Proton Breeze M

Proton 8K82K

Launch of a Proton-K rocket
Function	Orbital launch vehicle
Manufacturer	Khrunichev State Research and Production Space Center
Country of origin	Soviet Union; Russia
Size
Height	53 metres (174 ft)
Diameter	7.4 metres (24 ft)
Mass	693.81 metric tons (1,529,600 lb) (3 stage)
Stages	3 or 4
Capacity
Payload to LEO	22.8 metric tons (50,000 lb)
Payload to GTO	6.3 metric tons (14,000 lb)
Launch history
Status	Active
Launch sites	Baikonur, LC-200 & LC-81
Total launches	414 M: 102 K: 311 Proton: 4
Successes	367 M: 92 K: 275 Proton: 3
Failures	34 M: 9 K: 24 Proton: 1
Partial failures	13 M: 1 K: 12
First flight	Proton: 16 July 1965 Proton-K: 10 March 1967 Proton-M: 7 April 2001
Last flight	Proton: 6 July 1966 Proton-K: 30 March 2012 Proton-M: 11 September 2017
Notable payloads	Salyut 6 Salyut 7 Mir ISS components ViaSat-1
First stage
Engines	6 RD-275
Thrust	10.47 MN (1.9 million pounds)
Burn time	126 s
Fuel	N2O4/UDMH
Second stage
Engines	3 RD-0210 & 1 RD-0211
Thrust	2.399 MN (539,000 lbf)
Specific impulse	327 s
Burn time	208 s
Fuel	N2O4/UDMH
Third stage
Engines	1 RD-0212
Thrust	630 kN (140,000 lbf)
Specific impulse	325 s
Burn time	238 s
Fuel	N2O4/UDMH
Fourth stage - Blok-D/DM
Engines	RD-58M
Thrust	83.4 kN (18,700 lbf)
Specific impulse	349 s
Burn time	770 s
Fuel	LOX/RP-1

Proton (Russian: Протон) (formal designation: UR-500) is an expendable launch system used for both commercial and Russian government space launches. The first Proton rocket was launched in 1965. Modern versions of the launch system are still in use as of 2017, making it one of the most successful heavy boosters in the history of spaceflight. All Protons are built at the Khrunichev State Research and Production Space Center plant in Moscow, transported to the Baikonur Cosmodrome, brought to the launch pad horizontally, and raised into vertical position for launch.

As with many Soviet rockets, the names of recurring payloads became associated with the Proton. The moniker "Proton" originates from a series of similarly named scientific satellites, which were among the rocket's first payloads. During the Cold War, it was designated the D-1/D-1e or SL-12/SL-13 by Western intelligence agencies.

Launch capacity to low Earth orbit is about 22.8 tonnes (50,000 lb). Geostationary transfer capacity is about 6.3 tonnes (14,000 lb).Commercial launches are marketed by International Launch Services (ILS). The rocket is intended to be retired before 2030.

In January 2017, the Proton was temporarily grounded due to the manufacturer, Voronezh Mechanical Plant, having substituted a heat-resistant alloy in the engines with a cheaper metal.

Proton initially started its life as a "super heavy ICBM". It was designed to launch a 100-megaton (or larger) thermonuclear weapon over a distance of 13,000 km. It was hugely oversized for an ICBM and was never deployed in such a capacity. It was eventually used as a space launch vehicle. It was the brainchild of Vladimir Chelomei's design bureau as a foil to Sergei Korolev's N1 rocket, whose purpose was to send a two-man Zond spacecraft around the Moon; Korolev openly opposed Proton and Chelomei's other designs for their use of toxic propellants.