Model of Fregat atMAKS Airshow, 2013 | |
| Manufacturer | NPO Lavochkin |
|---|---|
| Country of origin | Russia |
| Used on | Current:Soyuz-2 Retired:Soyuz-FG,Soyuz-ST,Soyuz-U,Zenit-3F |
| Launch history | |
| Status | Active |
| Total launches | 114 |
| Successes (stage only) | 111 |
| Failed | 2 |
| Other | 1 (partial failure) |
| First flight | 2 February 2000 |
| General characteristics[1] | |
| Height |
|
| Diameter |
|
| Empty mass |
|
| Gross mass |
|
| Propellant mass |
|
| Powered by | 1 × S5.92 |
| Maximum thrust | High: 19.85 kN (4,460 lbf) Low: 13.93 kN (3,130 lbf) |
| Specific impulse | High: 333.2 s (3.268 km/s) Low: 320 s (3.1 km/s) |
| Burn time | Up to 1,350 seconds (up to 7 starts) |
| Propellant | N2O4 / UDMH |
Fregat (Russian:Фрегат,lit. 'frigate') is anupper stage developed byNPO Lavochkin for universal compatibility with a wide range ofmedium- andheavy-lift launch vehicles. Fregat has been used primarily withSoyuz andZenit rockets, and entered operational service in February 2000.
Fregat uses aliquid-propellant engine burningunsymmetrical dimethylhydrazine (UDMH) fuel anddinitrogen tetroxide (N2O4) oxidizer, a pair ofhypergolic propellants that ignite on contact. With a success rate of 97.3%, including two failures and one partial failure, Fregat is among the most reliable upper stages in operation. It has deployed more than 300 payloads into a variety of orbits and is capable of placing three or more spacecraft into distinct orbits during a single mission, owing to its ability to restart up to seven times and operate for a total burn duration of up to 1,350 seconds.
The Fregat upper stage is a versatile and autonomous vehicle designed to inject large payloads into a range of orbits, includinglow,medium, andgeosynchronous. Additionally, it serves as an escape stage for sending space probes on interplanetary missions, such as theVenus Express andMars Express.
Developed by NPO Lavochkin in the 1990s, the Fregat features six spherical tanks—four for propellants and two for avionics—arranged in a circle. Its main engine is centrally positioned, allowing for a compact design with a diameter larger than its height. Structural support is provided by eight struts passing through the tanks, which also transfer thrust loads to the launcher. Fregat operates independently from the lower stages of its launch vehicle, with its own guidance, navigation, attitude control, tracking, and telemetry systems.[2]
The Fregat’s design was largely based on thespacecraft bus used in the SovietPhobos program of the late 1980s, itself based on the architecture used for the Soviet lunar probes developed at NPO Lavochkin in the 1960s.[3] Fregat also integrated several flight-proven subsystems and components from previous spacecraft and rockets. This approach ensured high reliability and accelerated development. Fregat was flight-qualified in February 2000 and successfully completed four missions that same year.[4]
Currently used as the fourth stage on Soyuz launch vehicles, the Fregat’sS5.92 engine is capable of up to 25 ignitions,[3] with seven demonstrated during flight. This allows it to execute complex mission profiles that would be impossible for the launch vehicle alone.[5] The stage provides both three-axis and spin stabilization for spacecraft payloads.[6] Fregat uses storable, hypergolic propellants—unsymmetrical dimethylhydrazine (UDMH) as fuel anddinitrogen tetroxide (N2O4, also called NTO or amyl) as the oxidizer, which ignite spontaneously upon contact. To date, Fregat has successfully deployed over 300 payloads into various orbits and remains the only upper stage capable of placing payloads into three or more distinct orbits in a single launch.[7]
As of 2018[update], adding a Fregat upper stage to a Soyuz-2 launch costs aboutUS$13.5 million.[8][9]
| № | Date | Number | Modification | Mission | Launch vehicle | Payload | Result |
|---|---|---|---|---|---|---|---|
| 1 | 2000/02/09 | 1001 | Fregat | ST07 | Soyuz-U | Success | |
| 2 | 2000/03/20 | 1002 | Fregat | ST08 | Soyuz-U | Success | |
| 3 | 2000/07/16 | 1003 | Fregat | ST09 | Soyuz-U | Success | |
| 4 | 2000/08/09 | 1004 | Fregat | ST10 | Soyuz-U | Success | |
| 5 | 2003/06/02 | 1005 | Fregat | ST11 | Soyuz-FG | Success | |
| 6 | 2003/12/27 | 1006 | Fregat | ST12 | Soyuz-FG | Success | |
| 7 | 2005/08/13 | 1007 | Fregat | ST13 | Soyuz-FG | Success | |
| 8 | 2005/11/09 | 1010 | Fregat | ST14 | Soyuz-FG | Success | |
| 9 | 2005/12/28 | 1009 | Fregat | ST15 | Soyuz-FG | Success | |
| 10 | 2006/10/19 | 1011 | Fregat | ST16 | Soyuz-2.1a | Success | |
| 11 | 2006/12/24 | 1012 | Fregat | – | Soyuz-2.1a | Success | |
| 12 | 2006/12/27 | 1013 | Fregat | ST17 | Soyuz-2.1b | Success | |
| 13 | 2007/05/29 | 1016 | Fregat | ST18 | Soyuz-FG | Success | |
| 14 | 2007/10/20 | 1015 | Fregat | ST19 | Soyuz-FG | Success | |
| 15 | 2007/12/14 | 1015-2 | Fregat | ST20 | Soyuz-FG | Success | |
| 16 | 2008/04/26 | 1008 | Fregat | ST21 | Soyuz-FG | Success | |
| 17 | 2009/05/21 | 1018 | Fregat | – | Soyuz-2.1a | Success | |
| 18 | 2009/09/17 | 1014 | Fregat | – | Soyuz-2.1b | Success | |
| 19 | 2010/10/19 | 1023 | Fregat-M | ST22 | Soyuz-2.1a | Success | |
| 20 | 2010/11/02 | 1022 | Fregat-M | – | Soyuz-2.1a | Success | |
| 21 | 2011/01/20 | 2001 | Fregat-SB | – | Zenith-3SLBF | Success | |
| 22 | 2011/02/26 | 1035 | Fregat-M | – | Soyuz-2.1b | Success | |
| 23 | 2011/07/13 | 1024 | Fregat-M | ST23 | Soyuz-2.1a | Success | |
| 24 | 2011/07/18 | 2002 | Fregat-SB | – | Zenith-3SLBF | Success | |
| 25 | 2011/10/02 | 1045 | Fregat-M | – | Soyuz-2.1b | Success | |
| 26 | 2011/10/21 | 1030 | Fregat-MT | VS01 | Soyuz-ST-B | Success | |
| 27 | 2011/11/28 | 1046 | Fregat-M | – | Soyuz-2.1b | Success | |
| 28 | 2011/12/17 | 1021 | Fregat | VS02 | Soyuz-ST-A | Success | |
| 29 | 2011/12/23 | 1042 | Fregat-M | – | Soyuz-2.1b | Success | |
| 30 | 2011/12/28 | 1027 | Fregat-M | ST24 | Soyuz-2.1a | Success | |
| 31 | 2012/07/22 | 1019 | Fregat | – | Soyuz-FG | Success | |
| 32 | 2012/09/17 | 1037 | Fregat-M | ST25 | Soyuz-2.1a | Success | |
| 33 | 2012/10/12 | 1031 | Fregat-MT | VS03 | Soyuz-ST-B | Success | |
| 34 | 2012/11/14 | 1034 | Fregat-M | – | Soyuz-2.1a | Success | |
| 35 | 2012/12/02 | 1020 | Fregat | VS04 | Soyuz-ST-A | Success | |
| 36 | 2013/02/06 | 1029 | Fregat-M | ST26 | Soyuz-2.1a | Success | |
| 37 | 2013/04/26 | 1047 | Fregat-M | – | Soyuz-2.1b | Success | |
| 38 | 2013/06/25 | 1041 | Fregat-MT | VS05 | Soyuz-ST-B | Success | |
| 39 | 2013/12/19 | 1040 | Fregat-MT | VS06 | Soyuz-ST-B | Success | |
| 40 | 2014/03/23 | 112-01 | Fregat-M | – | Soyuz-2.1b | Success | |
| 41 | 2014/04/03 | 1038 | Fregat-M | VS07 | Soyuz-ST-A | Success | |
| 42 | 2014/06/14 | 112-02 | Fregat-M | – | Soyuz-2.1b | Success | |
| 43 | 2014/07/08 | 1025 | Fregat-M | – | Soyuz-2.1b | Success | |
| 44 | 2014/07/10 | 1032 | Fregat-MT | VS08 | Soyuz-ST-B | Success | |
| 45 | 2014/08/22 | 1039 | Fregat-MT | VS09 | Soyuz-ST-B | Failure | |
| 46 | 2014/10/30 | 1026 | Fregat-M | – | Soyuz-2.1a | Success | |
| 47 | 2014/11/30 | 1044 | Fregat-M | – | Soyuz-2.1b | Success | |
| 48 | 2014/12/18 | 133-01 | Fregat-MT | VS10 | Soyuz-ST-B | Success | |
| 49 | 2015/03/27 | 133-02 | Fregat-MT | VS11 | Soyuz-ST-B | Success | |
| 50 | 2015/09/11 | 133-03 | Fregat-MT | VS12 | Soyuz-ST-B | Success | |
| 51 | 2015/11/17 | 1033 | Fregat-M | – | Soyuz-2.1b | Success | |
| 52 | 2015/12/11 | 2004 | Fregat-SB | – | Zenith-3SLBF | Success | |
| 53 | 2015/12/17 | 133-04 | Fregat-MT | VS13 | Soyuz-ST-B | Success | |
| 54 | 2016/02/07 | 112-03 | Fregat-MT | – | Soyuz-2.1b | Success | |
| 55 | 2016/04/25 | 133-08 | Fregat-M | VS14 | Soyuz-ST-A | Success | |
| 56 | 2016/05/24 | 133-05 | Fregat-MT | VS15 | Soyuz-ST-B | Success | |
| 57 | 2016/05/29 | 112-04 | Fregat-M | – | Soyuz-2.1b | Success | |
| 58 | 2017/01/28 | 133-07 | Fregat-MT | VS16 | Soyuz-ST-B | Success | |
| 59 | 2017/05/18 | 133-09 | Fregat-M | VS17 | Soyuz-ST-A | Success | |
| 60 | 2017/05/25 | 111–301 | Fregat-M | – | Soyuz-2.1b | Success | |
| 61 | 2017/07/14 | 122-02 | Fregat-M | – | Soyuz-2.1a | Partial failure | |
| 62 | 2017/09/22 | 112-05 | Fregat-M | – | Soyuz-2.1b | Success | |
| 63 | 2017/11/28 | Fregat-M | – | Soyuz-2.1b | Failure | ||
| 64 | 2017/12/26 | 2006 | Fregat-SB | – | Zenith-3SLBF | Success | |
| 65 | 2018/02/01 | 122-03 | Fregat-M | – | Soyuz-2.1a | Success | |
| 66 | 2018/03/09 | 133-06 | Fregat-MT | VS18 | Soyuz-ST-B | Success | |
| 67 | 2018/06/16 | 112-06 | Fregat-M | – | Soyuz-2.1b | Success | |
| 68 | 2018/11/03 | 112-08 | Fregat-M | – | Soyuz-2.1b | Success | |
| 69 | 2018/11/07 | 133-14 | Fregat-M | VS19 | Soyuz-ST-B | Success | |
| 70 | 2018/12/19 | 133-10 | Fregat-M | VS20 | Soyuz-ST-B | Success | |
| 71 | 2018/12/27 | 122-06 | Fregat-M | – | Soyuz-2.1a | Success | |
| 72 | 2019/02/21 | 112-07 | Fregat-M | – | Soyuz-2.1b | Success | |
| 73 | 2019/02/27 | 133-15 | Fregat-M | VS21 | Soyuz-ST-B | Success | |
| 74 | 2019/04/04 | 133-17 | Fregat-MT | VS22 | Soyuz-ST-B | Success | |
| 75 | 2019/05/27 | 112-09 | Fregat-M | – | Soyuz-2.1b | Success | |
| 76 | 2019/07/05 | 122-04 | Fregat-M | – | Soyuz-2.1b | Success | |
| 77 | 2019/07/30 | Fregat-M | – | Soyuz-2.1a | Success | ||
| 78 | 2019/09/26 | Fregat-M | – | Soyuz-2.1b | Success | ||
| 79 | 2019/12/11 | 112-10 | Fregat-M | – | Soyuz-2.1b | Success | |
| 80 | 2019/12/18 | Fregat-M | VS23 | Soyuz-ST-A | Success | ||
| 81 | 2020/02/07 | Fregat-M | ST27 | Soyuz-2.1b | Success | ||
| 82 | 2020/02/20 | Fregat-M | – | Soyuz-2.1a | Success | ||
| 83 | 2020/03/17 | Fregat-M | – | Soyuz-2.1b | Success | ||
| 84 | 2020/03/21 | Fregat-M | ST28 | Soyuz-2.1b | Success | ||
| 85 | 2020/12/29 | Fregat | VS24 | Soyuz ST-A | Success | ||
| 86 | 2021/02/28 | 122-07 | Fregat-M | – | Soyuz-2.1b | Success | |
| 87 | 2021/03/22 | 122-05 | Fregat-M | – | Soyuz-2.1a | Success | |
| 88 | 2021/03/25 | 123-05 | Fregat | ST30 | Soyuz-2.1b | Success | |
| 89 | 2021/04/25 | 123-11 | Fregat | ST31 | Soyuz-2.1b | Success | |
| 90 | 2021/05/28 | 123-10 | Fregat | ST32 | Soyuz-2.1b | Success | |
| 91 | 2021/07/01 | 112-15 | Fregat | ST33 | Soyuz-2.1b | Success | |
| 92 | 2021/08/21 | 123-03 | Fregat | ST34 | Soyuz-2.1b | Success | |
| 93 | 2021/09/14 | 123-05 | Fregat | ST35 | Soyuz-2.1b | Success | |
| 94 | 2021/10/14 | 123-14 | Fregat | ST36 | Soyuz-2.1b | Success | |
| 95 | 2021/11/25 | 111–305 | Fregat | – | Soyuz-2.1b | Success | |
| 96 | 2021/12/05 | 133-13 | Fregat-MT | VS26 | Soyuz ST-B | Success | |
| 97 | 2021/12/27 | 123-04 | Fregat | ST37 | Soyuz-2.1b | Success | |
| 98 | 2022/02/05 | 111–401 | Fregat | – | Soyuz-2.1a | Success | |
| 99 | 2022/02/10 | 133-19 | Fregat-MT | VS27 | Soyuz ST-B | Success | |
| 100 | 2022/03/22 | 111-? | Fregat | – | Soyuz-2.1a | Success | |
| 101 | 2022/07/07 | 112-13 | Fregat | – | Soyuz-2.1b | Success | |
| 102 | 2022/08/09 | 123-06 | Fregat | – | Soyuz-2.1b | Success | |
| 103 | 2022/10/10 | 112-16 | Fregat | – | Soyuz-2.1b | Success | |
| 104 | 2022/10/22 | 142-503 | Fregat | – | Soyuz-2.1b | Success | |
| 105 | 2022/11/02 | 111-306 | Fregat | – | Soyuz-2.1b | Success | |
| 106 | 2022/11/28 | 112-?? | Fregat | – | Soyuz-2.1b | Success | |
| 107 | 2023/05/26 | 142-01 | Fregat | – | Soyuz-2.1a | Success | |
| 108 | 2023/06/27 | 142-02 | Fregat | – | Soyuz-2.1b | Success | |
| 109 | 2023/08/07 | 112-23 | Fregat | – | Soyuz-2.1b | Success | |
| 110 | 2023/08/10 | 122-10 | Fregat | – | Soyuz-2.1b | Success | |
| 111 | 2023/12/16 | 122-11 | Fregat | – | Soyuz-2.1b | Success | |
| 112 | 2024/02/29 | 142-03 | Fregat-M | – | Soyuz-2.1b | Success | |
| 113 | 2024/05/16 | ? | Fregat-M | – | Soyuz-2.1b | Success | |
| 114 | 2024/11/04 | 142-601 | Fregat-M | – | Soyuz-2.1b | Success |
TheArianespace-operated flight of a Fregat MT ended infailure on 22 August 2014 after the vehicle deposited twoEU/ESAGalileo navigation satellites into the wrong orbit. The lift off at 12:27:11 UTC from theSinnamary launch site nearKourou,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.[10]
The Independent Inquiry Board formed to analyze the causes of the "anomaly" announced its definitive conclusions on 7 October 2014 following a meeting at Arianespace headquarters inÉvry, nearParis.[11] 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 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.[12]
Since 22 August 2014, Soyuz ST-B launch vehicles with Fregat-MT upper stages have performed three successful launches, sixGalileo navigation satellites have been inserted into their target orbits in frame ofSoyuz at the Guiana Space Centre ongoing ESA programme.[13][14][15]
In July 2017, a Russian-operated rideshare flight of a Fregat upper stage ended with 9 of 72 small satellites dead-on-orbit.[16]
The Russian-operated flight of a Fregat upper stage ended in failure after the vehicle deposited the upper stage, a Meteor MS-1weather satellite, and 18secondarycubesats back intoEarth's atmosphere due to the first Fregat burn being ignited with the stage in the wrong orientation.[17] 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.[18]
The Fregats did not have enough impulse capability to de-orbit themselves after placing their payload into orbit and so several have remained in orbit asspace debris.
The Fregat-SB upper stage rocket used to launch the RussianSpektr-R satellite into orbit in 2011, broke into multiple pieces on May 8, 2020 creating even more debris than normal.[19]
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.[20]
A version calledFregat-SB can be used withZenit-2SB launch vehicle. 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 kg (790 lb) and contains up to 3,050 kg (6,720 lb) of propellant. The total dry weight of the Fregat-SB (including SBB) is 1,410 kg (3,110 lb) and the maximum propellant carrying capacity is 10,150 kg (22,380 lb).[21]
Fregat-SB was launched for the first time on 20 January 2011, when it lifted theElektro-L weather satellite into geosynchronous orbit.[22]
| Stage | Fregat | Fregat-M | Fregat-MT | Fregat-SB | Fregat-SBU | Fregat-2 |
|---|---|---|---|---|---|---|
| Engine | S5.92 | S5.92 LN (Long Nozzle) | ||||
| Total Launches | 44 | 49 | 17 | 4 | – | – |
| 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 | 1235...874 seconds | 1535...1085 seconds | 1640...1160 seconds | 2310...1635 seconds | 2475...1750 seconds | 2830...2000 seconds |
| 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 |