Encyclopedia Astronautica
UR-500MK


Russian orbital launch vehicle. In 1975 Chelomei proposed this version of the Proton powered by lox/kerosene NK-33 engines developed for the cancelled N1 moon booster. This would give the Soviet Union an equivalent to the all-new Zenit-2 booster being developed by Glushko, but at a fraction of the time and expense through the use of existing components. The proposal had no chance politically, and was never seriously considered.

In response to the Ministry of Defense's guidelines for third generation launch vehicles, the Ministry of General Machine Building issued on 29 April 1975 instructions for Chelomei to study boosters meeting the military's requirements. These included Lox/Kerosene propellants in place of the toxic N2O4/UDMH favored previously. Chelomei's competitor in the design, Glushko, was then head of NPO Energia which included Glushko's former OKB-456 engine design bureau. Therefore Chelomei was forced to propose using Kuznetsov Lox/Kerosene engines from the cancelled N1 moon program.

The UR-500MK was proposed in two configurations, the 11K98 and 11K99. In keeping with the mandated modular approach, the UR-500MK consisted of a core stage with a single modified NK-43 engine with a vacuum thrust of 190 metric tons. This was boosted by three (11K98) or six (11K99) lateral stages, each with a single modified NK-33 engine of 150 metric tons thrust. All engines ignited at lift-off, throttled to over 100% of their rated thrust. The core engine was apparently fed from the lateral stages or throttled back early in the ascent to conserve propellant for the second stage burn. The use of existing Proton tankage tooling for the stages and the Kuznetsov engines would allow a high-performance vehicle to be developed at minimum cost. However Chelomei was out of favor, Kuznetsov was discredited after the N1 fiasco, and Glushko was ascendant. The proposal stood no chance. Glushko's Zenit launch vehicle became the accepted solution.

The two variants had the following characteristics:

  • 11K99 (six lateral stages):
    • Launch mass: 1000 t
    • Dry mass: 68 t
    • Propellant mass : 915 t (Kerosene : 250 t - Lox : 665 t)
    • Payload to 200 km, 51.6 deg orbit: 30 - 31.5 metric tons
    • Payload to 200 km, 97deg sun-synchronous orbit: 25.5 - 26.8 metric tons
    • Payload to geostationary orbit:
      • with Lox/Kerosene upper stage: 3.5 metric tons
      • with Lox/LH2 upper stage: 5.2 metric tons
  • 11K98 (three lateral stages):
    • Launch mass: 590 t
    • Payload to 200 km, 51.6 deg orbit: up to 15 metric tons
    • Payload to 200 km, 97deg sun-synchronous orbit: 11 - 12.5 metric tons

LEO Payload: 30,000 kg (66,000 lb) to a 200 km orbit at 51.60 degrees. Payload: 3,500 kg (7,700 lb) to a GEO.

Stage Data - UR-500MK

  • Stage 1. 6 x UR-500MK-1. Gross Mass: 137,000 kg (302,000 lb). Empty Mass: 9,300 kg (20,500 lb). Thrust (vac): 1,637.000 kN (368,012 lbf). Isp: 331 sec. Burn time: 250 sec. Diameter: 4.15 m (13.61 ft). Span: 4.15 m (13.61 ft). Length: 20.00 m (65.00 ft). Propellants: Lox/Kerosene. No Engines: 1. Engine: NK-33. Status: Study 1975. Comments: Empty mass estimated based on overall vehicle mass fraction. Length estimated based on total mass.
  • Stage 2. 1 x UR-500MK-2. Gross Mass: 161,000 kg (354,000 lb). Empty Mass: 11,000 kg (24,000 lb). Thrust (vac): 1,860.000 kN (418,140 lbf). Isp: 346 sec. Burn time: 270 sec. Isp(sl): 246 sec. Diameter: 4.15 m (13.61 ft). Span: 4.15 m (13.61 ft). Length: 20.00 m (65.00 ft). Propellants: Lox/Kerosene. No Engines: 1. Engine: NK-43. Status: Study 1975. Comments: Empty mass estimated based on overall vehicle mass fraction. Length estimated based on total mass.

Status: Design 1975.
Gross mass: 1,000,000 kg (2,200,000 lb).
Payload: 30,000 kg (66,000 lb).
Height: 62.54 m (205.18 ft).
Diameter: 4.15 m (13.61 ft).
Span: 7.40 m (24.20 ft).
Thrust: 11,300.00 kN (2,540,300 lbf).
Apogee: 200 km (120 mi).

More... - Chronology...


Associated Countries
See also
  • Proton The Proton launch vehicle has been the medium-lift workhorse of the Soviet and Russian space programs for over forty years. Although constantly criticized within Russia for its use of toxic and ecologically-damaging storable liquid propellants, it has out-lasted all challengers, and no replacement is in sight. More...

Associated Manufacturers and Agencies
  • Chelomei Russian manufacturer of rockets, spacecraft, and rocket engines. Chelomei Design Bureau, Reutov, Russia. More...

Associated Stages
  • UR-500MK-2 Lox/Kerosene propellant rocket stage. Loaded/empty mass 161,000/11,000 kg. Thrust 1,860.00 kN. Vacuum specific impulse 346 seconds. Empty mass estimated based on overall vehicle mass fraction. Length estimated based on total mass. More...
  • UR-500MK-1 Lox/Kerosene propellant rocket stage. Loaded/empty mass 137,000/9,300 kg. Thrust 1,637.00 kN. Vacuum specific impulse 331 seconds. Empty mass estimated based on overall vehicle mass fraction. Length estimated based on total mass. More...

UR-500MK Chronology


1975 April 29 - . LV Family: Proton. Launch Vehicle: UR-500MK.
  • UR-500MK designed - . Nation: USSR. Related Persons: Chelomei; Glushko. In response to the Ministry of Defence's guidelines for third generation launch vehicles, the Ministry of General Machine Building issued instructions for Chelomei to study boosters meeting the military's requirements. These included Lox/Kerosene propellants in place of the toxic N2O4/UDMH favoured previously. Chelomei's competitor in the design, Glushko, was then head of NPO Energia which included Glushko's former OKB-456 engine design bureau. Therefore Chelomei was forced to propose using Kuznetsov Lox/Kerosene engines from the cancelled N1 moon program. The use of existing Proton tankage tooling for the stages and the Kuznetsov engines would allow a high-performance vehicle to be developed at minimum cost. However Chelomei was out of favour, Kuznetsov was discredited after the N1 fiasco, and Glushko was ascendant. The proposal stood no chance. Glushko's Zenit launch vehicle became the accepted solution.

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