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Soyuz-5 development in 2017


Sea Launch in search of a way out

In 2017, the Russian space industry continued behind-the-scene efforts to revive the mothballed Sea Launch complex and to find potential new applications for the floating spaceport. Russian and Ukrainian officials looked at a politically viable way to resume the production of the Zenit rocket, while Roskosmos began work on a new booster compatible with the Sea Launch facilities. In parallel, experts in human space flight made an initial assessment of a possible role for the ocean-going launch pad in the support of Earth-orbiting space stations.

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Sea Launch vessels moored at their home port of Long Beach, California.

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Zenit production jumpstart still faces hurdles

According to the Yuzhmash production plant in Dnipro, Ukraine, in April 2017, it had received a contract from the S7 Sea Launch Limited for the production of 12 Zenit rockets.

Almost a year after the Russian airline S7 Group took over the troubled Sea Launch venture, the first payments from Moscow for the production of Zenit rockets has reached Yuzhmash. However the jumpstart of production still faced serious hurdles, industry sources said. Yuzhmash officials gave their Russian counterparts at the S7 Group a list of components which are no longer available for the Zenit. One of the most important items on the list is the ignition systems produced in the Lugansk region which has been taken over by pro-Russian rebels and remains practically cut off from the rest of Ukraine. The igniters burning black powder are used to initiate small solid-propellant motors which generate reverse thrust to facilitate the safe separation of the first and second stages during the ascent of the Zenit rocket to orbit.

According to industry sources, the S7 company has been so far unable to secure the delivery of Russian equivalents of the necessary hardware and materials, probably due to lack of permissions from Moscow. Instead, the S7 Group asked KB Yuzhnoe to organize the production of missing components in Ukraine. However, in the case of black powder, launching its production in Ukraine would not make economic sense due to lack of other applications beyond the very small amount required for the ignition systems, one source said.

Some observers question whether the S7 company has a real motivation to see the Sea Launch venture through because the airline with no prior experience in the space launch business ended up with the Sea Launch assets in its lap likely under pressure from the Kremlin.

Sea Launch seeks help from Roskosmos, proposes new applications

The private owner of the Sea Launch venture has proposed Russia's state-owned space industry to cooperate in the revival of the mothballed service. On Sept. 21, 2017, Sergei Sopov, Director General of the S7 KTS, which owns Sea Launch, sent a draft of a potential cooperation agreement to the Head of Roskosmos State Corporation Igor Komarov.

The document outlined areas of possible cooperation between S7 and Roskosmos on commercial launches from the sea-based facility. In addition to an offer to rejoin the competition on the international launch market, the document listed several new applications for the Sea Launch which would expand its potential customer base beyond foreign communications satellite operators.

First of all, the agreement would open the Sea Launch platform operating from the Equator to the Russian satellite developers, who until now have relied almost exclusively on launch vehicles based in Kazakhstan or Russia. In addition, the S7 and Roskosmos would cooperate in the development of a new-generation cargo ship which could lift off from the Sea Launch to re-supply manned orbital stations. Finally, S7 proposed to study a multi-functional orbital complex, which would be based on the Sea Launch. The new system would be used for launching, docking, assembling, fueling and servicing the Earth's orbiting vehicles, including those which were designed to climb to higher orbits or even head into interplanetary space.

In the long term, S7 envisioned refurbishing the Sea Launch platform to host the new-generation medium-class launcher developed in Russia and replacing the Ukrainian-built Zenit.

Human space flight experts evaluate Sea Launch potential

Given the latest proposals from the owners to employ the troubled Sea Launch for human space flight, in the fall of 2017, Roskosmos commissioned its experts to evaluate the feasibility of such a radical idea. First of all, engineers looked at potential cargo missions to the International Space Station, ISS, originating from the Sea Launch platform.

In the case of the yet-to-be-built Soyuz-5 rocket operating from Sea Launch, it would be possible to send a 17-ton cargo ship toward the ISS, instead of the 7-ton Progress-MS vehicles currently serving the Russian Segment of the station. Based on the estimate that the mass of the actual supplies could reach up to 50 percent from the mass of the spacecraft itself, Sea Launch-based Soyuz-5 could haul around eight tons of cargo to the ISS in each mission. Annual demand for deliveries to the Russian Segment of the ISS reaches around 11 tons and preliminary estimates show that the new-generation Russian Orbital Station, ROS, (proposed to succeed the ISS), will require around nine tons of supplies per year.

Based on these numbers, engineers compared the required annual flight frequency of a hypothetical cargo ship launched by the Soyuz-5 rocket based on Sea Launch with the existing Progress-MS spacecraft launched by Soyuz-2-1a rocket and with a prospective TGK PG cargo vehicle, which would be launched on Soyuz-2-1b:

Sea Launch-based cargo ship
ISS, Russian Segment
4 flights per year
3.2 flights per year
1.4 flights per year
Russian Orbital Station, ROS
3.3 flights per year
2.6 flights per year
1.1 flights per year

As in many previous proposals to replace Progress with larger cargo ships, the Sea Launch-based supply vehicle would certainly cut the cost of cargo delivery, but sharply reduce the flexibility of orbital operations due to low frequency of the flights. In addition, the Sea Launch-based cargo operations were found to present their own unique drawbacks.

For example, the pre-launch processing of cargo ships currently involves irreversible fueling operations, which have to be performed after all the dry cargo has already been loaded into the ship's pressurized section. Currently, the fueling of the cargo ship takes place around 10 days before launch. In addition, the fully loaded spacecraft has to be carefully weighted and balanced for a safe ride into orbit. As a result, the Sea Launch complex would have to be upgraded with specialized fueling equipment, while toxic propellant components would have to be shipped from Russia to the home port of Sea Launch vessels in the United States. It means that the processing team would also have to load most of the cargo and then weigh and balance the vehicle before the spacecraft could board the Sea Launch ship and before it set sail to its launching point on the Equator.

Given previous transportation of satellites by Sea Launch, the cargo ships could probably be adapted to do the same, but, currently, there is an option to upload a last-minute minor items into the spacecraft on the pad around three hours before liftoff. However, the highly automated Sea Launch complex does not provide access to the rocket, and thus, without modifications, it would prevent fast-reaction delivery of certain items, such as biological samples or other perishable materials.

Also, because the station-bound spacecraft have to undergo leak checks at the launch site, the Sea Launch complex would have to be equipped with a vacuum chamber. Alternatively, the vehicles could be transported in sealed containers doubling as vacuum chambers.

In the end, engineers concluded that additional analysis would be needed to evaluate the possibility of adapting cargo missions for the Sea Launch complex.

Launching space station modules

Human space flight experts also looked at the option of launching future Russian space station components, such as the airlock and inflatable modules from the Sea Launch platform. Because these pieces of the station are still on the drawing board, they could theoretically be enlarged for the Soyuz-5 rocket from their current configuration sized to fit into the Soyuz-2 rocket. However, such a major expansion from 7 to 17 tons would have to be justified and properly funded, because it would mean a higher price tag for the program. In the 1980s, Soviet add-on modules for the planned Mir-2 space station were sized for the Zenit rocket with similar lifting capabilities to those of the proposed Soyuz-5.

Similarly to cargo supply missions, launching space station modules from the Sea Launch platform, would require upgrading the facility with vacuum testing and on-site fueling capabilities.

The jury is still out

Despite a mixed initial verdict from human space flight experts, Roskosmos had little choice but to share responsibility for the Sea Launch complex with the S7 company. In November, the two sides signed a memorandum of intentions on the joint development and use of the Sea Launch complex.

In the meantime, the Sea launch vessels remain anchored at their home port of Long Beach, California, deprived of their crews and out of action...

Unbooked flights

The Sea Launch flight manifest was posted without much fanfare on the Russian-language version of the corporate web site for the Sea Launch venture, apparently, shortly after the successful campaign to launch the Zenit rocket with the Angosat-1 satellite on Dec. 26, 2017.

Although the schedule detailed all the launch dates with accuracy to a month, it listed no customers or their payloads to be carried during any of these missions. It was unclear, whether Sea Launch was in negotiations with any potential riders at the time.

The description accompanying the schedule also said that the permanent office of the S7 company had been established at the home port of the Sea Launch vessels in Long Beach, California, to handle the tasks of re-activating the facility and resuming launch operations. Based on estimates from a monitoring group, the complex would be ready for operations in 2018, the S7 Group said.

The company also announced that the Russian firms RKK Energia, Roskosmos State Corporation and the Ukraine-based Zenit manufacturer Yuzhmash would be partners in Sea Launch, which would be managed from Moscow by the S7 KTS company, also known as S7 Space.

Sea Launch flight manifest as of December 2017:

Mission Launch date Payload
1 2019 December ?
2 2020 April ?
3 2020 July ?
4 2020 December ?
5 2021 March ?
6 2021 June ?
7 2021 September ?
8 2021 December ?
9 2022 March ?
10 2022 June ?
11 2022 September ?
12 2022 December ?


Next chapter: Sea Launch in 2018


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The article by Anatoly Zak; Last update: October 18, 2018

Page editor: Alain Chabot; Edits: September 1, November 15, December 11, 2017

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In 2017, Russian industry initiated work on the Soyuz-5 rocket family, which would have a Sea Launch-based variant. Copyright © 2017 Anatoly Zak


In 2017, Russian engineers considered enlarging a new-generation cargo ship to make it compatible with a Sea Launch-based Soyuz-5 rocket. Click to enlarge. Copyright © 2016 Anatoly Zak


Personnel of the Sea Launch complex is usually withdrawn from the platform to the command and control vessel, allowing the fully automated process to take over the final countdown and liftoff operations. Click to enlarge.


Currently, there is no access to the top of the Zenit rocket on the Sea Launch platform before liftoff. Click to enlarge.