Angara-A5V launch vehicle
First proposed at the end of 2014, the new variant of the Angara-5 rocket designated Angara-A5V (or Angara-5V for short) will employ a new hydrogen upper stage to boost its payload to the low Earth orbit to around 35 tons, while preserving the dimensions of the five boosters on the first and second stages. As a result, the Angara-5V could be built instead of the much more expensive Angara-7 variant, which relied on a larger-caliber central booster requiring a separate launch pad.
History of the project
At the end of 2014, the onset of economic recession in Russia prompted the Kremlin to slash its space budget, making the planned development of a super-heavy rocket unaffordable. At the beginning of 2015, the new leadership at Roskosmos evaluated the alternatives and restricted the agency's launch vehicle ambitions to upgrades of its brand-new Angara-5 rocket. The agency indefinitely postponed not only the super-heavy rocket, but also less radical upgrades of the Angara that would require increasing the diameter of its standard URM-1 boosters to build more powerful configurations such as Angara-7 and its derivatives with payloads of up to 50 tons.
As an alternative, GKNPTs Khrunichev proposed a low-cost configuration, designated Angara-A5V, where "5" identified the number of boosters on the first and second stages and "V" stood for "vodorod" -- a Russian for hydrogen. The introduction of hydrogen fuel on the third and fourth stages of the standard Angara-5 rocket promised to increase its payload to around 35 tons, according to various estimates. The proposal was also endorsed by RKK Energia, the chief human space flight contractor. (745)
On March 12, 2015, Roskosmos announced that its Scientific and Technical Council, NTS, had recommended GKNPTs Khrunichev in cooperation with RKK Energia to develop preliminary proposals ("avantproyekt") for the Angara-5V rocket and its possible adaptation for prospective transport and manned ships as well as other payloads for missions to the vicinity of the Moon and expeditions to its surface. The resulting project would have to be presented to an inter-agency commission for the assessment, Roskosmos said.
Unlike the super-heavy booster, whose applications would be largely limited to the ambitious manned space program, the 35-ton-class vehicle could play multiple roles, delivering commercial, military and scientific payloads and thus spreading the cost of its development across a wide range of programs. The newly appointed NTS chairman Yuri Koptev confirmed that fact during his first conversation with journalists in March 2015, saying that the Russian military had already faced mass limitations on some of its spacecraft. As a result, the project could count on the support of the Ministry of Defense. With an estimated payload from 12 to 12.5 tons to a geostationary transfer orbit, Angara-5V would also be well positioned to compete on the commercial market with the American Delta-Heavy rocket, capable of carrying between 12 and 14 tons and with the latest upgrades of the Ariane-5, which was promised to deliver between 10 and 11 tons to the same orbit.
All components of the Angara-5V rocket would be compact enough to be transported by rail to Vostochny, where the planned launch facility would need a modest amount of redesign to accommodate a taller and heavier rocket. The rail transportation limited a diameter of all components to 4.0 meters or even 3.9 meters, when considering its travel through a Severo-Muiskiy tunnel in the Far East. Finally, the rocket would need relatively small-scale infrastructure for production and fueling of the rocket with liquid hydrogen.
If approved for full-scale development, Angara-5V would be launched from a second launch pad planned for the Angara family of rockets in Vostochny. (744)
What Angara-5V might look like?
At the time when the concept of the Angara-5V was first announced, no architecture or design features of the rocket had been revealed. However only few upgrade options were thought to be available, given the assumed requirement of preserving the dimensions of the URM-1 booster stages from the original Angara-5 rocket in order to rely on the existing production line.
In March 2015, Roskosmos identified following upgrades of the Angara-5 rocket, which would boost its payload capacity to 35 tons to the low Earth orbit:
In addition, few other payload-boosting upgrades are thought to be available. For example, special refueling lines (known as cross-feeding lines) could be routed from four boosters of the first stage to the central booster of the second stage. As a result, the core booster would have nearly full tanks by the time the four strap-on boosters separated during launch. This measure could increase the payload for Angara-A5V to 38 tons by some estimates.
Finally, the RD-191 engine could be replaced with its more powerful successor -- RD-195 that can reportedly produce around 230 tons of thrust at sea level. The nozzle of the RD-195 engine could be equipped with a special extension to increase its performance at high altitude, bringing the payload to 40 tons, according to unofficial estimates made by veteran rocket engineer Dmitry Vorontsov.
In April 2015, Roskosmos promised that Angara-5V would carry up to 38 tons, however behind the scene, engineers were already seeing potential challenges in the design, which could degrade the payload to 35 tons.
By the end of 2015, the proposed Angara-5V was apparently 1.8 tons short of carrying the PTK spacecraft with its MOB-DM stage. At the same time, the rocket would also need extra 2.2 tons of payload in order to lift the LVPK lunar module along with its own MOB-DM space tug. To fulfill this mission, the rocket's total payload would have to be brought to 39.8 tons.
As of beginning of 2015, NPO Energomash was yet to prove that its RD-191 engine would be able to meet the requirements of the Angara-5V rocket for a higher thrust. Necessary upgrades to the engine would be a subject of the study during the preliminary work on the project. (744) In August 2015, NPO Energomash confirmed that the company had began work on a modified version of the engine designated RD-191M on the assignment from GKNPTs Khrunichev.
The design of the newly developed third stage for the Angara-5V was expected to be similar to previously proposed hydrogen boosters, such as such the second stage designed for the cancelled Rus-M launch vehicle or the UKVB booster that was previously proposed as the third stage for the Proton-M2 and for the Angara-5/UKVB rockets. In March 2016, First Deputy Director at GKNPTs Khrunichev Aleksandr Medvedev confirmed that it had been decided to equip the URM-2V with a pair of RD-0150 engines.
In most missions, the Angara-5V would also be equipped with a KVTK fourth stage, performing the role of a space tug, which would carry its payload from an initial parking orbit to a higher altitude or into an escape trajectory on the way into deep space. The development of the KVTK stage had already been commissioned by Roskosmos as a replacement to the Briz-M and Block-D stages on the original Angara-5. However to send the manned PTK NP spacecraft into the lunar orbit, a more powerful version of the KVTK space tug would be required, possibly using multi-engine configurations. Such designs were previously considered for upper stages of the Angara-7 variant.
Lunar orbit insertion stage
To support human missions to the lunar orbit, Angara-5V would also need the fourth stage or a space tug, which would be employed to ease the PTK NP spacecraft, lunar orbital station or lunar lander into the orbit around the Moon. This component could be based on the Block DM stage propelled by kerosene and cryogenic oxygen or on the Fregat stage, powered by storable propellant. In the initial technical proposal for the Angara-5V rocket, RKK Energia did offer the use of its Block DM in the project. (745) Block DM also appeared to be depicted in the scale model of the Angara-5V rocket displayed in the Kremlin during a meeting between President Vladimir Putin, Deputy Prime Minister Dmitry Rogozin and Roskosmos head Igor Komarov on April 13, 2015.
Cost and development schedule
At the beginning of 2015, the development of the Angara-5V rocket was estimated at 37 billion rubles, not including flight tests, as oppose to 700 billion rubles required for the super-heavy booster. According to Yuri Koptev, projected budgets for the Federal Space Program and Launch Site Development Programs from 2016 to 2025 would be able to afford the development of the Angara-5V rocket. As of beginning of 2015, Angara-5V was expected to reach the launch pad around 2022, possibly, following the introduction of the Angara-5P rocket. (744) By April of the same year, in the draft of the Federal Space Program, FKP-2025, the first launch was penciled for 2023.
On April 22, 2015, Yuri Koptev said that the preliminary proposal for the Angara-5V rocket would be ready by the end of the year. In turn, the head of RKK Energia Vladimir Solntsev said that his company would complete a preliminary proposal for the integration of the PTK NP spacecraft with the Angara-5V rocket within six months. (745)
According to the head of Roskosmos Igor Komarov, Angara-5V would be developed in cooperation between GKNPTs Khrunichev in Moscow, FSKB Progress in Samara and RKK Energia in Korolev.
Despite its pragmatism, the plan to build Angara-5V did not go without controversy. Obviously, the decision to develop a low-cost alternative to the super-heavy launcher also meant that the rocket industry would lose billions of rubles in the following decade.
Within days after the go-ahead to the Angara-5V, an anonymous op-ed appeared in a fiercely nationalistic publication of the Russian military industrial complex with a stinging attack on the proposal. (743) The article seemed to be authored by sources close to Vitaly Lopota, a recently dismissed head of RKK Energia, who fought long and hard for the approval of the super-heavy rocket.
The critique charged that the use of Angara-5V in the lunar program would be too expensive and would slow the development of prospective technologies for the financial benefit of particular businessmen and bureaucrats, apparently pointing at GKNPTs Khrunichev and its American subsidiary International Launch Services, ILS.
Probably referring to the construction of a lunar base, the critic claimed that 40 Angara-5V rockets would be required to accomplish the lunar exploration program, versus only eight super-heavy rockets with a payload of 75 tons.
In the style of the current anti-western hysteria in Russia, the critic then claimed that the NTS decision was influenced by the Americans, supposedly in an effort to stunt a competitor to NASA's super-heavy launcher, SLS, and thus to give the US a strategic national-security advantage.
Although the key mission for the Angara-5V rocket would be to compete on the commercial market and deliver heaviest military payloads, the rocket could be considered for a role in human missions beyond the Earth orbit.
A single Angara-5V rocket would be enough to place a modified Soyuz spacecraft into orbit around the Moon, while two such launchers could support a Soyuz-based expedition delivering two cosmonauts onto the lunar surface, according to preliminary estimates made at RKK Energia. (744) However as many as four Angara-5V rockets would be required to put a larger crew on the surface with the use of the 20-ton next-generation PTK NP spacecraft. (745) Not surprisingly, the PTK development team apparently received a request in April 2015 to reduce the mass of the spacecraft by at least two tons.
Under the second scenario, two rockets would blast off within three days from each other carrying the lunar module and its space tug. After linking up in the Earth orbit, the space tug would send the lander toward the Moon. Within a month, another pair of rockets would have to lift off, carrying the PTK NP spacecraft with a crew of four and their space tug. Cosmonauts would link up with their space tug in the Earth orbit and then make another rendezvous with the lunar lander in the orbit around the Moon. Two crew members would then transfer into the lander and make a sortie onto the lunar surface.
Responding to potential critics, Koptev said that Russia's extensive experience in conducting rendezvous and docking operations would minimize the risk of this complex scenario. (744)
As of April 2015, the circumlunar mission was expected around 2025, while lunar landing could take place in 2029.
A number of private and informal initiatives within the Russian space industry and a wider space-advocacy community, such as the Luna-Sem (Luna7) proposal from a private startup Lyn Industrial, were lobbying for such low-cost schemes for a number of years.
The question remained whether such scenarios would be affordable and practical under worsening economic conditions and engineering challenges facing the Russian space program.
By the end of 2015, funding cuts in the Russian space budget required to subdivide Angara rocket upgrades within the Amur project into two phases. Only the first phase, which funded the deployment of the Angara-5/KVTK and Angara-5P rockets at the site, would reach flight tests in 2021, during the Federal Space Program extending from 2016 to 2025. The completion of the second phase, which would see the first unmanned launch of the Angara-5V rocket from Vostochny, was postponed from 2024 to beyond 2025.
The industry completed the preliminary proposal for the Angara-5V rocket by February 2016 and the review by the Scientific and Technical Council at Roskosmos reportedly endorsed the design on April 13, 2016. But due to its political significance, the project was to be sent to the Russian president Vladimir Putin for his personal approval. At the time, top Russian space officials, including First Deputy Director at GKNPTs Khrunichev Aleksandr Medvedev and the Head of Roskosmos Igor Komarov said that the rocket would be ready for use in Vostochny "by 2025."
At the same time, Roskosmos warned that it could take up to a year to make a determination whether the human exploration program would be relying on the Angara-5V rocket or it would be necessary to return to the concept of the super-heavy launcher, which had to be suspended at the end of 2014 due to funding problems.
Even after 2016, when Angara-5V was essentially rejected as a carrier of lunar expeditions, GKNPTs Khrunichev still believed that the project had a chance to survive due to the interest of the Russian military in boosting the overall payload capacity of the Angara family.
In 2017, Roskosmos promised the first launch of Angara-5V in 2027. That date was confirmed in an article by the former Designer General at GKNPTs Khrunichev Aleksandr Medvedev published in the Kosmonavtika i Raketstroenie magazine in 2018. However in October 2018, Head of Roskosmos, Dmitry Rogozin said that the launch pad for the Angara rockets in Vostochny would be modified for the launches of the 5V variant by 2026. Rogozin re-confirmed the 2026 deadline for the first launch of the Angara-5V during his visit to the PO Polyot production plant on June 22, 2019. In April 2020, Rogozin once again emphasized that the service gantry at the future launch facility in Vostochny would be able to accommodate not only the Angara-5 variant but also a version of the rocket with a hydrogen booster serving as the third stage.
After Rogozin's visit to KB Khimavtomatiki in Voronezh (developer of the RD-0150 and RD-0146 engines) on July 14, 2020, Roskosmos said that he had directed the company to accelerate the work on the new generation engines burning hydrogen and methane with the goal of developing the Angara-5V rocket no later than 2025 and a new commercial methane-propelled vehicle to replace the Soyuz-2 series.
By the end of 2020, the development of the Angara-5V variant was at a virtual standstill at the preliminary design level due to lack of funding.
As a result, industry sources indicated that the first projected launch of the Angara-5V variant slipped from 2026 to 2027 or 2028, at the earliest. Even those dates would depend on resumption of funding.
In the meantime, the growing realization in 2020 of the challenges facing the super-heavy rocket project prompted Roskosmos to take a second look at the Angara-5V variant as the carrier of the nation's lunar exploration plans. Whether that interest would translate into real budget for the prospective launch vehicle remained to be seen at the end of 2020. There were reports that in mid-December 2020, Rogozin approved the development of a lunar expedition architecture relying on Angara-5V rockets. During his visit to Angara's production plant in Omsk on December 19, Rogozin promised to begin testing of the Angara-5V variant in 2027.
Known specifications of the Angara-5V rocket as of 2015:
Planned Angara-5V missions as of April 2015:
Deputy Prime Minister Dmitry Rogozin (left) and Roskosmos head Igor Komarov (center) demonstrate President Putin scale models of the Angara-5 rocket and the descent module of the next-generation manned spacecraft, PTK NP, on April 13, 2015. Click to enlarge. Credit: Russian government
An artist rendering of the Angara-5V rocket at liftoff. Click to enlarge. Copyright © 2015 Anatoly Zak
A lunar lander conceptualized during 2015 to be compatible with the Angara-5V rocket. Click to enlarge. Copyright © 2016 Anatoly Zak
A circa 2001 design of the Angara-5/UKVB rocket featuring cryogenic third and fourth stages. Hydrogen fuel tanks are shown in blue. Such a configuration was promised to deliver 28.5 tons to the low Earth orbit. Credit: GKNPTs Khrunichev
Scale models of the 11D56 (KVD-1) engine proposed for the UKVB stage on the Proton-M2 and Angara-5 rockets and RD-0146 engine (right) proposed for the second stage of the Rus-M rocket. Copyright © 2011 Anatoly Zak
The RD-0120 engine for the Energia rocket could be a point of departure for the development of RD-0150 engine to propel the URM-2V stage on the Angara-5V rocket. Click to enlarge. Copyright © 2000 Anatoly Zak
A possible depiction of the RD-0150 engine.