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Angara-5's flight scenario
During its first test launches, Angara-A5 was expected to demonstrate its ability to deliver cargo into geostationary orbit 36,000 kilometers above the Equator, the destination for most communications satellites. However, two initial missions in 2014 and 2020 only carried a payload simulator, rather than an operational spacecraft. After reaching its target, the 2,042-kilogram dummy satellite, GVM (a.k.a. GMM or NVP PM), was to be boosted into a safe "burial" orbit, away from heavy traffic at the geostationary altitude.
The Angara-A5 rocket configured for the first launch.
Flight program for test launches In order to reach an equatorial orbit from Plesetsk, Angara-A5 needs to enter an initial orbit with the lowest inclination accessible from that high-latitude launch site. Flying eastward from Plesetsk results in the tilt of the orbit at around 63 degrees toward the Equator. In the subsequent maneuvers, the Briz-M upper stage, transfers its cargo to a geostationary altitude and tilts the orbital inclination to match the equatorial plane. The Angara-5 rockets are equipped with four URM-1 boosters, acting as the first stage, and a single "core" URM-1, performing the role of the second stage. All five URM-1s ignite on the ground, however the core module operates at lower thrust during the middle part of the flight. As a result, the four first-stage boosters consume their propellant and separate first, while the core URM-1 booster can continue to fire. According to a known flight profile, after 47 seconds of ascent at full thrust, the RD-191 engine on the central booster throttles down to 30 percent of its thrust capability. The four boosters of the first stage separate 3 minutes and 29 seconds into the flight at an altitude of around 86 kilometers and a speed exceeding 3 kilometers per second. The empty boosters then impact the ground 869 kilometers from the launch site at the Vuktyl Range in the Sosnogorsk Region of Komi Republic. In the meantime, the core stage returns to full thrust and fires for a total of 5 minutes and 26 seconds. It separates from the third stage at an altitude of 160 kilometers with the help of small solid motors installed "backwards" at the very top of the rocket's transfer compartment. At that point, the vehicle reaches a velocity of 4.8 kilometers per second. The empty stage then crashes in the Tomsk Region, around 2,300 kilometers from the launch pad. The epicenter of the impact site for the second stage is located at the Kolpashevo Range in the Kargasok District of the Tomsk Region, 70 kilometers southeast of the border with the Parabelsk District. Just two seconds after the separation of the core stage, the URM-2 ignites its RD-0124 engine to accelerate the payload section to a nearly orbital speed and 14 seconds later, the payload fairing protecting the payload splits into two halves and falls off. In a typical mission, the URM-2 fires until T+733 seconds (12 minutes and 13 seconds) in flight and separates two seconds later. At that point, the vehicle is 215 kilometers above the Earth, flying with a speed of more than 7.1 kilometers per second. The third stage then reenters the atmosphere and splashes down in the Pacific Ocean, off the coast of Philippines, 8,266 kilometers from the launch site.
The flight profile and a ground track of the Angara-5 launches from Plesetsk. The Briz-M (fourth) stage completes the orbital insertion process with a short firing of its engine to enter an initial parking orbit with an altitude ranging from 180 to 250 kilometers. In the first Angara-5 mission, this job will be performed by the Briz-M upper stage, previously employed on the Proton rocket. As a result, the subsequent flight scenario will likely resemble that of a typical Proton mission to the geostationary orbit. During a nine-hour period, the Briz-M usually conducts five engine firings to enter an initial parking orbit and then to climb to a geostationary transfer orbit with its apogee (highest point) at an altitude of around 36,000 kilometers. The final maneuver is also used to do most of the orbital inclination adjustment to match the plane of the Equator. Given the fact that Russian satellites are traditionally delivered directly into geostationary orbit rather than being dropped at an intermediate orbit like it is usually the case with many Western satellites, Briz-M will likely make another maneuver at the apogee of the elliptical geostationary transfer orbit to make it circular at an altitude of around 36,000 kilometers. After the separation from its payload, Briz-M usually maneuvers itself into a "burial" orbit, where its tanks are depressurized to avoid an accidental explosion producing space junk. During Angara-5's test flight, Briz-M can take its dummy cargo with it, instead of releasing it into the busy geostationary orbit. The launches of Angara-5 rockets are supported by six ground stations along the flight path of the rocket in Plesetsk, Naryan-Mar, Vorkuta, Yeniseysk, Barnaul and Ulan-Ude. It is known that the ground station in Plesetsk can track the rocket as late as 448 seconds in flight and Naryan Mar will join in at T+215 seconds and continue seeing it until T+543 seconds. The ground station in Vorkuta will first "see" the rocket at T+326 seconds and have it within the communications range until T+618 seconds. Angara-5 might need new place to crash its boosters On September 10, 2014, a poster on the online forum of the Novosti Kosmonavtiki magazine reported that a recent trip of a survey team to the locations where URM-1 boosters were to be dropped during the first launch of the Angara-5 rocket, deemed them unacceptable for the mission. The group discovered that an extremely dense forest at those sites would make it impossible to recover the remnants of the boosters.
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