The Soyuz-2.1v (Russian: Союз 2.1в, Union 2.1v), GRAU index 14A15,^[1] known earlier in development as the Soyuz-1 (Russian: Союз 1, Union 1), is a Russian expendable launch vehicle. It is a heavily modified derivative of the Soyuz-2.1b, and is a member of the R-7 family of rockets. It is built by TsSKB Progress, at Samara in Russia. Launches are conducted from existing facilities at the Plesetsk Cosmodrome in Northwest Russia, with pads also available at the Baikonur Cosmodrome in Kazakhstan,^[2] and new facilities at the Vostochny Cosmodrome in Eastern Russia.^[3]

The Soyuz-2.1v represents a major departure from earlier Soyuz rockets. Unlike the Soyuz-2.1b upon which it is based, it does away with the four boosters used on all other R-7 vehicles. The first stage of the Soyuz-2.1v is based on the Soyuz-2 second stage, with a single-chamber NK-33 engine replacing the four-chamber RD-108 along with structural modifications. Since the NK-33 is fixed, the stage is also equipped with an RD-0110R engine for thrust vector control. The RD-0110R also adds 230.5 kN (51,800 lb_f) thrust and heats the pressurization gases.^[4]

The NK-33 engine, originally built for the N1 programme, offers increased performance over the RD-107; however, only a limited number of engines are available. Once the supply is exhausted, the NK-33 will be replaced by the RD-193. In April 2013, it was announced that the RD-193 engine had completed testing. The RD-193 is a lighter and shorter engine based on the Angara's RD-191, which is itself a derivative of the Zenit's RD-170.^[5]

The second stage of the Soyuz-2.1v is the same as the third stage of the Soyuz-2.1b;^[6] powered by an RD-0124 engine. Most missions will use a Volga upper stage to transfer the payload from an initial parking orbit to its final destination. The Volga is derived from the propulsion system of the Yantar reconnaissance satellite, and was developed as a lighter and cheaper alternative to the Fregat.

The Soyuz-2.1v was designed as a light-class carrier rocket, and has a payload capacity of 2,850 kg (6,280 lb) to a 200 km (120 mi) circular low Earth orbit with an inclination of 51.8° from Baikonur, and 2,800 kg (6,200 lb) to a 200 kilometre orbit at 62.8° from Plesetsk.^[2][7]

• General view of the rocket
• Second stage view
• Detailed view of the payload section

Russia exhibited a model of the Soyuz-2.1v during the 2011 Paris Air Show at Le Bourget.

• List of R-7 launches