Taurus II

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This article is about the rocket, for the song, see Five Miles Out

Fact sheet
Taurus II
An artist's rendering of the Taurus II at the Mid-Atlantic Regional Spaceport
Function	Medium expendable launch system
Manufacturer	Orbital Sciences
Country of origin	United States
Size
Height	40 m^[1] (131 ft)
Diameter	3.9 m^[2] (12.8 ft)
Mass	~240,000 kg^[3] (530,000 lb)
Stages	2
Capacity
Payload to LEO	5,500 kg ^[4]
Associated Rockets
Comparable	Athena III Delta II
Launch History
Status	Development
Launch sites	Cape Canaveral Pad 0B, MARS
Maiden flight	Scheduled for 2010
Notable payloads	Cygnus

Taurus II is an American medium-capacity expendable launch system, being developed by Orbital Sciences Corporation as an alternative to, and potential replacement for, the United Launch Alliance Delta II. NASA awarded to Orbital a COTS contract to launch cargo missions to the International Space Station. Under this contract, the Taurus II will be used to launch the Cygnus spacecraft. It is scheduled to make its first flight in 2010.^[5] In addition, the vehicle would compete for small-to-medium missions^[6].

1 Development
2 Layout
3 See also
4 References

[edit] Development

Thirteen firms submitted bids; NASA selected five finalists: Andrews Space, Boeing, PlanetSpace, Spacehab, and Orbital Sciences Corporation. On 19 February 2008, NASA announced that Orbital's Taurus II/Cygnus spacecraft had won the COTS cargo launch services contract. They are scheduled to make their first flight together in 2010.^[5] In addition, the vehicle would compete for small-to-medium science and technology-demonstrator missions.

The award is for US$171 million; Orbital expects to invest $150 million in addition, split between $130 million for the booster and $20 million for the spacecraft^[7].

Launch is planned from Wallops Flight Facility, though Orbital engineer Antonio Elias did not rule out later capabilities for launch at Cape Canaveral. A launch from Wallops would reach the International Space Station's orbit as effectively as from the Cape, while being less crowded^[8]^[9]. It is currently planned for the first Cygnus flight to be an unloaded demonstration; the first Cygnus flight may or may not be the first Taurus flight, pending additional bookings.

[edit] Layout

The first stage will be a kerosene/oxygen rocket, powered by two NK-33s (remarketed by Aerojet as the AJ-26). As Orbital has little experience with large liquid stages and LOX propellant, some amount of work will be contracted to NPO Yuzhnoye, designers of the Zenit series. One source claims that the amount will include "main-stage fuel tanks and associated plumbing"^[10]. It appears at this time that the vehicle will share the 3.9 meter diameter of Zenit.

The second stage is a solid, the Castor 30, to be developed by ATK as a derivative of the Castor 120 solid stage. The third stage is a hypergolic stage, to be developed by Orbital as a derivative of prior missions. The hardware will be derived from onboard thruster systems of the OSC Star 2 bus; other elements will use knowledge from the DART mission, of which OSC was the prime contractor^[11]. Exact parameters may change as the vehicle develops.

This hypergolic propulsion system is planned to form the basis of the Cygnus spacecraft. The equipment section will likely be topped by a smaller development of the MPLM for pressurized cargo, and possibly a derivative of the ExPRESS Logistics Carrier for unpressurized cargo. Initial production of pressurized modules will take place in Italy. No reentry and return capabilities are planned so far, but as with the rest of the project, details are still subject to change^[12].