A Russian Soyuz 2-1A launch vehicle has launched with the Metop-B satellite into orbit for the European Space Agency (ESA) and EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites). The 25th mission of Arianespace’s Starsem affiliate was on schedule, with liftoff at 16:28 GMT on Monday from Baikonur Cosmodrome’s PU-6 LC31 launch complex.
Soyuz 2-1A Mission:
The European operational polar orbiting weather satellite – which has a liftoff mass of approximately 4,085 kg – was designed and manufactured by Astrium.
It was developed as a joint undertaking between ESA and EUMETSAT, and is the second of three nearly identical satellites to provide continuous weather observations until 2020, following MetOp-A – which was orbited by Starsem in October 2006 on a Soyuz mission from Baikonur Cosmodrome.
The satellite also includes instruments delivered by the Centre National d’Etudes Spatiales (CNES) and the National Ocean and Atmosphere Administration (NOAA) from the United States. The Metop satellites form the space segment of the EUMETSAT Polar System.
In addition to service provided by the MetOp spacecraft from polar orbit, EUMETSAT also operates the Meteosat series of satellites in geostationary orbit. Its current Meteosat-8 and Meteosat-9 platforms are positioned over Europe and Africa, while Meteosat-7 is located over the Indian Ocean.
Meteosat-7 – orbited by Arianespace during 1997 from the Spaceport in French Guiana on an Ariane 4 launcher – was the final operational satellite in the Meteosat First Generation (MFG) series of observation platforms that provided reliable imaging of the full Earth disc along with data for weather forecasts during decades.
Meteosat-8 and Meteosat-9 – launched by Arianespace aboard Ariane 5 vehicles from the Spaceport in August 2002 and December 2005, respectively – initiated the Meteosat Second Generation (MSG) satellite series.
They were joined by Meteosat-10, which currently is undergoing a commissioning process after being lofted in July 2012 by Arianespace on another Ariane 5 mission.
The Soyuz-2 is a modernised variant of the Soyuz rocket, itself a derivative of the R-7 Semyorka, the world’s first intercontinental ballistic missile.
The R-7 made its first flight in 1957, and a modified version was used to launch Sputnik 1, the first artificial satellite, later that year. In addition to Soyuz, the R-7 has served as the basis of the Vostok, Molniya and Voskhod rockets as well as several other variants which made small numbers of flights.
Vostok rockets launched early Soviet manned spaceflights, reconnaissance satellites, and a modified version launched the first Soviet lunar probes. Molniya was used to launch missions beyond Earth orbit, as well as military, communications and scientific satellites into high Earth orbits. The Voskhod rocket, which first flew in November 1964, was the predecessor to the Soyuz. It incorporated the Blok I third stage developed for the Molniya rocket, powered by an RD-0108 engine. Voskhod was used to launch reconnaissance satellites, and missions of the manned Voskhod programme.
The Soyuz, meaning “Union”, first flew on 28 October 1966. Derived from the Voskhod, it incorporated upgraded engines, including an RD-0110 on the third stage, as well as a lower-mass and improved telemetry system. The original Soyuz was used exclusively for launches of Soyuz spacecraft, both manned and unmanned. Not including one which exploded on its launch pad after its launch had been delayed, thirty one were launched, the last of which flew in 1975 carrying the Soyuz 23 spacecraft.
Between 1970 and 1971, three Soyuz-L rockets were launched, incorporating reinforcements to the core stages and a larger payload fairing to accommodate prototypes of the LK spacecraft, the spacecraft the Soviet Union intended to use to land men on the Moon. Another Soyuz variant, the Soyuz-M, was developed to launch the Soyuz 7K-VI; the military version of the Soyuz spacecraft, which was heavier than the civilian version.
After the cancellation of the military Soyuz programme, eight Soyuz-M rockets were used to launch Zenit-4MT reconnaissance satellites, with launches occurring between 1971 and 1976.
The Soyuz-U was developed as a standardised launch system, to replace the Voskhod and Soyuz and provide commonality with the Molniya-M. It first flew in May 1973, and in 1976 the original Soyuz, Soyuz-M and Voskhod were all retired, with subsequent launches of their payloads being conducted by Soyuz-U rockets. The Soyuz-U2 configuration, which was optimised to use synthetic propellant allowing it to carry more payload, was introduced in 1982, and used for around 90 launches before being retired in 1995.
With around 750 flights, the Soyuz-U is the most-flown orbital launch system ever developed. It remains in service, and in the last few years it has mostly been used to launch Progress missions to the International Space Station, as well as occasional military payloads. Recent launches have used the Soyuz-U PVB version, which features additional fireproofing.
In 2001, the Soyuz-FG, which featured a new fuel injection system, was introduced, providing an increased payload capacity. After three test flights carrying Progress spacecraft, the Soyuz-FG began launching manned Soyuz-TMA spacecraft to the ISS, a role which it continues to perform.
The Soyuz-2 features modernised engines and digital flight controls. There are three different configurations; the Soyuz-2-1a, 2-1b and 2-1v, with the 2-1a and b using different third stage engines. The Soyuz-2-1v is a two-stage vehicle, without the first stage used in the other configurations, and with an NK-33 engine replacing the RD-108 used on the second stage of the other configurations. It is expected to make its maiden flight next year.
The Soyuz-ST is a derivative of the Soyuz-2 optimised for launching from the Centre Spatial Guyanais, and equipped with a self-destruct system to meet range safety requirements there. The Soyuz-ST made its first launch in October, and can fly in two configurations; the Soyuz-STA and STB, based on the Soyuz-2-1a and 2-1b respectively.
The Soyuz-2 made its maiden flight in 2004, in the Soyuz-2-1a configuration. It carried an obsolete Zenit-8 reconnaissance satellite, refitted with test instrumentation, on a suborbital trajectory. It is not entirely clear whether the mission was intended to be suborbital, or whether the rocket actually failed to achieve orbit.
The first launch into orbit occurred in October 2006, when a Soyuz-2-1a/Fregat deployed the MetOp-A weather satellite. The Soyuz-2-1b made its maiden flight later the same year, carrying the COROT exoplanet detection satellite.
Under Russian stage numbering, the booster rockets which augment the core stage’s thrust during the first 118 seconds of flight are considered to be its first stage, even though the core, or second stage, ignites at the same time. The first stage consists of four strap-ons, designated Blok-B, V, G and D, which are powered each powered by an RD-107A engine. The first stages are attached around the second stage, or Blok-A, which is powered by a single RD-108A. All of the first three stages of the Soyuz burn RP-1 propellant, using liquid oxygen as an oxidiser.
The first and second stages ignite about 17-20 seconds before launch, and slowly build up thrust. Once full thrust has been achieved, the launch pad’s four swing arms will release the rocket to begin its ascent to orbit. Eight seconds after lifting off, the rocket will pitch over. After burning for 118.25 seconds, the first stage will be jettisoned, forming a pattern in the sky known as the “Cross of Korolev” as the four boosters separate from the core.
The second stage will continue to burn for another 168.94 seconds before separating from the third stage, which will have ignited about two seconds ahead of staging. The third stage is a Blok-I, which is powered by a single RD-0110 engine. It is expected to burn for 243.9 seconds, before Fregat separation occurs. Near the start of third stage flight, about 9.66 seconds after second stage separation, the “aft section” or interstage will be jettisoned from the Blok-I. Fairing separation will also occur during third stage flight, about four minutes and fifty eight seconds after liftoff.
The Fregat upper stage, which is propelled by unsymmetrical dimethylhydrazine and nitrogen tetroxide fuelling an S5.98M engine, will be used to place the satellite into their target orbit. The Fregat, which is making its thirty first flight, has been used as a fourth stage on Soyuz-U, Soyuz-FG and Soyuz-2 rockets, and also as the third stage of the Zenit-3F.
Fregat made its first flight in first flew in 2000, on a Soyuz-U rocket carrying the IRDT inflatable heat shield experiment. The Fregat was also equipped with a prototype heat shield, and was intended to be recovered if possible; however it could not be found after reentry. The heat shield was a one-off on the test flight; Fregats are generally allowed to burn up in the atmosphere.
Only two launches of Fregats have failed to date. One of these, the Soyuz-2-1b launch, failed before the Fregat had even fired, and the upper stage was not responsible for the anomaly.
The other failure was caused by the Fregat; the May 2009 launch of the Meridian 2 satellite ended in failure after a programming error led to the Fregat expending propellant at a greater rate than it should have, and it ran out of fuel during the second of three planned burns.
The propulsion system of the Fobos-Grunt spacecraft, which failed to depart Earth orbit on a mission to Mars’ moon Phobos, was also based on the Fregat, however it was modified, and it is unclear what the cause of the spacecraft’s failure was.
(Images via ESA and L2)