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|Angara-5 to replace Proton
Not counting unapproved "paper" designs, the Angara-5 rocket, a.k.a. Angara-A5 or 14A127, will become the most powerful version within its family. For the first time since the dissolution of the USSR, Russia will acquire a space launcher which could deliver more payload than the nation's current workhorse Proton rocket. In many respects, Angara-5 was the reason the entire family was developed.
Angara-5 variants: The original version of the Angara-5 rocket with the Briz-M upper stage (left); its "beefed up" variant featuring the KVTK hydrogen-powered stage (2nd from left); Angara-5P (center) shown as a two-stage variant, which was later updated to a three-stage version; Angara-5V (2nd from right), featuring a hydrogen powered third stage adapted from the Rus-M project; it is also topped with the beefed up KVTK stage; (right): Angara-5V with the PTK NP spacecraft and Block DM-based upper stage. Copyright © 2015 Anatoly Zak
The Proton replacement
Incorporating all the latest achievements of the Russian rocketry, Angara-5 was designed as the main carrier of satellites for the Russian Ministry of Defense, for the Russian civilian space agency and for its commercial customers around the world. When launched from Plesetsk, Angara could deliver 24.5 tons of payload to the low Earth orbit, comparing to up to 22 tons carried by Proton to a similar altitude.
Unlike Proton, whose launches are only possible from Baikonur, thus holding Russia a hostage of its agreements with Kazakhstan, Angara would be based in Plesetsk, located few hundred kilometers north of Moscow. Unfortunately, due to the geographical location of Plesetsk, Angara-5 lost much of its payload advantage over the Proton. The Plesetsk-based Angara would be taxed particularly hard when carrying satellites to the equatorial (geostationary) orbit -- its main destination. While the Russian government could tolerate this situation for the sake of its strategic independence, the Angara would face an uphill battle on the international market for the most economical way of delivering commercial satellites. To resolve the problem, the Russian space agency, Roskosmos, considered building an entirely new launch site in the nation's Far East. However these plans had to be postponed after the priority had been given to the construction of a launch pad for a less powerful Soyuz-2 rocket.
Moreover, during a major strategy meeting in October 2013, the new head of Roskosmos Oleg Ostapenko called the Angara family a "dead-end project" and urged against huge spending required to bring Angara to Vostochny. It was unclear what Ostapenko hoped to replace Angara with, given the fact that the prospective Russian super-heavy booster was still on a drawing board. Such a rocket could hardly be practical for a commercial role, but its components could serve as a replacement for Angara, the same way booster stages of the super-heavy Energia rocket became a basis for the medium-class Zenit in the USSR. However the development of such a launcher would likely take years longer than the "duplication" of the Angara's launch pad in Vostochny. Still, Ostapenko was apparently willing to accept that. As of 2014, it was still unclear what route Roskosmos would ultimately take.
In 2015, a total cost of the Angara-5 development was estimated at 150 billion rubles (744) and around the same time, each launch was expected to cost from $95 to $105 million. In 2020, GKNPTs Khrunichev hoped that the full cycle of serial production of the Angara series in Omsk would allow to reduce the cost of vehicle from the current 7.0 billion rubles to 4.0 billion rubles by 2024, the company's annual report said. It appeared that the Russian Ministry of Defense had procured first four operational Angara-5 rockets at a rate of five billion rubles.
Design of the Angara-5 rocket
Angara-5 (industrial designation 14A127) would use four standard URM-1 boosters as the first stage and a single URM-1 booster as its second stage. A prototype of the URM-1 made three flights as a part of the South-Korean KSLV rocket and also propelled the Angara-1.2PP rocket in July 2014. The URM-2 booster would serve as the third stage. It also performed successfully during the flight of Angara-1.2PP. The additional upper stages on Angara-5 would be used to send satellites from their initial parking orbits to the geostationary orbit or into deep space. Initially, the Briz-M upper stage using toxic storable propellants would be employed, only to be replaced with a more powerful KVTK space tug, burning liquid hydrogen. Additionally, Roskosmos considered equipping Angara-5 with Block-DM upper stage for missions from Vostochny. When launched with Block-DM upper stage the rocket would be topped with a 14S75 payload fairing, while a version equipped with the KVTK upper stage would be using the 14S735 fairing.
By the time flight testing of the Angara-5 rocket started at the end of 2014, the launch vehicle was expected to have a capability of delivering around seven tons of cargo to the geostationary transfer orbit. Since some of the military satellites had already been too heavy for the launcher, GKNPTs Khrunichev proposed an upgraded version of the vehicle, known as Angara-5V. (744)
Angara-5 lifts off with four boosters of the first stage and a central booster of the second stage all igniting their RD-191 engines on the launch pad. After 47 seconds of ascent at full thrust, the RD-191 engine on the central booster throttles down to 30 percent of its capability. It enables the booster to conserve propellant and burn longer than its strap-on siblings. After the separation of four boosters 213 seconds into the flight, the core stage returns to full thrust and fire for a total of 325 or 329 seconds. It then separates with the help of small solid motors installed "backwards" at the very top of the rocket's transfer compartment. The URM-2 then ignites its RD-0124 engine to accelerate the payload section to a nearly orbital speed. In a typical mission, the URM-2 fires until T+750 seconds in flight and the upper (fourth) stage then completes the job with a short firing of its engine to enter an initial parking orbit with an altitude ranging from 180 to 250 kilometers. The same stage later restarts its engine to reach a variety of higher orbits, depending on a particular mission.
When launched from Plesetsk, Angara-5 was to be able to enter orbits with an inclination of 63, 76, 82.5 and 93.4 degrees toward the Equator. In case of missions to the geostationary orbit, the upper stages would have to conduct propellant-hungry maneuvers to tilt the orbital inclination from the initial 63 degrees to a near-equatorial plane.
Production and flight testing
As of July 2014, the first test launch of the Angara-5 rocket from Site 35 in Plesetsk was officially planned for December of the same year. The rocket lifted off on Dec. 23, 2014, and largely completed its flight program.
In mid-2014, the first deputy to Roskosmos head Aleksandr Ivanov told the Ekho Moskvy radio station that Angara-5 vehicles had already been ordered for launches of operational satellites scheduled in 2016 or 2017. In an interview with the ITAR-TASS news agency in August 2014, the head of GKNPTs Khrunichev Vladimir Nesterov said that during its second mission, Angara-5 would be carrying an operational payload, however the launch vehicle would officially remain in flight testing until 2020. As of beginning of 2015, the second rocket was expected to leave the assembly line by November of that year. (725)
The Russian Ministry of Defense was expected to be the first agency to formally adopt the Angara rocket, Nesterov said.
Nesterov admitted that at the beginning of flight testing, each Angara-5 had been twice as expensive when compared to the operational Proton rocket, however he expressed confidence that the price per launch would come down significantly as the launch vehicle enters mass production. However Angara-5 was not expected to fully replace Proton until the new rocket had completed its flight test program, (including six launches from Plesetsk), logged enough successful missions and received its hydrogen-powered upper stage, Nesterov said. Moreover, its entrance into the commercial launch market would depend on the availability of the new launch pad in Vostochny. Industry officials confirmed that in order to become economical, the Angara-A5 would have to launch all federal and all commercial payloads that Russia could win around the world.
In September 2014, officials at GKNPTs Khrunichev announced that by 2021 Angara-A5 would take over launches of all Russian government payloads, leaving Proton to deliver commercial missions. During its early operational life, Angara-A5 was expected to fly around five missions a year, reaching seven launches per year between 2023 and 2025. As the production of the Angara rocket grows, the manufacturing of Proton would decline:
In December 2014, Interfax quoted Nesterov as saying that five Angara-1 and five Angara-5 rockets would be launched until 2020, before the launch vehicle family would be formally accepted into armaments of the Russian Ministry of Defense (and declared operational by the civilian space agency).
In August 2018, Acting Deputy Director at Roskosmos Nikolai Sevastyanov, who also served as the Head of Board of Directors at GKNPTs Khrunichev, told the Kommersant newspaper that 12 Angara-5 rockets had solid contracts, but a total of 27 such vehicles were thought to be needed for the Russian Federal Space Program until 2027.
Although the development of the Angara-5 rocket was funded by the Russian military, the rocket was expected to play multiple roles in the Russian space program, including a commercial one.
However, by 2016, International Launch Services, ILS, the US-based marketing arm of GKNPTs Khrunichev, firmly decided to put off commercial missions of Angara-5 rockets until the introduction of the new launch complex for the family in Vostochny, which was not expected at the time until at least 2021.
The decision to postpone the commercialization was made after the company had extensively studied an option of launching commercial payloads on Angara-5 from Plesetsk. The analysis revealed that limitations of payload capacity, when boosting satellites to equatorial orbits from Russia's northern cosmodrome, would make Angara-5 unprofitable.
The prospects of commercial missions from Plesetsk were further complicated by serious logistical challenges. Unlike Baikonur, with its extensive infrastructure for the Proton rocket, the Russian military launch site in Plesetsk has never been set up for the delivery and processing of large commercial payloads, such as communications satellites.
As a result, ILS embarked on another round of upgrades to the Proton family, which would bridge the gap until the introduction of the new launch site for the Angara in 2020s. The hope was that by that time, the new-generation Angara rocket should have accumulated enough flight experience with military and Roskosmos' payloads for a confident entrance onto the commercial stage. As of 2020, the Angara's flight test program required six launches from Plesetsk and three flights from Vostochny, including launches of the first and second missions of the new-generation Orel spacecraft and the delivery of the Luch-5VM data-relay satellite.
In 2017, the Russian government identified the Angara-5M, as a cheaper, modified variant of Angara-5 customized for launching unpiloted satellites and based in Vostochny. The upgrades will include the introduction of composite materials and the new flight control system, enabling to deliver up to 25 tons into the low Earth orbit. At the time, Angara-5M was promised to make its first flight from Vostochny in 2021, however by 2019, that mission was not expected until 2023.
In June 2020, the head of KB Salyut Sergei Kuznetsov said that the first Angara-5 rocket for Vostochny was in production and that the second Angara vehicle slated to fly from Russia's new launch site would be a 5M variant.
Footage released in 2019 showed the main assembly hall in Omsk with components of URM-1 boosters which were likely intended for the third Angara-5 rocket (Vehicle No. 71753 - background) and the fourth Angara-5 (Vehicle No. 71754 - foreground).
Angara-5 booster mass specifications:
Known specifications of the URM-1 and -2 modules:
Evolution of the Angara-5 capabilities:
Payload capabilities of the Angara-5 rocket launching from Vostochny:
The very first Angara-5 lifts off on Dec. 23, 2014. Click to enlarge. Credit: Russian Ministry of Defense
Angara-5 sheds its four first-stage boosters during a ride to orbit. Click to enlarge. Copyright © 2014 Anatoly Zak
A scale model of the Angara-5 rocket with a hydrogen-powered upper stage unveiled in 2001. Copyright © 2001 Anatoly Zak
A scale model of the Angara-5 rocket with Briz-M upper stage unveiled in 2009. Click to enlarge. Copyright © 2011 Anatoly Zak
Angara-5 (left) and Angara-5P rockets as of 2013. Copyright © 2013 Anatoly Zak
A possible configuration of the Angara-5 rocket with a KVTK upper stage circa 2013. Credit: Roskosmos