{{short description|Soviet (now Ukrainian) RP-1/LOX fueled rocket, for satellite launch}} {{about|the orbital carrier rocket family|other uses|Zenit (disambiguation)}}
{{Infobox rocket |image = Zenit-2 rocket ready for launch.jpg |caption = Zenit-2 rocket ([[Baikonur Cosmodrome|Baikonur]], 10 December 2001) |name = Zenit |function = [[Medium-lift launch vehicle|Medium-lift]] [[expendable launch vehicle|expendable]] [[carrier rocket]] |manufacturer = {{plainlist| * [[Yuzhnoye Design Office|Yuzhnoye]] (design) * [[Yuzhmash]] (manufacturing) }} |country-origin = {{plainlist| * Zenit-2: [[USSR]], [[Ukraine]] * Zenit-3SL: [[Ukraine]] }} |height = {{cvt|57–59.6|m}} |diameter = {{cvt|3.9|m}} |mass = {{cvt|444,900–462,200|kg}} |stages = 2 or 3
|capacities = {{Infobox rocket/payload |location = [[Low Earth orbit|LEO]] |kilos = Zenit-2: {{cvt|13,740|kg}} }} {{Infobox rocket/payload |location = [[Sun-synchronous orbit|SSO]] |kilos = Zenit-2: {{cvt|11,380|kg}} }} {{Infobox rocket/payload |location = [[Geostationary transfer orbit|GTO]] |kilos = Zenit-3SL: {{cvt|6,000|kg}} }}
|status = Suspended |sites = {{plainlist| * [[Baikonur Cosmodrome|Baikonur]] [[Baikonur Cosmodrome Site 45|LC-45]] * [[Odyssey (launch platform)|Odyssey]] (ocean platform) }} |launches = {{plainlist| * '''84''' * 36 Zenit 2 * 36 Zenit 3SL * 2 Zenit 2M * 6 Zenit 3SLB * 4 Zenit 3F }} |success = {{plainlist| * '''71''' * 28 Zenit 2 * 32 Zenit 3SL * 2 Zenit 2M * 5 Zenit 3SLB * 4 Zenit 3F }} |fail = {{plainlist| * '''10''' * 7 Zenit 2 * 3 Zenit 3SL }} |partial = {{plainlist| * '''3''' * 1 Zenit 2 * 1 Zenit 3SL * 1 Zenit 3SLB<ref>{{cite web|url=http://izvestia.ru/news/news173271 |script-title=ru:Израиль корит Роскосмос за невыполненные обязательства |date=2008-05-06 |publisher=Izvestia |language=ru |access-date=2008-05-09 |url-status=dead |archive-url=https://web.archive.org/web/20080510132234/http://www.izvestia.ru/news/news173271 |archive-date=May 10, 2008 }}</ref> }} |first = {{plainlist| * Zenit 2: 13 April 1985 * Zenit 3SL: 28 March 1999 * Zenit 2M: 29 June 2007 * Zenit 3SLB: 28 April 2008 * Zenit 3F: 20 January 2011 }} |last = {{plainlist| * Zenit 2: 10 June 2004 * Zenit 3SL: 26 May 2014 * Zenit 2M: 8 November 2011 * Zenit 3SLB: 31 August 2013 * Zenit 3F: 26 December 2017 }}
|stagedata = {{Infobox Rocket/Stage |type = Stage |stageno = First |height = {{cvt|32.9|m}} |engines = 1 [[RD-171]] |thrust = {{convert|8180|kN}} |SI = {{convert|337|isp}} |burntime = 150 seconds |fuel = [[RP-1]] / [[LOX]] }} {{Infobox Rocket/Stage |type = Stage |stageno = Second |height = {{cvt|11.047|m}} |engines = 1 [[RD-120]]<br/>1 [[RD-8]] |thrust = {{convert|912|kN}}<br/>{{convert|79500|N}} |SI = {{convert|349|isp}} |burntime = 315 seconds |fuel = [[RP-1]]/[[LOX]] }} {{Infobox Rocket/Stage |name = [[Block DM-SL]] |diff = Zenit-3SL/3SLB |type = Stage |stageno = Third |engines = 1 [[RD-58M]] |thrust = {{convert|84900|N}} |SI = {{convert|352|isp}} |burntime = 650 seconds |fuel = [[RP-1]] / [[LOX]] }}{{Infobox Rocket/Stage |name = [[Fregat|Fregat-SB]] |diff = Zenit-3F |type = Stage |stageno = Third |engines = 1 [[S5.92]] |thrust = {{convert|19600|N}} |SI = {{convert|327|isp}} |burntime = 877 seconds |fuel = {{N2O4}} / [[UDMH]] }} }}
'''Zenit''' ({{langx|uk|Зеніт}}, {{langx|ru|Зени́т}}; meaning ''Zenith'') was a family of space [[launch vehicle]]s designed by the [[Yuzhnoye Design Bureau]] in [[Dnipro]], [[Ukraine]], which was then part of the [[Soviet Union]]. Zenit was originally built in the 1980s for two purposes: as a [[liquid rocket booster]] for the [[Energia (rocket)|Energia]] rocket and, equipped with a second stage, as a stand-alone middle-weight launcher with a payload greater than the 7 tonnes of the [[Soyuz (rocket)|Soyuz]] but smaller than the 20 tonnes payload of the [[Proton (rocket family)|Proton]]. The last rocket family developed in the USSR, the Zenit was intended as an eventual replacement for the dated Soyuz and Proton families, and it would employ propellants which were safer and less toxic than the Proton's nitrogen tetroxide/UDMH mix. Zenit was planned to take over crewed spaceship launches from Soyuz, but these plans were abandoned after the [[dissolution of the Soviet Union]] in 1991.
Many of components of the Zenit rockets were produced in Russia. The Ukrainian space industry was highly integrated with that of Russia due to its Soviet heritage, but that cooperation was interrupted by the [[Russo-Ukrainian War]] beginning in 2014, which has effectively led to a hiatus in the Zenit program.<ref>{{Cite web |last=Bodner |first=Matthew |date=June 6, 2016 |title=How Crimea's annexation hurt Ukraine's space program |url=https://spacenews.com/from-the-archives-how-crimeas-annexation-hurt-ukraines-space-program/ |access-date=2024-04-02 |website=SpaceNews |language=en-US}}</ref> The subsequent [[Russian invasion of Ukraine]] in 2022 saw damage to its manufacturing facilities due to Russian missile strikes, and what survived those strikes pivoted to producing military weapons.<ref>{{Cite web |last=Pultarova |first=Tereza |date=2023-08-27 |title=Lost partnerships destroying Ukraine's space sector faster than Russian missiles, former space chief says |url=https://www.space.com/ukraine-space-sector-threatened-lost-partnerships |access-date=2024-04-02 |website=Space.com |language=en}}</ref>
Zenit-3SL was launched by the [[Sea Launch]] consortium's floating launch platform in the [[Pacific Ocean]] and Zenit-2 was launched from [[Baikonur Cosmodrome]] in [[Kazakhstan]]. [[RD-171M]] engines of the Zenit's first and second stages as well as the upper stage of the Zenit-3SL rocket were supplied by Russia. An improved Zenit-3SLB rocket was used for commercial launches from Baikonur Cosmodrome beginning in April 2008, marketed as [[Land Launch]].<ref name=landlaunchuserguide2014>{{cite web|url=http://www.landlaunch.ru/download/llug_eng.pdf|title=Land Launch User's Guide Revision B|date=1 October 2014|publisher=Space International Services|access-date=8 February 2015|url-status=dead|archive-url=https://web.archive.org/web/20160625025453/http://www.landlaunch.ru/download/llug_eng.pdf|archive-date=25 June 2016}}</ref>
Zenit-3SL was launched 36 times with 32 successes, one partial success, and three failures. The first failure, the launch of a [[Hughes Aircraft|Hughes]]-built communications satellite owned by [[ICO Satellite Management|ICO Global Communications]], occurred during the second commercial launch on March 12, 2000, and was blamed on a software error that failed to close a valve in the second stage of the rocket. The second failure occurred on January 30, 2007, when the rocket exploded on the [[Odyssey (launch platform)|Odyssey]] launch platform, seconds after engine ignition. The [[NSS-8]] communication satellite on board was destroyed.<ref name="harvey">{{Cite book | last = Harvey | first = Brian | year = 2007 | title = The Rebirth of the Russian Space Program | publisher = Praxis | location = Chichester, UK | pages = 167–175 }}</ref>
On September 24, 2011 [[Zenit-3SL]] launched successfully from the [[Odyssey (launch platform)|Odyssey]] launch platform under a renewed [[Sea Launch]] project with [[RSC Energia]] as the majority stakeholder. The rocket delivered the European communication satellite Atlantic Bird 7 to its planned orbit. On February 1, 2013, another Zenit-3SL failed while launching the [[Intelsat 27]] satellite.<ref>{{cite web|url=http://www.nasaspaceflight.com/2013/02/sea-launch-zenit-3sl-launch-intelsat-27/|title=Sea Launch Zenit 3SL with Intelsat 27 fails during first stage flight|first=Chris|last=Bergin|publisher=NASASpaceflight.com|date=1 February 2013|access-date=1 February 2013}}</ref>
== History ==
The Zenit-2 was the first Zenit to be designed for use as an orbital carrier rocket. It consists of two stages. The first uses an [[RD-171]] engine, and an [[RD-120]] engine powers the second stage. It first flew on 13 April 1985, two years before the Energia, due to delays relating to the Energia's development.{{citation needed|date=February 2015}} Zenit-2 would be certified for crewed launches and placed in specially built [[launch pad]] at [[Baykonur]] spaceport, carrying the new crewed partially reusable [[Zarya (spacecraft)|Zarya]] spacecraft that developed in end of the 1980s but was canceled. Also in the 1980s [[Vladimir Chelomey]]'s firm proposed never realised 15-ton [[Uragan (spaceplane)|Uragan]] spaceplane launched by Zenit-2.
Two launch facilities were constructed for the Zenit at Baikonur, but the second was only ever used twice. On October 4, 1990, an attempted launch of a Tselina-2 naval reconnaissance satellite ended in disaster as the booster suffered a first stage engine failure seconds into launch and fell back onto the pad, which was severely damaged in the ensuing explosion. The failure was traced to a leak in a LOX line that caused a fire in the thrust section of the booster. Estimated repair costs were about 45 million rubles, but the collapse of the Soviet Union meant that there were no funds available, so the pad was abandoned.
Following two failures in 1991–92 both caused by the second stage, the Zenit was on the verge of being cancelled entirely, but a successful flight in November 1992 saved the program.
The rate of Zenit launches slowed to a trickle during the 1990s due to the severely cash-strapped Russian Federation, and also because of Russia's reluctance to fly military payloads on a booster manufactured in now-independent Ukraine. On May 20, 1997, a launch of a Tselina-2 satellite failed when the first stage shut down 48 seconds into launch. The booster crashed downrange.
During the 2000s, Zenit would find a new lease on life as the basis of the international Sea Launch project whereby commercial flights would be undertaken from an offshore launch platform. The basic Zenit booster received several upgrades to the propulsion and avionics systems for Sea Launch as well as a third stage, and the first test with a dummy payload was carried out on March 27, 1999. In October, a Direct TV 1-R satellite was orbited successfully. An ICO F-1 comsat was lost in March 2000 due to a second stage guidance malfunction. There followed eight consecutive successful launches until Apstar 5 in 2004 suffered a premature third stage shutdown that left it in an incorrect orbit, but the satellite's onboard engines corrected it.
After nine successful launches, the Zenit produced a repeat performance of the 1990 disaster when on January 30, 2007, the first stage lost thrust and exploded. The flame deflector on the Sea Launch platform broke off and sank into the water. Loose debris had been sucked into a turbopump, resulting in engine failure.
By the late 2000s, the Zenit program at Baikonour was reviving and would see considerable success.
On February 1, 2013, an Intelsat satellite launched from the Sea Launch Odyssey platform in the equatorial Pacific. The nighttime launch performed nominally for about 20 seconds when the first stage abruptly lost thrust. Approximately 40 seconds after liftoff, all telemetry data ceased. Subsequent investigation showed that the Zenit had begun deviating from its flight path when the pitch and roll maneuver started. The onboard computer sensed an abnormal situation and sent an automatic shutdown command to the first stage at T+23 seconds, and impact with the ocean occurred about one minute after liftoff. Ultimately, the failure was traced to a defective hydraulic pump that controlled gimbaling of the first stage engines. This resulted in the booster starting an uncontrolled rolling motion which caused the computer system to terminate all thrust. Although anomalous conditions began around T+11 seconds, the Zenit's flight computer was "locked" to prevent engine shutdown until at least 20 seconds after liftoff so the booster would not come down on or near the launch complex. Impact occurred about two miles downrange, but attempts to recover booster debris were unsuccessful.
In February 2015, following a year of strained relations as a result of a [[2014–15 Russian military intervention in Ukraine|Russian military intervention into Ukraine]], Russia announced that it would discontinue its "joint program with Ukraine to launch [[Dnepr (rocket)|Dnepr rocket]]s and [was] no longer interested in buying Ukrainian Zenit boosters, deepening problems for [Ukraine's] space program and its struggling [[Yuzhmash]] factory."<ref name=pa20150206>{{cite news |last1=Messier |first1=Doug |title=Russia Severing Ties With Ukraine on Dnepr, Zenit Launch Programs |url=http://www.parabolicarc.com/2015/02/06/russia-severing-ties-ukraine-dnepr-zenit-launch-programs/ |access-date=8 February 2015 |work=Parabolic Arc |date=6 February 2015 |archive-date=15 February 2015 |archive-url=https://web.archive.org/web/20150215052356/http://www.parabolicarc.com/2015/02/06/russia-severing-ties-ukraine-dnepr-zenit-launch-programs/ |url-status=dead }}</ref>
Strained relations between Ukraine and Russia after 2014 have led to [[Russian Federal Space Agency]] intending to purchase no more of the Zenit first-stage boosters made by Yuzhmash (powered by Russian engines). However 2 Zenit rockets that have been delivered to Russia for [[Russian Federal Space Agency]] missions will still be used; another Zenit rocket for launching a Ukrainian satellite has been completed but without engines due to lack of funding for payments.<ref>{{cite news|title=Russia No Longer Interested In Ukrainian Built Launch Vehicles |url=http://www.satnews.com/story.php?number=1637484549 |access-date=10 February 2015 |work=SatNews |date=3 February 2015 }}</ref> The world market for Zenit launch vehicles has shriveled since Sea Launch suspended operations, and the future of Zenit is uncertain.<ref>{{cite web|url=https://spacenews.com/from-the-magazine-ukraines-untethered-orbital-manuevers-how-crimea-hurt-ukraines-space-program/|title=How Crimea fractured Ukraine's space program|date=7 June 2016|website=SpaceNews.com}}</ref>
Despite the ongoing conflict between the two governments, a Zenit rocket was launched in December 2017, after a two-year hiatus, to deliver [[AngoSat 1]].<ref name="Angosatlaunchzak">{{cite web|last1=Zak|first1=Anatoly|title=Zenit delivers Angosat-1, but the spacecraft breaks contact with ground control|url=http://www.russianspaceweb.com/zenit-angosat-launch.html|website=Russian Space Web|access-date=28 December 2017}}</ref>
==Production== The first and the second stages of the Zenit were designed by Yuzhnoye and are manufactured by [[Yuzhmash]].<ref name=sl25>{{cite web |url=http://www.yuzhnoye.com/index.php?idD=48&id=124&path=News/News_e&lang=en |title=Sea Launch: the Twenty-Fifth Launch of Zenit-3SL |date=2008-01-21 |publisher=Yuzhnoye |url-status=dead |archive-url=https://web.archive.org/web/20131111054341/http://www.yuzhnoye.com/index.php?idD=48&id=124&path=News/News_e&lang=en |archive-date=2013-11-11 }}</ref>
==Variants==
===Zenit-2=== {{main|Zenit-2}} The Zenit-2 was the first member of the rocket family. It consists of two stages. The first uses an [[RD-171]] engine, and an [[RD-120]] engine powers the second stage. It first flew on 13 April 1985, carrying a [[Tselina-2]] mass simulator. However the test flight was unsuccessful. The first successful flight occurred on 22 October 1985.
===Energia booster=== {{Broader|Buran programme}} The Zenit first stage was used as a strap-on booster rocket for the [[Energia (rocket)|Energia carrier rocket]].<ref>{{cite book|author1=Bart Hendrickx|author2=Bert Vis|title=Energiya-Buran: The Soviet Space Shuttle|url=https://books.google.com/books?id=VRb1yAGVWNsC|year=2007|publisher=Springer Science & Business Media|isbn=978-0-387-73984-7}}</ref> Four Zenit first stages were attached to the core vehicle to produce extra thrust at lift-off, in the same way that [[Shuttle SRB|Solid Rocket Boosters]] were used on the US [[Space Shuttle]]. Energia made two flights (1987 and 1988) before the programme was abandoned.
===Zenit 2M and 2SLB=== {{main|Zenit-2M}} '''Zenit 2M''' is a new version of the Zenit 2 with an upgraded control system and modernized engines.<ref> {{cite web|url=http://www.spaceflightnow.com/news/n0706/29zenit/|title=Ukrainian Zenit rocket makes its return to flight|publisher=Spaceflight Now}}</ref> The first Zenit 2M was launched on June 29, 2007, carrying a classified Russian military [[Tselina-2]] satellite. The Zenit-2SLB designation applies to commercial launches through the [[Land Launch]] subsidiary of Sea Launch, which began satellite launches from Baikonur Cosmodrome in 2008.<ref name="landlaunchuserguide2014" />
===Zenit-3SL=== {{main|Zenit-3SL}} '''Zenit-3SL''' is a three-stage [[launch vehicle|carrier rocket]] developed for and used by the Sea Launch consortium.
It combines:<ref> {{cite web |url=http://www.sea-launch.com/news_releases/nr_070903.html |title=Sea Launch Receives Zenit-3SL Hardware for Next Launches |publisher=Sea Launch |url-status=dead |archive-url=https://web.archive.org/web/20070927204518/http://www.sea-launch.com/news_releases/nr_070903.html |archive-date=2007-09-27 }}</ref> * two-stage Zenit-2S built by [[Ukraine]]'s SDO [[Yuzhnoye Design Bureau|Yuzhnoye]]/PO [[Yuzhmash]] * [[Block DM-SL]] upper stage, provided by Russia's [[S.P. Korolev Rocket and Space Corporation Energia|Energia]] * nose-cone enclosure for protection of payload during launch, provided by [[Boeing]].
Rockets used by Sea Launch are assembled in [[Long Beach, California]]. Launches occur from the ''Ocean Odyssey'' offshore launch platform, situated at the equator. ''Ocean Odyssey'' is also used to transport rockets to the launch site. The [[List of Zenit launches|most recent launch]] of a Zenit-3SL occurred on 11 December 2015. The RD-171 engine of the Zenit-3SL first stage, and most of the control system of -3SL missiles were made in Russia.<ref>{{cite web|url=http://www.pravdareport.com/business/138261-ukraine_antonov/|title=Ukraine kills Antonov aircraft maker|first=Dmitry|last=Sudakov|date=26 July 2017|website=PravdaReport|access-date=4 May 2019|archive-date=27 November 2020|archive-url=https://web.archive.org/web/20201127225658/https://www.pravdareport.com/business/138261-ukraine_antonov/|url-status=dead}}</ref> However, according to the same source, it is not clear if Russia's component suppliers are still working together with Yuzhmash as of this date.
===Zenit 3M and 3SLB=== {{main|Zenit-3SLB}} The Zenit-3M is a Zenit-2M with the [[Block-DM]] upper stage used on the Zenit-3SL. It is launched from Baikonur. The maiden flight was launched on 28 April 2008. [[Land Launch]] commercially market the Zenit-3M under the designation Zenit 3SLB.<ref name=landlaunchuserguide2014/>
===Zenit-3F=== {{main|Zenit-3F}} The Zenit-3F, also known as the Zenit-2SB/Fregat, is a 3-stage derivative of the Zenit-2M, using a [[Fregat]] upper stage, as already used on the [[Soyuz (rocket family)|Soyuz]], to propel spacecraft to higher orbits. It made its maiden flight in January 2011, with the [[Elektro-L No.1]] spacecraft for the Russian government. Later the same year, another launch carried [[Spektr-R]], a {{convert|5000|kg|lb|adj=on}} [[space telescope]], into an orbit with a [[perigee]] of {{convert|10000|km|mi}} and an [[apogee]] of {{convert|390000|km|mi}}.<ref>{{cite web |url=http://www.asc.rssi.ru/radioastron/description/design_eng.htm |title=Spacecraft Design |publisher=Astro Space Center of Lebedev Physical Institute}}</ref> The most recent launch occurred on 26 December 2017 from Baikonur Cosmodrome when the rocket lifted off with the Angolian Angosat 1 spacecraft.<ref>{{cite web |url=https://spaceflightnow.com/2017/12/26/angolas-first-communications-satellite-ready-for-launch-tuesday/ |title=Angola's first communications satellite lifts off from Kazakhstan |publisher=Spaceflightnow}}</ref>
==Specifications==
===Overview=== {| class="wikitable" |- ! ! Zenit-2 ! Zenit-3SL |- ! Stages | 2 | 3 |- ! Total length | 57 [[meters|m]] | 59.6 m |- ! Total empty mass | 37,600 [[kilogram|kg]] | 40,320 kg |- ! Total gross mass | 444,900 kg | 462,200 kg |- ! Payload | 13.74 [[tonne]] to [[Low Earth orbit|LEO]] |≈6 tonne to [[Geostationary transfer orbit|GTO]] |- ! Launch site | [[Baikonur Cosmodrome]] | [[Sea Launch]] ocean platform |- ! Launches | 21 (6 failed) as of 10 June 2004 | 31 (3 failed, 1 partial success)<br>as of 1 February 2013 |- ! Success ratio | 71.4% | 91.1% |- ! Price per launch | ~$45 million | ~$90 million |}
===Payload capacities===
====Two stage version (Zenit-2)==== {| class="wikitable" |- ! colspan="2" | [[Payload (air and space craft)|Payload]] to [[Low Earth orbit|LEO]] | 13,740 kg |- ! colspan="2" | Payload to [[Polar orbit|PEO]] | 5,000 kg |- ! colspan="2" | Payload to [[Geostationary orbit|GEO]] | Not designed for GEO |}
====Three stage version (Zenit-3SL)==== {| class="wikitable" |- ! colspan="2" | Payload to LEO | 6,100 kg, 3rd stage structural limitation |- ! colspan="2" | Payload to [[Medium Earth orbit|MEO]] | 3,965 kg (10,000 km, 45°) |- ! colspan="2" | Payload to GEO | 1840 kg |- ! colspan="2" | Payload to [[Geostationary transfer orbit|GTO]] | 5,250 kg (upgraded to 6,000+ kg)<!--Spaceway-1 launch on Apr. 26, 2005--> |}
== Launches == {{Main|List of Zenit launches}}
== See also == * [[Comparison of orbital launcher families]] * [[Tsyklon-4]] * [[State Space Agency of Ukraine]]
== References == {{reflist}}
==External links== {{Commons category|Zenit (rocket)}} * [http://www.boris-lux.de/04_types/61_lv/sp_ru/14_zen/spze.php Zenit Family] * [https://web.archive.org/web/20061018183306/http://www.astronautix.com/lvs/zenit3sl.htm Information at Encyclopedia Astronautica] * [https://web.archive.org/web/20070927012634/http://www.nkau.gov.ua/nsau/catalogNEW.nsf/0/EFB7A4C2121BE0F6C2256E8B0044EBA8?OpenDocument&Lang=E Information at National Space Agency of Ukraine] * [http://www.buran-energia.com/energia/zenith-zenit-desc.php Information at Buran web site] * [https://web.archive.org/web/20061029193722/http://www.orbireport.com/Launchers/Zenit_3SL/ Information at Orbital Report News Agency]
{{Rocket families}} {{Ukrainian launch vehicles}} {{Russian launch vehicles}} {{Expendable launch systems}} {{RD-170 rocket engine family}}
{{DEFAULTSORT:Zenit (Rocket Family)}} [[Category:Zenit (rocket family)| ]] [[Category:Rocket families]] [[Category:Space launch vehicles of Ukraine]] [[Category:Expendable space launch systems]] [[Category:Yuzhmash space launch vehicles]]