Rokot

Rockot (Rokot)

Function	Orbital carrier rocket
Manufacturer	Eurockot Launch Services
Country of origin	Soviet Union
Size
Height	29 metres (95 ft)
Diameter	2.5 metres (8 ft 2 in)
Mass	107,000 kilograms (236,000 lb)
Stages	3
Capacity
Payload to LEO	1,950 kilograms (4,300 lb)
Payload to SSO	1,200 kilograms (2,600 lb)
Launch history
Status	Active
Launch sites	Baikonur 175/1 (inactive) Plesetsk 133/3
Total launches	27
Successes	25
Failures	2
First flight	20 November 1990 26 December 1994 (orbital)
First Stage
Diameter	2.5 m (8.2 ft)[1]
Engines	3 RD-0233 (15D95) 1 RD-0234(15D96)[2][3]
Thrust	2,080 kN (470,000 lbf)[4][5]
Specific impulse	310s[4]
Burn time	120 seconds
Fuel	N2O4/UDMH
Second Stage
Diameter	2.5 m (8.2 ft)[1]
Engines	1 RD-0235 (15D113) 1 RD-0236 (15D114)[2][3]
Thrust	255.76 kN (57,500 lbf)[6][7]
Specific impulse	310s[6]
Burn time	180 seconds
Fuel	N2O4/UDMH
Third Stage - Briz-KM
Engines	1 S5.98M
Thrust	19.6 kilonewtons (4,400 lbf)
Specific impulse	325 sec
Burn time	1,000 seconds
Fuel	N2O4/UDMH

The Rokot (Russian: Рокот meaning Rumble), also transliterated Rockot, is a Russian space launch vehicle that can launch a payload of 1,950 kilograms into a 200 kilometre high Earth orbit with 63° inclination. It is a derivative of the UR-100N (SS-19 Stiletto) intercontinental ballistic missile (ICBM), supplied and operated by Eurockot Launch Services. The first launches started in the 1990s from Baikonur Cosmodrome out of a silo. Later commercial launches commenced from Plesetsk Cosmodrome using a launch ramp specially rebuilt from one for the Kosmos-3M rocket. The cost of the launcher itself was about 15 million in 1999;^[8][9] Eurockot last contract with ESA for launching Swarm in September 2013 is worth of €27.1 million ($36 million).^[10]

Specifications

Rokot's total mass is 107 tonnes, its length 29 metres and its maximum diameter 2.5 metres. The liquid-fueled rocket comprises three stages. The lower two are based on the Soviet UR-100N ICBM; the first stage uses an RD-244 engine, while the second stage uses an RD-235. The third stage is a Briz-KM (Russian: Бриз-КМ meaning Breeze-KM), which has a mass of about 6 tonnes when fuelled, and is capable of flying for 7 hours and reigniting its engine six times during flight, allowing different satellites to be placed into different orbits. All stages use UDMH (unsymmetrical Dimethylhydrazine) as fuel and dinitrogen tetroxide as oxidiser. The Strela is a similar rocket, also based on the SS-19.^[8]

History

The first suborbital test launch succeeded on 20 November 1990 in Baikonur Cosmodrome. On 26 December 1994 Rokot brought its first satellite into Earth orbit. In 1995, Khrunichev State Research and Production Space Center formed a company with German DaimlerBenz Aerospace to market Rokot launches for commercial use. Later, the company was renamed to Eurockot Launch Services. Eurockot bought 45 Rokots from the Russian strategic missile forces to build its inventory. In 2000, Eurokot was partly bought by the German company Astrium GmbH, a shareholder of Arianespace. Astrium now holds 51% of Eurockot's shares, while Khrunichev holds 49%.^[8]

Although there are several silos in Baikonour capable of launching Rokots, it was decided to build an open, non-siloed launch pad at Plesetsk Cosmodrome instead. This is because of concerns that the amount of noise generated during a silo-based launch would damage satellites. In the new pad, Rokot is wheeled up to the structure in a vertical position, and then embraced by its launch tower. The payload is lifted by a crane and placed on top of the bottom two stages. The procedure is in contrast to other Russian launchers, which had traditionally been assembled horizontally and then transferred to the launch site via railways. The first launch from Plesetsk took place on 16 May 2000.^[8]

After 6 entirely successful launches, a launch failure occurred on 8 October 2005, leading to the loss of the European Space Agency's Cryosat spacecraft. The launch vehicle 2nd stage main engine was not shut down properly, resulting in a catastrophic failure and automatic termination of the launch mission by the on-board computer. The payload was lost. After the failed CryoSat launch, all Rokot launches were suspended until the failure was identified. The root cause was unambiguously identified; it was a failure in programming of the Briz-KM (which was contracted to the company JSC "Khartron"). The failure of this high-profile mission led to major reforms in Khrunichev: the director of the company Alexander Medvedev was dismissed, new launch procedures were introduced, the lines of management were straightened out to catch errors and the new Khrunichev chief, Viktor Nesterov, was required to report directly to the head of the Russian Space Agency, Anatoli Perminov.^[8] Corrective measures for Rokot's return-to-flight were implemented for the South Korean Kompsat-2 earth observation satellite launch which took place successfully on 28 July 2006. The Korean side reportedly praised the level of service they received, encouraging the Rokot team to rebuild its order book.^[8]

Another launch failure occurred in February 2011, when a Briz-KM malfunction^[11] resulted in the Geo-IK-2 No.11 satellite being placed into a lower orbit than planned.

Launch table

Planned launches

See also

• Comparison of orbital launchers families
• Strela

References

External links

Wikimedia Commons has media related to Rockot.

• www.eurockot.com Website of Eurockot Launch Service Provider
• www.russianspaceweb.com/rockot.html Rockot history
• Space.com article on CryoSat launch failure