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<\/p>\nRussia\u2019s Soyuz rocket has made its second launch in less than twenty-four hours, delivering a missile detection satellite to orbit Thursday in a military launch from the Plesetsk Cosmodrome. Soyuz lifted off at 10:46 Moscow Time (07:46 UTC), placing the Tundra satellite into its planned orbit with the aid of a Fregat upper stage.<\/p>\n
Tundra plays a significant part in Russia\u2019s national security arrangements, monitoring the Earth for potentially hostile missile launches so the Russian Government can react as necessary. It forms part of the Edinaya Kosmicheskaya Sistema (EKS) or Unified Space System which is being introduced to replace the earlier Oko system that Russia inherited from the Soviet Union. Thursday\u2019s launch deployed the third such satellite.<\/p>\n
The Tundra satellites are being built by RKK Energia. They are built around the Viktoria platform, a satellite bus derived from a series of Yamal communications satellites developed in the late 1990s. Like their US counterparts in the Space-Based Infrared System (SBIRS), Tundra satellites carry infrared telescopes that are used to detect and track heat sources that could be missiles launching and in flight. Optical and ultraviolet instruments collect complimentary data.<\/p>\n
As well as detecting that missiles have been launched, Tundra\u2019s sensors allow it to track their flight so that potential targets can be determined more rapidly than if ground-based radar was being relied upon. This is a significant improvement over the previous-generation satellites which could only detect the missiles.<\/p>\n
Like the two spacecraft that preceded it, this third Tundra satellite has been placed into Molniya orbit. This is a special class of highly elliptical orbit with an orbital period of twelve hours \u2013 meaning the satellite completes two revolutions per day \u2013 and inclination of 63.4 degrees. The combination of orbital parameters cancels out the precession of its argument of perigee, meaning that the apogee \u2013 or highest point \u2013 of its orbit is locked in place over the Northern hemisphere.<\/p>\n
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A rare view of a Tundra satellite via a model photographed by Moscow Times<\/p>\n
The highly elliptical nature of the orbit ensures the satellite spends most of its time close to apogee. Tundra uses an orbit with a perigee \u2013 or lowest point \u2013 of 1,620 kilometers (995 miles, 864 nautical miles) and an apogee of 38,500 kilometers (23,900 miles, 20,800 nautical miles).<\/p>\n
The first two Tundra satellites were launched in November 2015 and May 2017. Before that, eighty-six US-K satellites were deployed under the Oko system from 1972 to 2010. Oko used additional satellites in geosynchronous orbit to gather further data, and while no such satellites have yet been deployed for EKS they are believed to be under development.<\/p>\n
Now it is in orbit, the Tundra satellite is expected to be renamed Kosmos 2541, following a system of designations that Russia has used for its military satellites as far back as 1962. Kosmos numbers are assigned sequentially to obfuscate the purpose of military spacecraft, with the most recent designation prior to Thursday\u2019s launch being the assignment of Kosmos 2540 to a Geo-IK spacecraft launched at the end of August.<\/p>\n
Historically the Kosmos system was also used for interplanetary missions that had failed to depart Earth\u2019s orbit and for prototype spacecraft of various types. However, in recent years the system has been used exclusively for military satellites.<\/p>\n
Space tourism guides (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n Tundra rode to orbit aboard a Soyuz-2-1b rocket with a Fregat-M upper stage. This is one of three variants of the Soyuz design that make up the Soyuz-2 family, which following Wednesday\u2019s retirement of the earlier Soyuz-FG configuration are now the only Soyuz vehicles still in service. First flown in 2004 on a suborbital test flight, the Soyuz-2-1a introduced digital flight control systems for the first time on Soyuz, along with upgraded first and second stage engines.<\/p>\n Soyuz 2-1b during a previous launch \u2013 photo from Roscosmos<\/p>\n The Soyuz-2-1b further upgrades the rocket with a new third stage engine, allowing it to carry heavier payloads. The third configuration, Soyuz-2-1v, is optimized for carrying smaller payloads at lower cost.<\/p>\n The launch took place from Site 43\/4 at the Plesetsk Cosmodrome in Northern Russia. This is the only one of Plesetsk\u2019s original four Soyuz pads that remains in operation \u2013 although its sister pad, 43\/3, is currently undergoing final testing ahead of its return to service early next year.<\/p>\n Prior to launch, Soyuz was assembled horizontally in an assembly facility, or MIK, away from the launch pad. A few days before liftoff the rocket was moved into position by train, raised to vertical and mounted on the launch pad.<\/p>\n When the time came, engines on the first and second stages ignited about sixteen seconds before liftoff. The first stage of Soyuz is made up of the four boosters that are clustered around its core \u2013 which is the second stage. The boosters are designated Blok-B, V, G and D, with each housing an RD-107A engine. The second stage is powered by the closely-related RD-108A which incorporates four additional vernier chambers for attitude control purposes. These engines burn RG-1 propellant \u2013 a refined form of kerosene \u2013 and liquid oxygen.<\/p>\n Following ignition, the engines slowly built up to full thrust. Once the countdown reached zero Pad 43\/4\u2019s swing arms came open and Soyuz began her climb towards orbit. The first stage burned for about 118 seconds before exhausting its supply of propellant.<\/p>\n<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/09\/NSF-2019-09-26-05-14-15-629.jpg\")
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