September 1975 on Groza launch N1-11L. The launch and Earth departure were successful, but contact was lost with the probe three months later, before it reached the Red Planet. The cause was never found, but was assumed to be a failure of the electronics systems, and the back-up probe on Earth was subjected to additional testing with the hope of launching a repeat of the mission during the 1977 launch window.



[1] Based upon an OTL news piece from St Louis local TV, interviewing Michael Mackowski
of the Space Frontier Society in 1987 about the Mir space station. However, the opinion that US spaceflight is mired in technical and political problems is pretty much evergreen.

[2] IOTL the Mars series ended with Mars 7, which launched in 1973. The spacecraft made a successful flyby of Mars, but unfortunately so did the lander, which missed the Martian atmosphere and continued on into space. IOTL, no other Mars missions were launched by the USSR until 1988, with the twin Phobos probes. These also mostly failed, with only the Phobos 2 orbiter partially meeting its objectives before going silent. Russia tried to break the hoodoo in 2011 with Fobos-Grunt, but this mission was left stranded in Earth orbit when its upper stage failed.
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First two pics, it looks to me like part of the Zarya Station isn't enclosed in the fairing - given its diameter at that part, I can see why.

Nice to see a render of the N1 being raised into position, not too many of those ^_^

But performance/reliability-wise, looks to be about where it should be, seeing that Zarya didn't take long to wind up an orbital carcass - admittedly thanks to equipment being left on when it shouldn't have - and Mars 4NM never lasting long enough to make it to Mars.

Quality Control it seems, is still needing a lot of work doing there.

And a nice touch on the little detail of the US (at least the public) thinking the Soviet Space Effort is way ahead of where it actually is. Should the Truth comes out...
Ever since learning about the 4NM and 5NM mission proposals, I always thought that the Soviets must have been out of their minds on some high-grade stuff when they proposed them.

"Ah, yes comrade, the logical next step now that we've experienced precisely zero significant successes with our Mars program is to launch a far larger and more complex mission, dwarfing anything the Americans have done, without making sure that we've actually cured the reliability and quality control problems that have plagued the program to date! Surely this will not result in an embarrassing and costly failure!"

"Comrade Babakin, that sounds like a great idea! Also, wow, have you ever noticed how wonderful hands are? Hands!"
Ever since learning about the 4NM and 5NM mission proposals, I always thought that the Soviets must have been out of their minds on some high-grade stuff when they proposed them.

"Ah, yes comrade, the logical next step now that we've experienced precisely zero significant successes with our Mars program is to launch a far larger and more complex mission, dwarfing anything the Americans have done, without making sure that we've actually cured the reliability and quality control problems that have plagued the program to date! Surely this will not result in an embarrassing and costly failure!"

"Comrade Babakin, that sounds like a great idea! Also, wow, have you ever noticed how wonderful hands are? Hands!"
Nothing's embarrassing if you just write it off as "Cosmos-42069 on heliocentric orbit."

I'm kind of impressed by the sheer numbers of N1 launches that will be happening ITTL. They must be getting some serious economies of scale on the engines. Though I wonder if they won't want to start launching probes in pairs again to have redundancy in case of in-flight failure.
Great updated as always. I was looking for the @ from whom made the renders you use and was like "wait since when the brazilian space agency does this?".
That Zarya look like TMK study for manned fly by station from 1960s

and seems that Mars-4NM had same faulty Transistors that plagued the final Mars probes in 1973...
as I suppose Ukraine would be where some of those parts needed were made
While this is true, It's probably easier for state industries to relocate if the USSR/CIS is economically stronger and is going to leave Ukraine. In fact, it does not necessarily have to be economically stronger, just willing to spend a little bit to get the industries into a CIS country.
Looking at the delta-v needed, I think 3km/s may be an overestimate. Atomic Rockets Mission Table shows Moon-EML1 as 2.52km/s. Once past EML1, you'd basically fall back to Earth (though maybe Kerbal - or Nurbel - players could confirm!).
Yes and no, but mostly no. If an object is at EM-L1, it has two hurdles to cross to get to an orbit that comes close enough to Earth for a Soyuz capsule to skim the atmosphere and be braked to a landing on Soviet soil...

1) it is still some moderate but still not inconsiderable depth into Luna's potential well. Of course all objects in the universe are in Luna's potential well, technically. Escape speed does not mean one ever totally "escapes" a gravity well, but rather that one attains enough energy to keep receding from it indefinitely.

2) the greater factor to consider is the need to lower the angular momentum so as to enable an object to pass near Earth at all.

I was hoping to find a cooler source to reference than Wikipedia, but anyway, we can look up there in the subsection called "solar system values" that EML1 lies at 326,400 km from Earth's center versus the Earth-Moon separation of 384,400 KM. So, since L1 tracks Luna's radial direction away from Earth but at a radius 85 percent as great, it follows that an object there is circling Earth at that percentage of the Moon's speed and at that radius--so the angular momentum of one kg relative to Earth parked there is the square of that ratio, or 72 percent, the angular momentum of one kg orbiting Earth at Luna's radius. The moon's orbital speed is about 1022 meters/sec on average, so at L1, an object there circles Earth at 868 m/sec. Keeping that angular momentum while passing near Earth at a radius of say 6460 km (82 km above the surface) would imply a speed of close to 44 km/sec--escape speed at such altitudes is a quarter that! The majority of those near 900 m/sec must be braked away to enable the orbit to drop down to skim the atmosphere.

Meanwhile, if L1 is at that given distance and the Moon's own center is at the greater distance, the difference between them is 58,000 km--which is much greater than the Lunar average radius of around 1730 or so KM to be sure, but even this fraction, about 1/33.5, of the 2.8 million Joules/kg of the Lunar surface potential is still almost 85 kJ/kg, This corresponds to a speed of 411 m/sec.

This low speed alone is enough to pretty well neutralize any savings of delta-V we might get by first ascending to L1 and then hoping to reach Earth from there, versus a direct ascent straight shot 3000 km/sec from surface directly to a transfer orbit back to Earth. But we can see the larger share of the problem is nullifying the large angular momentum versus Earth. Because we are adding energies we add squares of velocity and to get speeds, take the square root. So, actually the combined escape to Earth transfer trajectory will not be a lot greater than just the angular momentum reduction share alone--but that is still going to be well over 700 m/sec or so, closer to 900 all up I think.

right there then we have worsened rather than reduced the total delta-V versus my admittedly rough guesstimate for direct ascent.

Now surely you were not suggesting, first ascend to L1 and then go from there back to Earth. I think you will find though that there is no royal road from the Lunar surface back to Earth that does not involve pretty close to this guesstimate 3 km/sec one way or another.