The URM-2 rocket module for the Angara family

The second stage of the Angara launch vehicle is known as URM-2, which stands for Universal (or common) Rocket Module No. 2.


Cutaway view of the URM-2 rocket stage configured for the first launch of the Angara rocket. Copyright © 2014 Anatoly Zak

From the publisher: Please help to keep this site open and current! The pace of our development depends primarily on the level of support from our readers.


Angara owes its unusual appearance to the URM-2 upper stage whose diameter of 3.6 meters makes it wider than the 2.9-meter first-stage booster below it. Like the first stage, the URM-2 uses liquid oxygen oxidizer and kerosene fuel. However, on the URM-2, the kerosene tank is installed in the upper position, with the liquid oxygen tank below it. The stage is powered by the four-chamber RD-0124A engine, adapted from the third stage of the Soyuz-2 rocket.

The aft bulkhead of the oxidizer tank also carries spherical vessels containing pressurization gas. Front bulkheads have access hatches and drainage valves. Because oxidizer tank contains cryogenic liquid oxygen, both of its bulkheads are covered with thermal blankets to reduce heating.

All electric connections, fueling and thermal conditioning of the URM-2 stage on the launch pad is accomplished via quick-disconnect umbilicals, BRS, of the stationary service tower.

In the course of development, there was also an alternative proposal to use a pair of one-chamber RD-0125A engines with a total thrust of 59 tons on URM-2. The new engine would lower the cost of the stage and increase its payload, but it had never been developed.

According to the original plans, the URM-2 stage was supposed to be used on both types of the Angara launch vehicles approved for development -- the Angara-1 and the Angara-5. Ultimately, the decision was made to develop a custom-built upper stage for the Angara-1 and use the URM-2 on the Angara-5 only. (The Angara-3, if ever built, could also use URM-2.) Still, during the first inaugural launch of the new rocket family, the URM-2 stage flew as the second stage of the first Angara-1 rocket. It was not intended to reach orbit, but was programmed to fire its RD-0124A engine, testing flight performance of the entire stage. As a result, by the time the Angara-5 rocket is ready to fly, the flight-tested URM-2 would be ready to serve as the third stage.

Still, a live firing of a fully integrated URM-2 stage was planned at the RKTs test center as late as 2019.


A fully assembed URM-2 stage of the Angara-NZh full-scale prototype (INSIDER CONTENT) during processing in Vostochny in October 2023.


Known specifications of the URM-2 module:

3.6 meters
6.9 meters
Propulsion system
Luquid oxygen


URM-2 mass specifications:

Liftoff mass
*39,746 kilograms
Propellant mass
35,222 kilograms
Dry mass
*4,800 kilograms
Dry mass of the stage core structure
3,700 kilograms
Dry mass of the transfer adapter
900 kilograms

*includes the 100-kilogram lower transfer ring.


Page author: Anatoly Zak; Last update: October 28, 2023

Page editor: Alain Chabot; Last edit: June 16, 2014

All rights reserved


insider content



A prototype of Angara's upper stage known as the A5A2S article No. A13 is being towed to a test stand at the Remmash facility at the NITs RKP test center in Peresvet for endurance tests in cryogenic environment in the fall of 2012. Credit: GKNPTs Khrunichev


Tanks for the URM-2 booster during production in Omsk. Credit: PO Polyot



Assembly of the URM-2 rocket module for the Angara-5 rocket. Its fuel tank can be seen on the background on the left. Credit: GKNPTs Khrunichev


Propulsion system and oxidizer tank of the URM-2 stage.


A prototype of the URM-2 module for the Angara-1.2PP rocket in Plesetsk in July 2012. Credit: Zvezda TV channel


Final processing of the URM-2 booster for the Angara-1.2PP rocket in Plesetsk. Credit: Rossiya TV channel