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 stretched to to maintain a consistent diameter with URM-1. Upper stages 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 (currently used for the Proton-M rocket), 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 x 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 (Angara-1.2 pervyy polyot, meaning Angara-1.2 first flight), 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 Angara A5 heavy lift launch vehicle, which consists of one URM-1 core and four URM-1 boosters, a 3.6m 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 x 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.