Minotaur-C

Taurus

Taurus 3210 preparing to launch ROCSAT 2 on May 20, 2004.
Function	Orbital launch vehicle
Manufacturer	Orbital Sciences
Country of origin	United States
Size
Height	27.9 m (91.5 ft)
Diameter	2.35 m (7.7 ft)
Mass	73,000 kg (160,000 lb)
Stages	4
Capacity
Payload to LEO	1,320 kg (2,910 lb)
Launch history
Status	Active
Launch sites	Wallops Island LC-576E, Vandenberg AFB Cape Canaveral Kodiak Island
Total launches	9
Success(es)	6
Failure(s)	3
First flight	20:06 GMT, 21/12/89
First stage - Castor 120
Engines	1 solid
Thrust	1,606.6 kN (361,177 lbf)
Specific impulse	286 sec
Burn time	83 seconds
Propellant	Solid
Second stage Taurus-1
Engines	1 solid
Thrust	484.9 kN (109,012 lbf)
Specific impulse	285 sec
Burn time	73 seconds
Propellant	solid
Third stage - Pegasus-2
Engines	1 solid
Thrust	118.2 kN (26,570 lbf)
Specific impulse	292 sec
Burn time	73 seconds
Propellant	solid
Fourth stage - Pegasus-3
Engines	1 solid
Thrust	34.57 kN (7,770 lbf)
Specific impulse	293 sec
Burn time	65 seconds
Propellant	solid

Taurus is a four stage, solid fuel launch vehicle built in the United States by Orbital Sciences Corporation. It is based on the air-launched Pegasus rocket from the same manufacturer. The Taurus rocket is able to carry a payload of around 1,350 kg into a low Earth orbit. First launched in 1994, it has successfully completed six out of a total of nine military and commercial missions. Three of the last four launches have ended in failure, including the February 24, 2009 launch of the Orbiting Carbon Observatory mission and the March 4, 2011 launch of the Glory mission. The failure of the two latest launches resulted in losses totalling $700 million for NASA (not including cost of the rockets themselves).

Stages

The Taurus first stage, a Castor 120 made by ATK (formerly Thiokol), is based on a Peacekeeper ICBM first stage. Stages 2 and 3 are Orion-50s (like the Pegasus-1 but without wings or stabilisers), and stage 4 is an Orion-38, derived from the Pegasus-3.

Numbering system

Different configurations are designated using a four digit code, similar to the numbering system used on Delta rockets. The first digit denotes the type of first stage being used, and whether the second and third stages use a standard or "XL" configuration. The second digit denotes the diameter of the payload fairing. The third digit denotes the type of fourth stage. The fourth digit denotes an optional fifth stage, however as of 2009, this has not been used.

Number	First digit			Second Digit	Third Digit	Fourth Digit
	First stage	Second stage	Third stage	Fairing diameter	Fourth stage	Fifth stage
0	—			—	—	None
1	TU-903	Orion-50ST	Orion-50T	1.60 m (63 in)	Orion-38	—
2	Castor-120	Orion-50ST	Orion-50T	2.34 m (92 in)	—	—
3	Castor-120	Orion-50SXLT	Orion-50XLT	—	Star-37FM	Star-37

List of launches

Flight number	Date	Vehicle type	Payload	Result
1	March 13, 1994	ARPA Taurus	STEP Mission 0 & DARPASAT	Success
2	February 10, 1998	Commercial Taurus, 92" payload fairing and 63" dual payload attach fitting	GFO and ORBCOMM (Satellites 11,12)	Success
3	October 3, 1998	Air Force Taurus Configuration, 63" fairing, Peacekeeper Stage 0	Space Technology Experiment (STEX) for National Reconnaissance Office (NRO)	Success
4	December 20, 1999	Model 2110, 63" fairing, Castor 120 Stage 0	KOMPSAT and ACRIMSAT	Success
5	March 12, 2000	Air Force Taurus Configuration, 63" fairing, Peacekeeper Stage 0	Multispectral Thermal Imager (MTI)	Success
6	September 21, 2001	Model 2110, 63" fairing Castor 120 Stage 0	Orbview-4/QuikTOMS	Failure
7	May 20, 2004	Model 3210, 92" fairing, Castor 120 Stage 0	ROCSAT-2	Success
8	February 24, 2009	Model 3110, 63" fairing Castor 120 Stage 0	Orbiting Carbon Observatory	Failure
9	March 4, 2011	Model 3110, 63" fairing Castor 120 Stage 0	Glory, KySat-1, Hermes, and Explorer-1 [PRIME]	Failure

Launch failures

Orbview launch failure

On September 21, 2001, a Taurus XL rocket failed during launch. Liftoff occurred successfully, but the rocket did not reach orbit.

OCO launch failure

On February 24, 2009, a Taurus XL rocket failed during the launch of the $270m Orbiting Carbon Observatory spacecraft. Liftoff occurred successfully at 09:55 GMT from Vandenberg Air Force Base, but data received at a later stage of the flight suggested that the fairing failed to separate. The rocket did not reach orbit. Launch vehicle and services for OCO are estimated at $54m. NASA canceled a contract to launch a replacement satellite, OCO-2, on a Taurus XL in February 2012.

Glory launch failure

On March 4, 2011, a Taurus XL rocket failed again during the launch of NASA's $424 million Glory climate change monitoring satellite. The reason for the failure was the same as with OCO: the payload fairing failed to separate, although the rocket's manufacturer Orbital Sciences Corporation had spent the last two years trying to fix the problem and had made several design changes to the fairing separation system. The fairing was built by the Vermont Composites company. In total, the last two failures of the Taurus XL have resulted in payload losses worth $700 million. Ronald Grabe, manager of Orbital Sciences Corporation, which also built the Glory satellite itself, said the employees of his companies are "pretty devastated" because of the latest failure.

OBV

Main article: Ground-Based Midcourse Defense

Vehicles similar to Taurus carrier rockets are used as "Orbital Boost Vehicles" for the U.S. Missile Defense Agency's Ground-Based Midcourse Defense system.

See also

• Comparison of orbital launchers families

External links

• Official website