Russia’s Angara rocket has launched on her maiden flight from the Plesetsk Cosmodrome in Northwest Russia on Wednesday – with a T-0 of 12pm UTC – tasked with a suborbital test mission which will serve as a precursor to planned orbital launches. Angara’s first launch attempt in late June was delayed via a technical hold during the countdown, resulting in the vehicle being rolled back off the pad.
Angara, which is named after a river in Siberia, is the first new orbit-capable rocket to be developed by Russia since the fall of the Soviet Union. Designed with a modular approach, it is capable of flying in multiple configurations depending upon mission or payload requirements.
The Angara family of rockets are based around the Universalniy Raketniy Modul (URM), or Universal Rocket Module – analogous to the Common Core Boosters and Common Booster Cores of the American Atlas V and Delta IV rockets. Powered by a single RD-191M engine, the URM-1 forms the first stage of all Angara configurations.
The URM-1 consumes kerosene (paraffin) propellant, oxidised by liquid oxygen. Its RD-191 engine, built by NPO Energomash, is a single-chamber derivative of the RD-170 developed for the Zenit and Energia rockets. Although the launch marks the first flight for the RD-191, three modified engines were flown as part of the Russo-Korean Naro program.
The Naro-1 was essentially the first member of the Angara family to fly. Built by Khrunichev around a modified URM-1 with an RD-151 engine – an RD-191 with restricted thrust – the Naro-1 featured a South Korean solid-fuelled upper stage and was launched from the Korea Aerospace Research Institute’s Naro Space Centre.
The first Naro launch took place in August 2009, ending in failure when the payload fairing did not separate from the nose of the vehicle. KARI’s STSAT-2A satellite was lost in the malfunction. A second launch took place in June 2010, with STSAT-2B. On this mission the rocket exploded during first stage flight, with Russian engineers blaming the Korean-built second stage for the anomaly and Korean engineers blaming the URM.
The third and final Naro-1 launch occurred in January 2013, carrying STSAT-2C. On this occasion the rocket performed flawlessly, injecting its payload into the planned orbit. South Korea is now working on developing an indigenous rocket, the Naro-2.
Despite their modifications, the URMs flown on the three Naro launches will have provided useful data for Angara, giving Russia an opportunity to flight-test components without putting its own payloads at risk.
The Angara’s modular nature will allow it to replace many of the varied rockets which currently comprise the Russian launch fleet. At present Rokot rockets launch the majority of Russia’s small military satellites, with slightly larger satellites using the Soyuz – with the new Soyuz-2-1v configuration helping to bridge the gap in capability between these rockets.
Russia also has the Dnepr and Strela rockets available for small launches, although the former is currently used only for commercial launches while the latter is only used for the infrequent launches of Kondor optical and radar reconnaissance spacecraft.
The Kosmos-3M and Tsyklon rockets which served this payload class for many years were retired from service in 2012 and 2009 respectively, while the little-used Start-1, Volna and Shtil’ have not been used for some time and no longer seem to be in service.
The Soyuz and Proton rockets bear the brunt of Russia’s launch activity. A descendent of Korolev’s original R-7 missile – which first flew in 1957 and was modified to launch Sputnik 1 later that year, three types of Soyuz are currently in service.
The Soyuz-U, which is being phased out, is the single most-launched rocket in the history of orbital spaceflight with over 750 missions under its belt. This rocket is now only used to deploy Progress spacecraft for missions to the International Space Station.
The Soyuz-FG was introduced in 2001 to provide the updates necessary to carry manned Soyuz-TMA spacecraft and is used almost exclusively for manned launches. The current-generation Soyuz-2 is a modernised rocket, with uprated engines, digital flight controls and in the case of the Soyuz-2-1b a more powerful second stage engine.
While the Soyuz-2 is expected to replace the Soyuz-U in the short term and the Soyuz-FG in the long term, the Soyuz is the only rocket in regular use by the Russian government which is not being considered for replacement with the new Angara-1.
By contrast, Russia’s other workhorse, the Proton-M, is likely to be among the first to be replaced. The largest and most powerful rocket in the fleet, Proton is used for Geostationary launches and multi-satellite missions in support of Russia’s GLONASS navigation system. A string of recent high-profile failures, including an attempt last July where the vehicle went out of control within seconds of liftoff, have combined with concerns over the toxicity of its propellants to hasten calls for its retirement.
Proton was developed in the 1960s, as part of Vladimir Chelomei’s Universal Rocket series – a failed attempt of its day to consolidate the Soviet launch fleet into a smaller number of similarly designed rockets.
In this respect Proton is a distant cousin of the Rokot and Strela, which were derived from the smallest Member of the Universal Rocket family – the UR-100.
The final active member of Russia’s launch fleet is the Zenit. Out of favour since the end of the Soviet Union left it’s manufacture in Ukraine, the Zenit is mostly used for commercial payloads both in launches from Baikonur and from the Odyssey platform at the equator as part of the Sea Launch project.
The rocket is occasionally used to launch spacecraft for Roskosmos, but has not made a military launch since 2007.
The Angara-1 is the smallest member of the Angara family, intended to replace the Rokot and the other small rockets. Two different versions of the Angara-1 are available; the Angara-1.1 consists of a single URM-1, topped by a Briz-KM upper stage. Hypergolically fuelled, the Briz-KM has been used as the third stage of the Rokot since 2000 and also forms the core of the Briz-M upper stage used by the Proton.
For missions requiring slightly greater performance, the Angara-1.2 replaces the Briz with a new stage derived from the Soyuz-2-1b’s Blok-I third stage and powered by an RD-0124A engine. The Blok-I itself was introduced in 1960 as part of the Molniya rocket; later being used on the Voskhod and then the Soyuz.
The next step up is the Angara-3, or Angara-A3, which adds two extra URM-1s burning in parallel with the core. Under Russian nomenclature these will likely be termed the first stage, with the core stage being designated stage 2. The third stage, in place of the modified Blok-I used on the Angara-1.2, will be a URM-2.
The URM-2 is a widebody stage with an RD-0124A engine. The RD-0124A is a variant of the RD-0124 used on Soyuz, but recertified for the longer burns which will be required with the larger URM-2 stage. A payload fairing developed for the Proton will complete the A3 configuration.
For launches requiring higher orbits, a fourth stage can be added to the A3; either a standard Briz-M or the cryogenically-fuelled KVSK.
The Angara-5, or A5, is seen as a replacement for the Proton. With four strapon URM-1s clustered around the core stage, the A5’s configuration is otherwise the same as the A3. In terms of upper stage selection the Briz-M remains available, with the KVTK offered instead of the KVSK.
Both the KVSK and KVTK are new stages which harness cryogenic propellants; liquid hydrogen and liquid oxygen. When built, they will make the Angara the first Russian or Soviet rocket to fly with a fully-cryogenic stage since the Energia in the 1980s.
Both stages are powered by RD-0146D restartable LPREs, which build on experience Russia has gained from the KVD-1 engines it built for India’s Geosynchronous Satellite Launch Vehicle Mk.I.
The KVSK is smaller and less powerful than the KVTK, reducing the performance hit in the early stages of flight as it launches on the less powerful A3. A similarly-engined KVRB stage has been suggested as a replacement for the URM-2 on A5 launches requiring extra performance.
An additional variant, the Angara-7 or A7, has been proposed. It would see seven URM-1s clustered to launch the largest payloads. Nothing has come of this proposal, which would have produced a rocket with greater payload capacity than anything currently in service.
The launch utilized a unique configuration, the Angara-1.2PP (the PP being an abbreviation of первый полет or “pervyy polyot” meaning “first flight”). This consists of a URM-1 topped by a URM-2, with no additional strapons and no upper stage. This allows both URM stages to be tested in a single flight.
The launch also marked the first use of Site 35/1 at the Plesetsk Cosmodrome. Site 35 was originally to have been the primary launch complex for the Zenit rocket, but by the time construction began in 1986 most launches had been moved to the Baikonur Cosmodrome. After the collapse of the Soviet Union the Russian government looked to reduce its reliance on the now-Ukrainian Zenit and as a result the Plesetsk launch complex was never completed.
Future Angara launches will take place from Plesetsk and the new Vostochny Cosmodrome in Eastern Russia. A launch complex at Baikonur, on the site of the former Energia launch pad at Site 250, was under development, however the project has repeatedly stalled due to political problems.
The suborbital test ended with an impact at the Kura test range in East Russia. A common destination for missile tests, using the range for the Angara launch allows for safe disposal of the second stage and provides Russia with the ability to track the launch along most of its path using its existing tracking network.
The successful launch for the Angara-1.2PP will pave the way for the Angara’s first orbital launch. This mission, which will use the Angara-A5 with a Briz-M upper stage and carry a mass simulator, is currently scheduled for the end of the year.
(Images via L2’s Angara Section and Roscosmos).