written by Justin Mooney February 5, 2023
https://www.nasaspaceflight.com/2023/02/elektro-l4/
At 09:12 UTC on Feb. 5, 2023, a Proton-M launched from Site 81/24 at the Baikonur Cosmodrome, carrying the fourth Elektro-L satellite to geostationary Earth orbit (GEO).
Sunday’s launch is the first of up to three Proton launches planned for 2023, with the next being Olymp-K 2 scheduled for March. The Proton-M launcher is nearing retirement, with a limited number of vehicles left available to launch over the next few years.
Elektro-L Satellites
Elektro-L is a series of meteorological satellites developed for Roscosmos, the Russian Federal Space Agency. These are the first Russian meteorological satellites to operate in a geostationary orbit, and only the second operational series of Russian weather satellites.
Each satellite has a mass of around 1,620 kg and a design life of 10 years. They are capable of taking images of a full hemisphere of the Earth in both visible and infrared spectra, providing data on climate change and ocean monitoring, in addition to providing weather forecasting data.
The Elektro-L satellites were developed by NPO Lavochkin and are operated by Roscosmos. They operate in conjunction with the Meteor-M series of polar-orbiting weather satellites. The data gathered from the satellites is distributed to the Scientific Research Center of Space Hydrometeorology “Planeta” and the Federal Service for Hydrometeorology and Environmental Monitoring of Russia.
Elektro-L4 satellite. (Credit: NPO Lavochkin)
Elektro-L satellites have a modular design, with independent service and payload modules. The solar panel provides 1.7kW of power. The service module, called Navigator, is built by NPO Lavochkin and is a standardized platform that can serve as the service module for other Russian satellites, including the space telescope Spektr-R.
The imaging system, MSU-GS, provides a resolution of 1 km per pixel for the two visible bands, and 4 km per pixel for eight infrared bands. Images are normally taken once every 30 minutes, but images can be taken once every 10 minutes in emergencies.
The Elektro-L satellites were preceded by the Elektro-1 satellite, which was launched in 1994, but never became fully operational.
Elektro-L Launch History
The first satellite in the Elektro-L series was launched on Jan. 20, 2011, from Pad 45 at Baikonur Cosmodrome. The Zenit-2SB launch vehicle featured a new third stage, the Fregat-SB, a variation of the Fregat stage designed for use on Zenit rockets. One day later, the deputy head of Roscosmos announced that the satellite had completed the first series of tests, and was now fully operational.
The next satellite, Elektro-L № 2, was initially scheduled to launch in 2013, but it was delayed and eventually launched on Dec. 11, 2015, aboard a Zenit-3F with the Fregat-SB upper stage. This was Zenit-3F’s 83rd and second-to-final launch.
The third satellite was launched on Dec. 24, 2019, by a Proton-M with the DM-3 upper stage.
Proton-M launch vehicle at the pad in Baikonur readying for launch. (Credit: Roscosmos)
Proton Rocket
The Proton rocket, formally designated UR-500, is an expendable heavy-lift launch vehicle initially designed as a “super heavy ICBM.” Due to its large size, it was never deployed as an ICBM and was instead turned into a launch vehicle, proposed to launch crewed missions to the Moon. The Proton-M launch vehicle for this mission had the serial number 93568 with Blok DM-03 upper stage number 7L.
Proton rockets have an unusual appearance due to most Russian rocket components being transported by rail. The first stage consists of a central oxidizer tank, which is the maximum width that can be transported by rail, with six fuel tanks surrounding it. The first stage is powered by six RD-275 engines attached to the fuel tanks, producing a max thrust of 10,470 kN. Despite the fuel tanks resembling strap-on boosters like those used by the American Atlas V rocket, the tanks are not designed to separate from the central tank.
The second stage is powered by three RD-0210 engines along with a single RD-0211, producing a maximum thrust of 2,399 kN. Attached to the first stage with a lattice structure, the second stage “hot stages,” a process in which the second stage engines ignite shortly before separating from the first stage. The third stage of the rocket is powered by an RD-58M, producing a maximum thrust of 83.4 kN.
Each stage of the Proton rocket is fueled by the toxic combination of unsymmetrical dimethyl hydrazine (UDMH) and nitrogen tetroxide (N2O4). Both UDMH and N2O4 are hypergolic fuels that ignite on contact, removing the need for an ignition system, and can be stored at ambient temperatures. With fuels that do not need to remain chilled, the rocket can stay on the pad indefinitely. Other rockets to use hypergols include the US Titan II, III, and IV, the Chinese Chang Zheng 2 and 4, and the European Ariane 1 to Ariane 4.
Proton also features an optional fourth stage, which itself has multiple variants. The Proton-K rocket could fly with the Blok D, DM, DM2, or DM-2M. The Blok D stage was used for interplanetary missions and lacked a guidance module, relying on the probe to control the flight. Blok DM, DM2, and DM-2M were used for high Earth orbits and featured toroidal fuel tanks — located around the engine and behind the oxidizer tank. Proton-K launched every Salyut space station and nearly all of the modules for the Mir space station, with the exception of the docking module, which was launched on the Space Shuttle. Both the Zarya and Zvezda modules were launched to the International Space Station (ISS) on a Proton-K.
Proton-M was introduced in April of 2001, featuring lower first-stage mass and upgraded engines, allowing the rocket to lift heavier payloads into orbit. A new fourth stage, the Briz-M, was introduced, with hypergolic propellants, eliminating the need to supply multiple fuel types and oxygen top-offs as the liquid oxygen boiled off.
Proton launch vehicles and Briz-M upper stages are developed and built by the Khrunichev State Research and Production Space Center in Moscow. Khrunichev is a majority owner in International Launch Services, the company that marketed commercial Proton launches, and the center houses all engineering, assembly, and test facilities needed for Proton production.
In February 2009, a new enhanced variant of Proton, the Phase III Proton-M/Briz-M, was introduced, launching the Ekspress-AM44 and MD-1 satellites, and launching the commercial payload of Echostar XIV in March 2010. This configuration allows the rocket to lift 6,150 kg to a geostationary transfer orbit, an increase of 1,150 kg over the original Proton-M/Briz-M.
Between 2010 and 2015, there were 8 failures of the Proton rocket. Three of the eight failures were due to issues with the third stage, with one failure associated with the first stage. On July 2, 2013, a Proton-M launching three GLONASS navigation satellites experienced a failure where the rocket started to pitch side to side until it eventually was headed directly towards the ground, crashing near Area 39 at the Baikonur Cosmodrome. An investigation into the anomaly revealed that some of the rate gyro packages on the booster were installed upside down.
(Lead photo: Proton-M launches. Credit: Roscosmos)