Minotaur I

Minotaur I

Minotaur I with NFIRE at MARS
Function	Small expendable launch system
Manufacturer	Orbital Sciences
Country of origin	United States
Size
Height	19.21 metres (63.0 ft)
Diameter	1.67 metres (5 ft 6 in)
Mass	36,200 kilograms (79,800 lb)
Stages	4 or 5
Capacity
Payload to LEO	580 kilograms (1,280 lb)
Payload to SSO	331 kilograms (730 lb)
Launch history
Status	Active
Launch sites	Vandenberg SLC-8 MARS LP-0B
Total launches	11
Successes	11
First flight	27 January 2000
First stage - M55A1
Engines	1 Solid
Thrust	935 kilonewtons (210,000 lbf)
Fuel	Solid
Second stage - SR19
Engines	1 Solid
Thrust	268 kilonewtons (60,000 lbf)
Fuel	Solid
Third stage - Orion 50XL
Engines	1 Solid
Thrust	118.2 kilonewtons (26,600 lbf)
Burn time	74 seconds
Fuel	Solid
Fourth stage - Orion 38
Engines	1 Solid
Thrust	34.8 kilonewtons (7,800 lbf)
Burn time	68 seconds
Fuel	Solid

The Minotaur I, or just Minotaur is an American expendable launch system derived from the Minuteman II missile. It is used to launch small satellites for the US Government, and is a member of the Minotaur family of rockets produced by Orbital Sciences Corporation.

Minotaur I rockets consist of the M55A1 first stage and SR19 second stage of a decommissioned Minuteman missile. The Orion 50XL and Orion 38, from the Pegasus rocket, are used as third and fourth stages. A HAPS (Hydrazine Auxiliary Propulsion System) upper stage can also be flown if greater precision is needed, or the rocket needs to be able to manoeuvre to deploy multiple payloads. It can place up to 580 kilograms (1,280 lb) of payload into a 185-kilometer (115 mi) low Earth orbit at 28.5 degrees of inclination.

There have been eleven launches of the Minotaur I, all successful. Initially Minotaur I launches were conducted from Space Launch Complex 8 at the Vandenberg Air Force Base. Starting with the launch of TacSat-2 in December 2006, launches have also been conducted from Pad 0B at the Mid-Atlantic Regional Spaceport on Wallops Island.