Proton-M/Block DM-03 – Launch Vehicle
The Proton Rocket Family is one of the most successful heavy-lift boosters in the history of space flight. Being designated UR-500, the Rocket started out as a Super Intercontinental Ballistic Missile in the 1960’s. As it was capable of launching a 100-megaton nuclear warhead, Proton was hugely over-sized and became a Space Launcher designed to lift the heaviest payloads to space.
The first Proton Launch was made in 1965. during the first five years of operation, the system experienced dozens of failures before becoming a reliable booster. Over the years, the Proton Family underwent several modifications and re-designs in order to keep the Rocket’s System up to date using modern technology. The early version of the Proton Family was called 8K82 and was equipped with only two stages. Proton-K was the first featuring three stages and an optional upper stage. The Proton-K Launcher was retired in 2012, leaving only the improved version of the Family, Proton-M, active.
This particular launcher configuration made its first launch in 2001. Proton-M is also a three-stage rocket with the capability to support a upper stage. Block D/DM and Briz-M (English: Breeze-M) Upper Stages are used on top of the Proton to enable the heavy-lift vehicle to deliver its payload to a variety of orbits and trajectories. The Proton Rocket is launched from Sites 81 and 200 of the Baikonur Cosmodrome, Kazakhstan. Khrunichev State Research and Production Space Center is the manufacturer of Proton-M Briz-M. Proton-M Launchers are operated by the Russian Government for official government mission. Also, the Rocket has been made available for commercial launches which are being operated by International Launch Services.
The Proton Family has more than 340 Launches under its belt keeping a success rate of nearly 90%. Notable payloads included modules of the Russian Salyut and Mir Space Stations as well as the Zarya and Zvezda Modules of the International Space Station. Many commercial communication satellites have been orbited using Proton-M Rockets with Briz-M Upper Stages.
Proton-M/Block DM-03 Specifications
|Stages||3 (+ Optional Upper Stage)|
|Mass to LEO||22,000kg|
|Mass to GTO – Briz-M||6,000kg|
|Mass to GSO – Briz-M||3,500kg|
The Proton-M Vehicle consists of three Stages each equipped with different engines that place the orbital Unit Consisting of Upper Stage and Payload to its desired trajectory in about 9 minutes. Compared to previous Proton versions, Proton-M utilizes light-weight technology as part of an effort to reduce launcher mass to maximize its capability. Also, the avionics of the Proton-M are digital, state of the art systems. Proton-M uses a simple design philosophy to increase reliability and improve flight heritage on proven components.
Overall, Proton-M/Block DM-03 stands 58.2 meters tall with a diameter of 7.4 meters and a launch mass of nearly 713,000 Kilograms. Proton-M can deliver payloads of up to 22,000 Kilograms to Low Earth Orbit. With Block DM-03, the Proton can deliver satellites of 6 metric tons into Geostationary Transfer Orbit. Direct Geosynchronous injection capability is 3.5 tons.
|Type||Storable Propellant Stage|
|Guidance||From third Stage|
|Propulsion||6 x RD-275M|
|RD-275M Thrust SL||1,657kN|
|RD-275M Thrust Vac||1,833kN|
|Total SL Thrust||9,942kN|
|Total Vac Thrust||10,998kN|
|Engine Dry Weight||1,080kg|
|Ox. To Fuel Ratio||2.67|
The first and largest stage of the Proton-M Rocket has an inert mass of 31,000 Kilograms. It consists of the central tank containing the Oxidizer, Nitrogen Tetroxide. This large central tank is surrounded by six outboard propellant tanks containing Unsymmetrical Dimethylhydrazine which is used as fuel. The outboard tanks give the impression of strap-on rocket boosters, but are not separated during flight.
Each of the fuel tanks has a modified RD-253 Engine installed on it. Those engines are known as RD-275M or RD-276. Since 1965, the first stage engines have only been modified slightly, increasing performance to 112% of initial performance. The RD-275M operates at a higher chamber pressure as improved manufacturing techniques are available. The RD-275M uses a staged combustion cycle with oxidizer-rich generator gas.
RD-275M provides a sea level thrust of 1,657 Kilonewtons – giving the Proton a liftoff thrust of 9,942 Kilonewtons – 1.014 Million Kilograms creating an initial thrust-to-weight ratio of 1.42. The engine operates at a chamber pressure of 16.9MPa with an expansion ratio of 241. Overall, the engine is 2.72 meters long, 1.5m in diameter with a dry mass of 1,080kg and a filled mass of 1,260kg. RD-253/275 has a reliability coefficient of .998.
Proton uses a one-degree of freedom thrust vector control system on its first stage. Each of the six engines can only move +/-7 degrees in one direction, tangentially to the circular engine cluster.
The first stage is separated from the launch vehicle after 120 seconds into the mission. Modifications allowed reduced propellant residuals in the Proton’s stages in order to improve launcher performance and avoid environmental hazards as the Propellants are highly toxic. Guidance data is provided by the Navigation System that is installed on the third stage.
|Type||Storable Propellant Stage|
|Guidance||From third Stage|
|Propulsion||3 x RD-0210 & 1 x RD-0211|
|Engine Dry Weight||566kg|
|Chamber Pressure||14.7 MPa|
|Tank Pressurization||Via RD-0211|
Unlike the first stage, the second stage of the Proton-M uses the conventional cylindrical stage design with Fuel and Oxidizer Tanks mounted in a stacked manner.
The second stage also uses Nitrogen Tetroxide and Unsymmetrical Dimethylhydrazine as propellants.
With an empty weight of 11,700 Kilograms, the stage holds up to 156,100 Kilograms of propellants that are used during 206 seconds of powered flight before the stage is separated from the third stage of the vehicle.
Stage is powered by four engines, three RD-0210 engines and one RD-0211 engine which is a slightly modified RD-0210 engine that accommodates a gas generator heat exchanger that supplies pressurant gas to the propellant tanks to keep them at proper flight pressure levels.
In total, all engines provide approximately 2.4 Meganewtons of thrust – 244,600 Kilograms. The RD-0210 engine is also a staged combustion cycle engine. Each of the four engines is 2.33 meters long, 1.47 meters in diameter and weighs 566 Kilograms operating at a chamber pressure of 14.7 MPa.
|Type||Storable Propellant Stage|
|Propulsion||RD-0213 Engine + RD-0214 Vernier|
|RD-0213 Thrust Vac||583kN|
|Chamber Pressure||14.7 MPa|
|Chamber Pressure||5.3 MPa|
The third stage of the Proton-M Rocket is the final stage of the actual launch vehicle that delivers the orbital unit to a preliminary orbit or a suborbital trajectory, depending on the mission profile.
This stage also utilizes a conventional design and consumes Nitrogen Tetroxide and Unsymmetrical Dimethylhydrazine a propellants. An RD-0213 engine powers the vehicle providing 583 Kilonewtons of thrust.
This engine is a non-gimbaled version of the RD-0210 engine that is used on the second stage. For vehicle control and additional thrust, an RD-0214 Engine with four gimbaled nozzles is installed on the third stage.
The RD-0214 provides 31 Kilonewtons of thrust for a total 3rd stage thrust 62,600 Kilograms.
The third stage houses the vehicle’s Navigation, Guidance and Control System that operated the vehicle during all aspects of powered flight which is fully automated and does not require commands from ground stations. A triple redundant digital guidance system is used to control the vehicle.
The Control System has been upgraded several times since the Proton-M started operations in 2001. The guidance mode used is cosed-loop. A high-precision three-axis gyro stabilizer provides exact attitude data to the digital flight computer. The avionics system also provides flight termination in case of a major anomaly during ascent.
Block DM-03 Upper Stage
|Re-Starts||Up to 5|
|Engine Dry Weight||300kg|
|Ox to Fuel Ratio||2.48|
|Attitude Control||Two Attitude Control Assemblies|
|Thrust||4 Thrusters per Assembly|
The Block DM-03 Upper Stage represents a modification of the Block-DM Upper Stage that has first flown in 1974 and has undergone a number of major upgrades and re-designs over the decades. Originally, the Block-D originated in the Soviet Union’s lunar exploration plans. It was planned to serve as upper stage on the N1 Moon Rocket to perform burns during Earth-Moon transit.
Today, Block-D Upper Stages fly in a number of configurations, depending on the type of launch vehicle and the particular payload. Currently, Block DM-2, DM-2M, DM-03 are used on the Proton Rocket. Sea Launch uses modified Block-DM-SL Upper Stages on their Zenit 3SL launcher. On Proton-M, the use of Block-D has significantly decreased as the Briz-M upper stage provides an increased Payload Capability to Geosynchronous Transfer Orbit. Overall, Block-D type upper stages have flown more than 250 missions.
The main difference between Briz-M and Block-D is that Briz-M uses storable propellants while Block-D uses Liquid Oxygen and Kerosene. Because of that, Briz-M is more flexible as it can operate for a longer mission duration. Using LOX, Block-D has the problem of oxygen boil-off during flight which limits its capabilities. Although Block-DM provides a higher performance, the more flexible Briz-M can fly a profile that allows it to increase its Payload Capability to GEO, GTO and GSO missions.
Block DM-03 is a modified version of the Block DM-2 featuring larger propellant tanks that can hold about 25% more propellants. The Upper Stage is built to be as small as possible to leave enough room for large payloads under the Payload Fairing. It has a dry mass of 3,500 Kilograms. Block-DM-03 provides a precise injection capability and can support ascent missions of several hours.
The Upper Stage uses Liquid Oxygen as Oxidizer and Rocket Propellant 1 as Fuel. The Propellants are stored in two tanks that are part of the core module of the Vehicle. The LOX tank has a spherical shape; the kerosene tank is toroidal, inclined to 15 degrees for better fuel extraction. In total, 18,600 Kilograms of Propellants are stored in the Block-DM-03’s Tanks.
The Upper stage is powered by a single RD-58M Main Engine. It provides 83.4 Kilonewtons of Thrust. The engine is a pump-fed engine that provides gimbaling capability. The Main Engine can be started up to 5 Times and has a fully redundant ignition system. Attitude Control during cruise phases is provided by two Attitude Control Thrusters that are also used for ullage burns. Each attitude control engine has four nozzles that are grouped in clusters on either side of the main engine. The Attitude Control System uses Nitrogen Tetroxide and Unsymmetrical Dimethylhydrazine as propellants. All aspects of the Block-DM Mission are controlled by the vehicle’s avionics and pre-flight commands/programs. Block-DM has a passive and active thermal control system to keep all of its systems in operating condition during longer flights. After spacecraft separation, the Upper Stage performs Collision avoidance maneuvers or performs a deorbit maneuver, depending on the flight trajectory.
|Separation||During 3rd Stage Burn|
The Payload Fairing is positioned on top of the stacked vehicle and its integrated Payload. It protects the spacecraft against aerodynamic, thermal and acoustic environments that the vehicle experiences during atmospheric flight. When the launcher has left the atmosphere, the fairing is jettisoned by pyrotechnically initiated systems. The fairing is attached to the third stage and the Upper Stage.
Proton-M can be equipped with two different fairing designs. Both are cylindrical in shape, but their overall length and weight varies. Both types of fairing have an inner diameter of 4.35m. The shorter version is 13.31m in length while the large fairing is 15.26m long.
Payload Adapters interface with the vehicle and the payload and are the only attachment point of the payload on the Launcher. They provide equipment needed for spacecraft separation and connections for communication between the Upper Stage and the Payload. The separation system can be based on either the traditional pair of pyrotechnically-initiated bolt cutters or a low-shock Clamp Band Opening Device (CBOD). Four off-the-shelf Payload Adapters are currently available for Proton Flights, however custom designs based on Spacecraft requirements are also provided by Khrunichev, the manufacturer of Proton Adapters.