Zenit-3SL

Zenit-3SL
Function	Carrier rocket
Manufacturer	Yuzhmash(Zenit) RKK Energia(Block-DM) Boeing(fairing)
Country of origin	Ukraine
Size
Height	59.6 metres (196 ft)
Diameter	3.9 metres (13 ft)
Mass	462,200 kilograms (1,019,000 lb)
Stages	Three
Capacity
Payload toGTO
Mass	6,160 kilograms (13,580 lb)
Associated rockets
Family	Zenit
Derivative work	Zenit-3SLB
Launch history
Status	Retired
Launch sites	Ocean Odyssey
Total launches	36
Success(es)	32
Failure(s)	3
Partial failure(s)	1
First flight	28 March 1999 (test flight)
Last flight	26 May 2014 (Eutelsat 3B)
First stage
Powered by	1RD-171
Maximum thrust	8,180 kilonewtons (1,840,000 lbf)
Specific impulse	337 sec
Burn time	150 seconds
Propellant	RP-1/LOX
Second stage
Powered by	1RD-120 1RD-8
Maximum thrust	912 kilonewtons (205,000 lbf) 79.5 kilonewtons (17,900 lbf)
Specific impulse	349 sec
Burn time	315 seconds
Propellant	RP-1/LOX
Third stage –Block DM-SL
Powered by	1RD-58M
Maximum thrust	84.9 kilonewtons (19,100 lbf)
Specific impulse	352 sec
Burn time	650 seconds
Propellant	RP-1/LOX

TheZenit-3SLwas anexpendablecarrier rocketoperated bySea Launch.First flown in 1999,it was launched 36 times, with three failures and one partial failure. It was a member of theZenitfamily of rockets, and is built by theYuzhnoye Design Bureau.RKK Energiaproduced theBlock DM-SLupper stage,whilst thepayload fairingwas produced byBoeing.Launches were conducted from theOcean Odysseyplatform anchored on theequatorin thePacific Ocean,at a point with 154°Wlongitude,about 370 kilometres east ofKiritimati.

The Zenit-3SL design began in the late 1980s as the Zenit-3, a proposed replacement for theProton-K,which would have used aZenit-2rocket with aBlock Dupper stage. This proposal was shelved after thedissolutionof theSoviet Union,as Russia inherited the space programme, however the Zenit was manufactured inUkrainian SSR.Boeing became involved in the programme in 1994. The design was subsequently modified, with a modified version of theBlock DMreplacing the Block D.

Sea Launch integrated the rockets inCalifornia,and transfers them to Odyssey via theSea Launch Commanderfor transportation to the launch site. Once at the launch site, the rocket was erected on the platform, and a three-day countdown was initiated. The countdown was fully automated,and personnel were evacuated from the launch platform toCommanderprior to launch.

Zenit-3SL launches predominantly carriedcommunications satellitesintogeosynchronous transfer orbits.As of 2009, the only payload to be launched by a Zenit-3SL that was not a communications satellite was aDemoSat,on the maiden flight. The only launch to be conducted to an orbit other than GTO was that ofICO F-1,which was intended to be placed intomedium Earth orbit,however the rocket failed to reach orbit.

Reliability

Of thirty-six rockets launched, three failed, with a fourth placing its payload into an incorrect, but recoverable orbit. The first failure occurred during the third flight, on 12 March 2000, when a software error resulted in the premature cutoff of the second stage, leaving theICO F-1satellite unable to reach orbit.

On 29 June 2004, during the launch ofApstar 5,the upper stage shut down 54 seconds early due to a wiring fault,leaving the satellite in a lower than planned orbit. The spacecraft raised itself to the correct orbit by means of its onboard manoeuvring engines, at the expense of fuel intended for stationkeeping once in the correctorbit.

On 30 January 2007, a Zenit-3SL exploded on the launch pad after an engine failure caused by debris in theturbopump.The payload on that flight was theNSS-8communications satelliteforSES New Skies.This caused a considerable amount of downtime whilst damage to the launch platform was repaired.

On 1 February 2013, during the launch of Intelsat-27, a Zenit-3SL launch vehicle suffered a premature engine shutdown, as the rocket strayed from its lift-off trajectory, plunging into the Pacific Ocean shortly after launch.

See also

• List of software bugs