Angara (rocket family)
The Angara rocket family is a family of launch vehicles being developed by the Moscow-based Khrunichev State Research and Production Space Center. The launch vehicles are to put between and into low Earth orbit and are intended, along with Soyuz-2 variants, to replace several existing launch vehicles.
History
After the dissolution of the Soviet Union, some formerly Soviet launch vehicles required components from companies now located in Ukraine, such as Yuzhnoye Design Bureau, which produced Zenit-2, and Yuzhmash, which produced Dnepr and Tsyklon. Additionally, the Soviet Union's main spaceport, Baikonur Cosmodrome, was located in Kazakhstan, and Russia encountered difficulties negotiating for its use. This led to the decision in 1992 to develop a new entirely Russian launch vehicle, named Angara, to replace the launch vehicles now built outside of the country, and ensure Russian access to space without Baikonur. It was decided that this vehicle should ideally use the partially completed Zenit-2 launch pad at the Russian Plesetsk Cosmodrome, and be able to launch military satellites into geosynchronous orbit, which Proton could not due to lack of a launch pad at Plesetsk Cosmodrome. Several companies submitted bids for the new launch vehicle, and in 1994 Khrunichev, the developer of Proton, was selected as the winner. The commercial success of Proton over the next two decades would be an advantage to Khrunichev, as the Angara project immediately ran into funding difficulties from the cash-strapped Russian government.Khrunichev's initial design called for the use of a modified RD-170 for first stage propulsion and a liquid hydrogen powered second stage. By 1997, the hydrogen-powered second stage had been abandoned in favor of kerosene, and the RD-170 was replaced with a modular design which would be powered by the new RD-191, a one-chamber engine derived from the four-chamber RD-170. In late 1997, Khrunichev was given approval from the Russian government to proceed with their new design, which would both be able to replace the ICBM-based Dnepr, Tsyklon, and Rokot with its smaller variants, as well as be able to launch satellites into geostationary orbit from Plesetsk with the Proton-class Angara A5.
By 2004, the design of Angara had taken shape and the project proceeded with development of the launchers. In 2008, NPO Energomash, the builder of the RD-191, reported that the engine had completed development and burn tests and was ready for manufacturing and delivery, and in January 2009 the first completed Angara first stage was delivered to Khrunichev. The next year Vladimir Nesterov, Director-General of Khrunichev, announced that the first flight test of Angara would be scheduled for 2013, and in 2013 the first prototype Angara launch vehicle arrived in Plesetsk.
In 2014, 22 years after Angara's original conception, the first launch took place on 9 July 2014, an Angara 1.2PP suborbital test flight from the northern Plesetsk Cosmodrome. On 23 December 2014, Angara A5's first test flight was performed, launching it into geosynchronous orbit. In June 2020, it was reported that the first Angara Launching Pad was completed and would be transported to Vostochny Cosmodrome.
On 14 December 2020, 6 years after the first test flight, Angara-A5's second test flight took place from Plesetsk. According to Roscosmos chief Dmitriy Rogozin speaking about future plans after the launch in December 2020, two more Angara launches were coming in 2021: an Angara-1.2 and an Angara-A5 with a new booster, Persei. Only the launch of Angara-A5 with Persei upper stage ended up happening in 2021. The maiden flight of Angara 1.2 happened on 29 April 2022.
Vehicle description
URM-1: first stage and boosters
The Universal Rocket Module forms the core of every Angara vehicle. In the Angara A5, four additional URM-1s act as boosters. Each URM-1 is powered by a single NPO Energomash RD-191 burning liquid oxygen and RP-1.The RD-191 is a single-chamber engine derived from the four-chamber RD-170, originally developed for the boosters powering the Energia launch vehicle. Zenit's four-chamber RD-171 and the dual-chamber RD-180 powering ULA's Atlas V are also derivatives of the RD-170, as is the RD-193 proposed as a replacement for the 1970s-era NK-33 powering the first stage of the Soyuz 2.1v. The RD-191 is capable of throttling down to at least 30%, allowing core URM-1 stages to conserve propellant until booster URM-1 separation.
The URM-1 consists of a liquid oxygen tank at the top, followed by an intertank structure containing flight control and telemetry equipment, with the kerosene tank below that. At the base of the module is a propulsion bay containing engine gimballing equipment for vehicle pitch and yaw and thrusters for roll control.
URM-2: second stage
The second stage of the Angara, designated URM-2, uses one KBKhA RD-0124A engine also burning liquid oxygen and kerosene. The RD-0124A is nearly identical to the RD-0124 currently powering the second stage of Soyuz-2, designated Block I. The URM-2 has a diameter of for the Angara A5 and other proposed variants. The Angara 1.2 will fly a smaller RD-0124A-powered second stage, which may be to maintain commonality with Block I or widened to to maintain a consistent diameter with URM-1.Upper stages (after 2nd)
Angara 1.2 will not use an upper stage, nor will Angara A5 when delivering payloads to low orbits. For higher energy orbits such as GTO, Angara A5 will use the Briz-M upper stage, powered by one S5.98M burning N2O4 and UDMH, or eventually a new cryogenic upper stage, the KVTK. This stage will use the LH2/LOX powered RD-0146D and allow Angara A5 to bring up to two tonnes more mass to GTO. The Blok D is being considered as an upper stage when launched from Vostochny since it will avoid the toxic propellant of the Briz-M.Variants
Angara 1.2
The smallest Angara is the Angara 1.2, which consists of one URM-1 core and a modified Block I second stage. It has a lift-off mass of 171 tonnes and can deliver 3.8 tonnes of payload to a × 60° orbit. The successful maiden launch of Angara 1.2 took place 29 April 2022.Angara 1.2pp
A modified Angara 1.2, called Angara 1.2PP, made Angara's inaugural suborbital flight on 9 July 2014. This flight lasted 22 minutes and carried a mass simulator weighing. Angara 1.2PP weighed and consisted of a URM-1 core stage and a partially fueled -diameter URM-2, allowing each of the major components of Angara A5 to be flight tested before that version's first orbital launch, conducted on 23 December 2014.Angara A5
The second Angara developed was the heavy lift launch vehicle, the Angara A5, which consists of one URM-1 core and four URM-1 boosters, a URM-2 second stage, and an upper stage, either the Briz-M or the KVTK. Weighing 773 tonnes at lift-off, Angara A5 has a payload capacity of 24.5 tonnes to a × 60° orbit. Angara A5 is able to deliver 5.4 tonnes to GTO with Briz-M, or 7.5 tonnes to the same orbit with KVTK.In the Angara A5, the four URM-1s used as boosters operate at full thrust for approximately 214 seconds, then separate. The URM-1 forming the vehicle's core is operated at full thrust for lift off, then throttled down to 30% to conserve propellant. The core is throttled back up after the boosters have separated and continues burning for another 110 seconds.
The first Angara A5 test flight was launched on 23 December 2014. The second test flight was launched on 14 December 2020 from Plesetsk. A third test flight was launched on 27 December 2021, also from Plesetsk. However, the test of Persei upper stage failed and the payload did not make it from LEO to GEO.