Proton (rocket family)

Proton (rocket family)
Name	Proton
Caption	A Proton-K launching the Zarya module for the International Space Station in 1998.
Function	Expendable medium and heavy-lift launch vehicle
Manufacturer	Khrunichev State Research and Production Space Center
Country origin	Soviet Union / Russia
Height	53, –, 58.2, m, ft
Diameter	7.4, m, ft
Mass	693,810, kg, lb
Stages	3 or 4
Capacity LEO	23,700, kg, lb
Capacity GTO	6,920, kg, lb
Status	Retired (Proton-K, Proton-M active but being phased out)
Launches	428 (as of July 2024)
Success	383
Fail	45
First	Proton 1 (Kosmos-60), 16 July 1965
Last	Planned final flight in 2025

Proton (rocket family) is a family of Russian heavy-lift launch vehicles that originated in the Soviet Union. Developed by the OKB-52 design bureau under Vladimir Chelomey, it became a workhorse for launching large satellites, space station modules, and interplanetary probes. Operated from Baikonur Cosmodrome, its various versions have conducted hundreds of missions for both government and commercial clients since the mid-1960s.

Overview

The Proton rocket is a cornerstone of Soviet and Russian space logistics, primarily launched from Site 81 and Site 200 at the Baikonur Cosmodrome in Kazakhstan. Managed initially by the Soviet space program and later by Roscosmos, its operational control was handled by the Russian Aerospace Forces. The rocket's primary contractor and manufacturer has historically been the Khrunichev State Research and Production Space Center in Moscow. For decades, it served as the principal vehicle for launching elements of the Salyut and Mir space stations, critical modules for the International Space Station, and a vast array of GLONASS navigation satellites and commercial communications satellites.

Development history

The Proton's origins lie in the Cold War era, conceived by Vladimir Chelomey's OKB-52 as a super-heavy ICBM and as a launch vehicle for the UR-500 designation. The Soviet government, under Nikita Khrushchev, authorized its development as a counter to American programs like the Saturn I. Its first test flight in 1965 carried the Proton 1 scientific satellite. The design was subsequently adapted for space launch, with major evolution occurring under the oversight of the Ministry of General Machine Building. The program survived the transition from the Soviet Union to the Russian Federation, with continued upgrades leading to the Proton-M variant in 2001.

Design and variants

The standard Proton is a three-stage rocket using storable, hypergolic propellants like dinitrogen tetroxide and unsymmetrical dimethylhydrazine. The first stage consists of a central oxidizer tank surrounded by six outboard fuel tanks, each with a RD-275 engine. The second stage uses four RD-0210 engines, and the third stage employs a single RD-0212 engine. Major variants include the original three-stage Proton-K, which flew from 1967 to 2012, and the modernized Proton-M with a digital control system and an optional Briz-M upper stage for high-energy orbits. A commercial version, marketed by International Launch Services, often utilized the Briz-M or the older Block DM upper stage.

Launch history and operational use

Since its maiden flight in 1965, the Proton family has conducted over 425 launches, establishing an extensive operational record through the late 20th and early 21st centuries. Its launches were integral to the Soviet space program, supporting the Luna, Venera, and Mars planetary missions. The rocket was the exclusive launcher for all Salyut stations and core modules of the Mir station. Following the dissolution of the Soviet Union, it became a major player in the global commercial launch market, with missions procured by companies like ILS and Eutelsat. Operations are being phased out in favor of the Angara rocket family.

Notable payloads and missions

The Proton has launched many historic payloads, including the first Soviet space stations, Salyut 1 and the core module of Mir. It deployed the Zarya and Zvezda modules, which are fundamental to the International Space Station. Significant interplanetary missions launched by Proton include the Venera 9 lander, the Vega probes to Halley's Comet, and the ExoMars Trace Gas Orbiter. It also orbited major communication satellites like Arabsat and AsiaSat, as well as the entire constellation of GLONASS navigation satellites.

Accidents and failures

The Proton has experienced several high-profile failures, often attributed to quality control issues in its manufacturing supply chain. A 2013 crash shortly after launch from Baikonur Cosmodrome resulted in the loss of three GLONASS satellites and significant environmental contamination due to its toxic propellants. Other notable failures include a 1999 incident that destroyed a Raduga satellite, a 2014 anomaly during a Roscosmos mission, and a 2015 failure that lost a Mexican Satmex satellite. These incidents led to grounding, investigations by state commissions, and temporary suspensions of commercial flights.

Category:Proton (rocket family) Category:Expendable launch systems Category:Soviet and Russian launch vehicles