ManufacturerNPO Lavochkin
Country of originRussia
Used onSoyuz-U (retired), Soyuz-FG (retired), Soyuz-2, Zenit-3F
General characteristics
DiameterFregat/Fregat-M: 3.35 m (11.0 ft)

Fregat-MT: 3.80 m (12.5 ft)}

Fregat-SB: 3.875 m (12.71 ft)}
Length1.5 m (4.9 ft)
Propellant massFregat: 5,250 kg (11,570 lb)

Fregat-M: 5,600 kg (12,300 lb)

Fregat-MT: 7,100 kg (15,700 lb)
Empty massFregat: 930 kg (2,050 lb)

Fregat-M: 980 kg (2,160 lb)

Fregat-MT: 1,050 kg (2,310 lb)
Associated stages
ComparableBriz-M, Briz-KM
Thrust19.85 kilonewtons (4,460 lbf)
Specific impulse333.2 seconds
Burn time1,350 seconds[2]
Launch history
Total launches85
(stage only)
First flight2 February 2000

Fregat (Russian: Фрегат, frigate) is an upper stage developed by NPO Lavochkin in the 1990s, which is used in some Soyuz and Zenit rockets, but is universal and can be used as a part of a medium and heavy class launch vehicles. Fregat became operational in February 2000.[3] Its liquid propellant engine uses UDMH and N2O4. Fregat's success rate is 97,6% (with only 2 failures in 83 launches), which makes it one of the most reliable upper stages in the world. Fregat has been successfully delivered more than 300 payloads into different orbits. It remains the only upper stage in the world that can place its payload into 3 or more different orbits in a single launch.[4]


Fregat upper stage is designed for injecting large payloads into a low, medium-height or high geosynchronous orbit. Fregat is a versatile upper stage, in addition to orbital insertion, it can be used as an escape stage to send modern space probes into interplanetary trajectories (e.g. Venus Express and Mars Express). Fregat stages are currently used as the fourth stage of some Soyuz launch vehicles. The stage can be restarted up to 7 times.[5]

NPO Lavochkin has built many interplanetary probes, and the Fregat stage follows their design traditions. The main part of the stage is six intersecting spheres placed on a single plane, four of which contain propellants. The remaining two contain the control equipment. The main engine is placed between the spheres, so Fregat is a tightly-packed stage with a diameter much larger than its height. A set of eight struts through the tanks provide an attachment point for the payload, and also transfer thrust loads to the launcher. The Fregat stage is independent from lower stages, since it has its own guidance, navigation, attitude control, tracking, and telemetry systems. The Fregat uses storable propellants (UDMH/NTO) and can be restarted up to 7 times in flight – enabling it to carry out complex mission profiles. It can provide three-axis or spin stabilization of the spacecraft payload.[6]

Key features

• Autonomous - carries the whole payload delivery process itself without any assistance from Earth
• Smart - AI of the upper stage is programmed to avoid various emergency situations by its own algorithm
• Precise - provides almost absolute delivery accuracy right into a target orbit, due to its navigation equipment based on Glonass and GPS
• Multiple-start ability - engine can be restarted up to 7 times, which makes possible to ensure optimal delivery or to deliver multiple payloads on different target orbits
• Versatile - fueled tanks are being loaded before installation in launch complex, which makes Fregat compatible to any launch vehicle
• Active lifetime up to 2 days
• Ability to start from four spaceports : Baikonur, Vostochny, Plesetsk, CSG

Fregat upper stage launch statistics

Date Number Modification Mission Launch vehicle Payload Result
1 2000/02/09 1001 Fregat ST07 Soyuz-U Russia Full-size satellite layout,
Russia Inflatable Braking Device
2 2000/03/20 1002 Fregat ST08 Soyuz-U Russia Dumsat Success
3 2000/07/16 1003 Fregat ST09 Soyuz-U European Union Cluster FM6,
European Union Cluster FM7
4 2000/08/09 1004 Fregat ST10 Soyuz-U European Union Cluster FM5,
European Union Cluster FM8
5 2003/06/02 1005 Fregat ST11 Soyuz-FG European Union Mars Express,
European Union Beagle 2
6 2003/12/27 1006 Fregat ST12 Soyuz-FG Israel AMOS-2 Success
7 2005/08/13 1007 Fregat ST13 Soyuz-FG United States Galaxy 14 Success
8 2005/11/09 1010 Fregat ST14 Soyuz-FG European Union Venus Express Success
9 2005/12/28 1009 Fregat ST15 Soyuz-FG European Union GIOVE-A Success
10 2006/10/19 1011 Fregat ST16 Soyuz-2.1a European Union MetOp-A Success
11 2006/12/24 1012 Fregat - Soyuz-2.1a Russia Meridian № 11L Success
12 2006/12/27 1013 Fregat ST17 Soyuz-2.1b European Union COROT Success
13 2007/05/29 1016 Fregat ST18 Soyuz-FG United States Globalstar M065,
United States Globalstar M069,
United States Globalstar M071,
United States Globalstar M072
14 2007/10/20 1015 Fregat ST19 Soyuz-FG United States Globalstar M066,
United States Globalstar M067,
United States Globalstar M068,
United States Globalstar M070
15 2007/12/14 1015-2 Fregat ST20 Soyuz-FG Canada RADARSAT-2 Success
16 2008/04/26 1008 Fregat ST21 Soyuz-FG European Union GIOVE-B Success
17 2009/05/21 1018 Fregat - Soyuz-2.1a Russia Meridian № 12L Success
18 2009/09/17 1014 Fregat - Soyuz-2.1b Russia Meteor-M № 1,
Russia Sterkh,
Russia Universitetsky-Tatyana-2,
Russia BLITS,
India IRIS,
South Africa Sumbandila
19 2010/10/19 1023 Fregat-M ST22 Soyuz-2.1a United States Globalstar M073,
United States Globalstar M074,
United States Globalstar M075,
United States Globalstar M076,
United States Globalstar M077,
United States Globalstar M079
20 2010/11/02 1022 Fregat-M - Soyuz-2.1a Russia Meridian № 13L Success
21 2011/01/20 2001 Fregat-SB - Zenith-3SLBF Russia Elektro-L No.1 Success
22 2011/02/26 1035 Fregat-M - Soyuz-2.1b Russia Glonass-K № 11L Success
24 2011/07/13 1024 Fregat-M ST23 Soyuz-2.1a United States Globalstar M081,
United States Globalstar M083,
United States Globalstar M085,
United States Globalstar M088,
United States Globalstar M089,
United States Globalstar M091
25 2011/07/18 2002 Fregat-SB - Zenith-3SLBF Russia Spektr-R Success
26 2011/10/02 1045 Fregat-M - Soyuz-2.1b Russia Glonass-M № 742 Success
27 2011/10/21 1030 Fregat-MT VS01 Soyuz-ST-B European Union Galileo 1,
 European Union Galileo 2
28 2011/11/28 1046 Fregat-M - Soyuz-2.1b Russia Glonass-M № 746 Success
29 2011/12/17 1021 Fregat VS02 Soyuz-ST-A France Pleiades-1A,
France ELISA W11,
France ELISA E12,
France ELISA W23,
France ELISA E24,
Chile SSOT
30 2011/12/23 1042 Fregat-M - Soyuz-2.1b Russia Meridian № 15L Success
31 2011/12/28 1027 Fregat-M ST24 Soyuz-2.1a United States Globalstar M080,
United States Globalstar M082,
United States Globalstar M084,
United States Globalstar M086,
United States Globalstar M090,
United States Globalstar M092
32 2012/07/22 1019 Fregat - Soyuz-FG Russia Kanopus-V № 1,
Russia Zond-PP,
Belarus BKA,
Canada exactView-1,
Germany TET-1
33 2012/09/17 1037 Fregat-M ST25 Soyuz-2.1a European Union MetOp-B Success
34 2012/10/12 1031 Fregat-MT VS03 Soyuz-ST-B European Union Galileo 3,
European Union Galileo 4
35 2012/11/14 1034 Fregat-M - Soyuz-2.1a Russia Meridian № 16L Success
36 2012/12/02 1020 Fregat VS04 Soyuz-ST-A France Pléiades-1B Success
37 2013/02/06 1029 Fregat-M ST26 Soyuz-2.1a United States Globalstar M078,
United States Globalstar M093,
United States Globalstar M094,
United States Globalstar M095,
United States Globalstar M096,
United States Globalstar M097
38 2013/04/26 1047 Fregat-M - Soyuz-2.1b Russia Glonass-K № 747 Success
39 2013/06/25 1041 Fregat-MT VS05 Soyuz-ST-B United Kingdom O3b FM1,
United Kingdom O3b FM2,
United Kingdom O3b FM4,
United Kingdom O3b FM5
40 2013/12/19 1040 Fregat-MT VS06 Soyuz-ST-B European Union Gaia Success
41 2014/03/23 112-01 Fregat-M - Soyuz-2.1b Russia Glonass-M № 754 Success
42 2014/04/03 1038 Fregat-M VS07 Soyuz-ST-A European Union Sentinel-1A Success
43 2014/06/14 112-02 Fregat-M - Soyuz-2.1b Russia Glonass-M № 755 Success
44 2014/07/08 1025 Fregat-M - Soyuz-2.1b Russia Meteor-M №2,
Russia Vernov,
Russia DX1 [ru],
United Kingdom UKube-1,
United Kingdom TechDemoSat-1,
United States SkySat-2,
Norway AISSat-2
45 2014/07/10 1032 Fregat-MT VS08 Soyuz-ST-B United Kingdom O3b FM3,
United Kingdom O3b FM6,
United Kingdom O3b FM7,
United Kingdom O3b FM8
46 2014/08/22 1039 Fregat-MT VS09 Soyuz-ST-B European Union Galileo 5,
European Union Galileo 6
47 2014/10/30 1026 Fregat-M - Soyuz-2.1a Russia Meridian № 17L Success
48 2014/11/30 1044 Fregat-M - Soyuz-2.1b Russia Glonass-K № 12L Success
49 2014/12/18 133-01 Fregat-MT VS10 Soyuz-ST-B United Kingdom O3b FM9,
United Kingdom O3b FM10,
United Kingdom O3b FM11,
United Kingdom O3b FM12
50 2015/03/27 133-02 Fregat-MT VS11 Soyuz-ST-B European Union Galileo 7,
European Union Galileo 8
51 2015/09/11 133-03 Fregat-MT VS12 Soyuz-ST-B European Union Galileo 9,
European Union Galileo 10
52 2015/11/17 1033 Fregat-M - Soyuz-2.1b Russia EKS № 1 Success
53 2015/12/11 2004 Fregat-SB - Zenith-3SLBF Russia Elektro-L No.2 № 2 Success
54 2015/12/17 133-04 Fregat-MT VS13 Soyuz-ST-B European Union Galileo 11,
European Union Galileo 12
55 2016/02/07 112-03 Fregat-MT - Soyuz-2.1b Russia Glonass-M № 751 Success
56 2016/04/25 133-08 Fregat-M VS14 Soyuz-ST-A European Union Sentinel-1B Success
57 2016/05/24 133-05 Fregat-MT VS15 Soyuz-ST-B European Union Galileo 13,
European Union Galileo 14
58 2016/05/29 112-04 Fregat-M - Soyuz-2.1b Russia Glonass-M № 753 Success
59 2017/01/28 133-07 Fregat-MT VS16 Soyuz-ST-B Spain Hispasat 36W-1 Success
60 2017/05/18 133-09 Fregat-M VS17 Soyuz-ST-A Luxembourg SES-15 Success
61 2017/05/25 111-301 Fregat-M - Soyuz-2.1b Russia Tundra № 2 Success
62 2017/07/14 122-02 Fregat-M - Soyuz-2.1a Russia Kanopus-V-IK,
Russia MKA-N № 1,
Russia MKA-N № 2,
Russia Mayak,
Russia Iskra-MAI-85,
Ecuador Ecuador UTE-YUZGU»,
Germany Flying Laptop,
Germany TechnoSat,
Japan WNISAT-1R,
Norway NorSat-1,
Norway NorSat-2,
United States Flock-2k 1...48,
United States CICERO 1...3,
United States Corvus-BC 1...2,
United States Lemur-2 42...49,
United States NanoACE
63 2017/09/22 112-05 Fregat-M - Soyuz-2.1b Russia Glonass-M № 752 Success
64 2017/11/28 Fregat-M - Soyuz-2.1b Russia Meteor-M №2,
Russia Baumanets-2,
Canada LEO Vantage 2,
Canada Helios-Wire BIU,
Japan IDEA-OSG 1,
Norway AISSat-3,
Germany D-Star One,
Sweden SEAM,
United States Corvus-BC 3,
United States Lemur-2 58...67
65 2017/12/26 2006 Fregat-SB - Zenith-3SLBF Angola Angosat-1 Success
66 2018/02/01 122-03 Fregat-M - Soyuz-2.1a Russia Kanopus-V № 3,
Russia Kanopus-V № 4,
United States Lemur-2 74,
United States Lemur-2 75,
United States Lemur-2 76,
United States Lemur-2 77,
Germany S-Net A,
Germany S-Net B,
Germany S-Net C,
Germany S-Net D,
Germany D-Star One
67 2018/03/09 133-06 Fregat-MT VS18 Soyuz-ST-B United Kingdom O3b FM13,
United Kingdom O3b FM14,
United Kingdom O3b FM15,
United Kingdom O3b FM16
68 2018/06/16 112-06 Fregat-M - Soyuz-2.1b Russia Glonass-M № 756 Success
69 2018/11/03 112-08 Fregat-M - Soyuz-2.1b Russia Glonass-M № 757 Success
70 2018/11/07 133-14 Fregat-M VS19 Soyuz-ST-B Europe MetOp-C Success
71 2018/12/19 133-10 Fregat-M VS20 Soyuz-ST-B France Composante Spatiale Optique Success
72 2018/12/27 122-06 Fregat-M - Soyuz-2.1a Russia Kanopus-V № 5,
Russia Kanopus-V № 6,
Japan GRUS-1,
South Africa ZACube-2,
Spain Lume-1,
United States Flock-3k 1...12,
United States Lemur-2 88...95,
Germany D-Star One iSat,
Germany D-Star One Sparrow,
Germany UWE-4,
Finland ICEYE-Dummy,
Israel SAMSON-Dummy 1...3
73 2019/02/21 112-07 Fregat-M - Soyuz-2.1b Egypt EgyptSat-A Success
74 2019/02/27 133-15 Fregat-M VS21 Soyuz-ST-B United Kingdom OneWeb-0006,
United Kingdom OneWeb-0007,
United Kingdom OneWeb-0008,
United Kingdom OneWeb-0010,
United Kingdom OneWeb-0011,
United Kingdom OneWeb-0012
75 2019/04/04 133-17 Fregat-MT VS22 Soyuz-ST-B United Kingdom O3b FM17,
United Kingdom O3b FM18,
United Kingdom O3b FM19,
United Kingdom O3b FM20
76 2019/05/27 112-09 Fregat-M - Soyuz-2.1b Russia Glonass-M № 758 Success
77 2019/07/05 122-04 Fregat-M - Soyuz-2.1b Russia Meteor-M No.2
Russia Sokrat
Russia VDNH-80
Russia AmurSat
Sweden SEAM-2.0
France MTCube
Germany SONATE
Germany Beesat 9…13
Germany MOVE-IIb
Estonia TTU-101
Ecuador Ecuador-UTE
United States El Camino Real
United StatesLemur-2 100…107
Israel NSLSat-1
Thailand JAISAT-1
Germany LightSat
Czech Republic Lucky-7
Finland ICEYE X4
Finland ICEYE X5
Germany CarboNIX
United Kingdom DoT 1
78 2019/07/30 Fregat-M - Soyuz-2.1a Russia Meridian № 18L Success
79 2019/09/26 Fregat-M - Soyuz-2.1b Russia Tundra № 3 Success
80 2019/12/11 112-10 Fregat-M - Soyuz-2.1b Russia Glonass-M № 759 Success
81 2019/12/18 Fregat-M VS23 Fregat-ST-A Italy COSMO-SkyMed
European Union CHEOPS
France EyeSat
European Union OPS-SAT
82 2020/02/07 Fregat-M ST27 Soyuz-2.1b United Kingdom OneWeb (34 units) Success
83 2020/02/20 Fregat-M - Soyuz-2.1a Russia Meridian № 19L Success
84 2020/03/17 Fregat-M - Soyuz-2.1b Russia Glonass-M №760 Success
85 2020/03/21 Fregat-M ST28 Soyuz-2.1b United Kingdom OneWeb (34 units) Success


August 2014 failure

The Arianespace-operated flight of a Fregat MT ended in failure on 22 August 2014 after the vehicle deposited two EU/ESA Galileo navigation satellites into the wrong orbit. The lift off at 1227 GMT from the Sinnamary launch site near Kourou, French Guiana, appeared to go well. However, a failure was only apparent later when, after the second firing of the Fregat MT upper stage had taken place, the satellites were detected as being in the wrong orbit.[7]

The Independent Inquiry Board formed to analyze the causes of the "anomaly" announced its definitive conclusions on October 7, 2014 following a meeting at Arianespace headquarters in Évry, near Paris.[8]

The failure occurred during the flight of the Fregat fourth stage. It occurred about 35 minutes after liftoff, at the beginning of the ballistic phase preceding the second ignition of this stage.

The scenario that led to an error in the orbital injection of the satellites was precisely reconstructed, as follows:

  • The orbital error resulted from an error in the thrust orientation of the main engine on the Fregat stage during its second powered phase.
  • This orientation error was the result of the loss of inertial reference for the stage.
  • This loss occurred when the stage's inertial system operated outside its authorized operating envelope, an excursion that was caused by the failure of two of Fregat's attitude control thrusters during the preceding ballistic phase.
  • This failure was due to a temporary interruption of the joint hydrazine propellant supply to these thrusters.
  • The interruption in the flow was caused by freezing of the hydrazine.
  • The freezing resulted from the proximity of hydrazine and cold helium feed lines, these lines being connected by the same support structure, which acted as a thermal bridge.
  • Ambiguities in the design documents allowed the installation of this type of thermal "bridge" between the two lines. In fact, such bridges have also been seen on other Fregat stages now under production at NPO Lavochkin.
  • The design ambiguity is the result of not taking into account the relevant thermal transfers during the thermal analyses of the stage system design.

The root cause of the failure of flight VS09 is therefore a shortcoming in the system thermal analysis performed during stage design, and not an operator error during stage assembly.[8][9]

Since August 22, 2014 Soyuz ST-B launch vehicles with Fregat-MT upper stages have performed three successful launches, six Galileo navigation satellites have been inserted into their target orbits in frame of Soyuz at the Guiana Space Centre ongoing ESA programme.[10][11][12]

November 2017 failure

The Russian-operated flight of a Fregat upper stage ended in failure after the vehicle deposited the upper stage, a Meteor MS-1 weather satellite, and 18 secondary cubesats back into Earth's atmosphere due to the first Fregat burn being ignited with the stage in the wrong orientation.[13] The guidance computer on the Soyuz rocket's Fregat upper stage was mis-programmed, causing it to begin an unnecessary turn that left it in the wrong orientation for a critical engine burn required to enter orbit.[14]



Fregat-M/Fregat-MT tanks have ball-shaped additions on the tops of the tanks. These additions increase the load capability of the propellant from 5,350 kilograms (11,790 lb) to 6,640 kilograms (14,640 lb), without causing any other changes to the physical dimensions of the vehicle.[2]


A version called Fregat-SB can be used with Zenit-2SB rocket. This version is a variation of Fregat-M with a block of drop-off tanks ("SBB" or Сбрасываемый Блок Баков in Russian) which makes increased payload capability possible. The torus-shaped SBB weighs 360 kilograms (790 lb) and contains up to 3,050 kilograms (6,720 lb) of propellant. The total dry weight of the Fregat-SB (including SBB) is 1,410 kilograms (3,110 lb) and the maximum propellant carrying capacity is 10,150 kilograms (22,380 lb).[15]

Fregat-SB was launched for the first time on 20 January 2011, when it lifted the Elektro-L weather satellite into geosynchronous orbit.[16]

All versions data

Fregat Upper Stage Family[17]
Stage Fregat Fregat-M Fregat-MT Fregat-SB Fregat-SBU Fregat-2
Engine S5.92 S5.92 l.n. (Long Nozzle)
Total Launches 22 18 8 3 - -
Thrust (Low) 13.73 kN (3,090 lbf) 13.96 kN (3,140 lbf)
Thrust (High) 19.61 kN (4,410 lbf) 20.01 kN (4,500 lbf)
Specific Impulse (Low) 3,168 N*s/kg 3,222 N*s/kg
Specific Impulse (High) 3,207 N*s/kg 3,268 N*s/kg
Propellant (Max) 5,350 kg (11,790 lb) 6,640 kg (14,640 lb) 7,100 kg (15,700 lb) 10,000 kg (22,000 lb) 10,710 kg (23,610 lb) 12,240 kg (26,980 lb)
Burn Time 1,235...874 s 1,535...1,085 s 1,640...1,160 s 2,310...1,635 s 2,475...1,750 s 2,830...2,000 s
Flow Rate 4.3...6.1 kg/s
Total Impulse 16.9...17.2 MN*s 21.4...21.7 MN*s 22.9...23.2 MN*s 32.2...32.7 MN*s 34.5...35.0 MN*s 39.4...40.0 MN*s


  1. ^ "Конструкция разгонного блока "Фрегат"". NPO Lavochkin (in Russian). Archived from the original on 26 December 2015. Retrieved 10 March 2016.
  2. ^ a b "Fregat space tug". RussianSpaceWeb. Retrieved 26 July 2014.
  3. ^
  4. ^
  5. ^
  6. ^
  7. ^ "Archived copy". Archived from the original on 2014-10-13. Retrieved 2014-10-08.CS1 maint: archived copy as title (link)
  8. ^ a b "Soyuz Flight VS09: Independent Inquiry Board announces definitive conclusions concerning the Fregat upper stage anomaly" (Press release). Evry: Arianespace. 8 October 2014. Retrieved 10 April 2016.
  9. ^ "Soyuz Flight VS09: Independent Inquiry Board announces definitive conclusions concerning the Fregat upper stage anomaly - Arianespace".
  10. ^ "Archived copy". Archived from the original on 2016-01-27. Retrieved 2016-01-14.CS1 maint: archived copy as title (link)
  11. ^ "Archived copy". Archived from the original on 2016-03-03. Retrieved 2016-01-14.CS1 maint: archived copy as title (link)
  12. ^
  13. ^ "Russian weather satellite and 18 secondary payloads lost after rocket failure – Spaceflight Now".
  14. ^ "Russian official blames Nov. 28 launch failure on botched software programming – Spaceflight Now". Retrieved 2018-09-18.
  15. ^ "L'étage supérieur Fregat-SB : descriptif technique (in French)". 2012-12-12.
  16. ^ "Russia meteo satellite Electro-L successfully orbited". ITAR-TASS. 2011-01-21. Archived from the original on 2011-01-22.
  17. ^ "NPO Lavochkin's Fregat upper stage, Gallery". Retrieved 2015-08-05.

External links

  • Fregat page on the manufacturer site