Energia (GRAU 11K25) was a 1980s super-heavy lift launch vehicle. It was designed by NPO Energia of the Soviet Union as part of the Buran program for a variety of payloads including the Buran spacecraft. Control system main developer enterprise was the Khartron NPO "Electropribor".[4][5] The Energia used four strap-on boosters each powered by a four-chamber RD-170 engine burning kerosene/LOX, and a central core stage with four single-chamber RD-0120 (11D122) engines fueled by liquid hydrogen/LOX.[6]
The launch vehicle had two functionally different operational variants: Energia-Polyus, the initial test configuration, in which the Polyus system was used as a final stage intended to put the payload into orbit, and Energia-Buran,[7] in which the Buran orbiter was the payload and the source of the orbit insertion impulse.
The launch vehicle had the capacity to place about 100 tonnes in Low Earth orbit, up to 20 tonnes to geostationary orbit and up to 32 tonnes by translunar trajectory into lunar orbit.[3] The program was launched in 1976, following the cancellation of the unsuccessful N1 rocket designed for Soviet crewed lunar missions. Energia was the Soviet Union's first successful super-heavy lift launch vehicle, and the world's second, after the US Saturn V.
The launch vehicle made just two flights before being discontinued, carrying Polyus in 1987 and the Buran orbiter in 1988.[7] Since 2016, there have been attempts to revive the launch vehicle. Its RD-170 booster engine was at the time the most powerful rocket engine to use liquid fuel, and scaled-down versions of the RD-170 have been used, with a dual-chamber derivative on the US Atlas III and Atlas V, and single-chamber derivatives on the Russian Angara rockets, US Antares 200, and South Korean Naro-1.
Development history
Work on the Energia/Buran system began in 1976 after the decision was made to cancel the unsuccessful N1 rocket. The facilities and infrastructure built for the N1 were reused for Energia (notably the huge horizontal assembly building), just as NASA reused infrastructure designed for the Saturn V in the Space Shuttle program. Energia also replaced the "Vulkan" concept, which was a design based on the Proton and using the same hypergolic propellants, but much larger and more powerful. The "Vulkan" designation was later given to a variation of the Energia which has eight boosters and multiple stages.
The Energia was designed to launch the Soviet "Buran" reusable shuttle,[7] and for that reason was designed to carry its payload mounted on the side of the stack, rather than on the top, as is done with other launch vehicles. Design of the Energia-Buran system assumed that the booster could be used without the Buran orbiter, as a heavy-lift cargo launch vehicle; this configuration was originally given the name "Buran-T".[8] This configuration required the addition of an upper stage to perform the final orbital insertion.[8] The first launch of the Energia was in the configuration of a heavy launch vehicle, with the large Polyus military satellite as a payload, however Polyus failed to correctly perform the orbital insertion.
Stages/Components
Block A first stage
The first stage, Block A was four strap-on boosters weighing in at 340 tons with fuel included. The boosters had a burn time of 156 seconds from takeoff. They used one RD-170 engine for each booster, four in total. Each booster was 40 meters (131.2 ft) tall and 3.9 meters (12.7 ft) wide. The stage used kerosene as fuel.[6]
The boosters' thrust was 7,906.100 kN in a vacuum.[9]
Block Ts second stage
The second stage, Block Ts was the core/center stage of the rocket weighing in at about 50 tons with fuel included. The stage had a burn time of 470 seconds from takeoff. They had used 4 one-chamber RD-O120 engines. The stage was 59 meters (193.5 ft) tall and 7.75 meters (24.4 ft) wide. The center used liquid hydrogen as fuel instead of the kerosene used in the boosters.[6]
Launch history
First launch (Energia–Polyus)
The Energia was first test-launched on 15 May 1987, with the Polyus spacecraft as the payload. An FGB ("functional cargo block") engine section originally built as a cancelled Mir module was incorporated into the upper stage used to insert the payload into orbit, similarly to Buran and the US Space Shuttle performing the final orbital insertion, since the planned "Buran-T" upper stage had not yet progressed beyond the planning stage.[8] The intended orbit had 280 km (170 mi) altitude and 64.6° inclination.[10]
The Soviets had originally announced that the launch was a successful sub-orbital test of the new Energia booster with a dummy payload, but sometime later it was revealed that in fact the flight had been intended to bring the Polyus into orbit. The two stages of the Energia launcher functioned as designed, but due to a software error in its attitude control system, Polyus's orbital insertion motor failed to inject the payload into orbit. Instead, the Polyus reentered the atmosphere over the Pacific Ocean.[11]
Discontinuation and potential revival
Production of Energia rockets ended with the end of the Buran shuttle project in the late 1980s, and more certainly, with the fall of the Soviet Union in 1991. Since that time, there have been persistent rumors of the renewal of production, but given the political realities, that is highly unlikely.[17]
While the Energia is no longer in production, the Zenit boosters were in use until 2017. The four strap-on liquid-fuel boosters, which burned kerosene and liquid oxygen, were the basis of the Zenit rocket which used the same engines. The engine is the four combustion chamber RD-170. Its derivative, the RD-171, was used on the Zenit rocket. A half-sized derivative of the engine, the two-chamber RD-180, powered the American Lockheed Martin Atlas III vehicle,[18] and still powers the Atlas V rocket, while the single-chamber derivative, the
Proposed variants
Three major design variants were conceptualized after the original configuration, each with vastly different payloads.
Energia-M
The Energia-M was an early-1990s design configuration and the smallest of the three. The number of boosters was reduced from four to two, the core stage was shortened and fitted with just one RD-0120 engine. It was designed to replace the Proton rocket, but lost a 1993 competition to the Angara rocket.[24][25]
A non-functional prototype ("structural test vehicle") of the Energia M still exists in the Dynamic Test Stand facility at Baikonur Cosmodrome.[26]
Energia-2 (GK-175)
Comparison with the Space Shuttle
The Energia rocket was created as a response to the Americans building the Space Shuttle and was heavily based on the already designed Space Shuttle. While the Shuttle was made as a cheaper alternative for spaceflight, the Russians were paranoid about its use as a military weapon and responded by designing and building Energia-Buran.[31]
The Space Shuttle could only bring a maximum 30 tonnes to LEO[32], but the Energia could bring a maximum 100 tonnes to LEO. This makes the Space Shuttle a heavy-lift launch vehicle and the Energia a super-heavy lift launch vehicle.
The Space Shuttle program lasted 30 years, operating from 1981 to 2011. The Energia program began in 1976 and after its only two launches officially ended in 1993 and in total operated for 17 years.[6]
See also
- Comparison of orbital launchers families
- Comparison of orbital launch systems
External links
References
- Mark Wade. Energia Encyclopedia Astronautica, retrieved January 16, 2025^
- Energia Characteristics^
- Launch vehicle "Energia" Official Site^