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Athena |
Lockheed
Martin * ATK Thiokol Propulsion * Pratt & Whitney
Athena was developed commercially by Lockheed Martin to address the market for delivering
small spacecraft to LEO. The Athena family includes two small launch vehicles, the
three-stage Athena I (syn.
LMLV-1) and the four-stage Athena II. Both vehicles are made up of solid motors
and a small liquid injection stage, called the Orbit Adjust Module (OAM). The vehicles
are modular, and the Athena II shares all the components of Athena I with the addition of an extra
Castor 120 solid motor. The Athena I preceding version is the
LLV-1, developed by Lockheed
based on a Peacekeeper first-stage.
The Castor 120 is a commercial SRM developed by Thiokol. It is a derivative of the
Peacekeeper ICBM first stage motor TU-902. It has the same diameter as the
PK, but is 35 in. longer to include more propellant. The casing is filament-wound
graphite-epoxy composite, and TVC is provided by a new blowdown hydraulic nozzle
gimbal system.
The Pratt & Whitney's Orbus-21D motor is derived from the Orbus-21 motors used in
the IUS and TOS upper stage for the Titan. For the future missions Lockheed Martin
will upgrade to the Orbus-21G motor, which has a lightweight graphite-epoxy motor
casing in place of the current Kevlar case.
The OAM is a small, monopropellant hydrazine stage that provides precise orbit injection.
Axial propulsion is provided by four small 220 N thrusters around the circumference
of the stage. The OAM is available with four or six propellant tanks. The
tanks are mounted in pairs in an egg-crate frame structure inside the stage.
The standard fairing is the Model 92 (diameter 92 in.) with a 7.6 ft. length.
| Performance | LEO | LPEO | SSO | GTO |
| Athena I | 0.80 | 0.52 | 0.36 | - |
| Athena II | 2.00 | 1.49 | 1.16 | 0.59 |
Lockheed Martin and Alliant Techsystems (ATK)
will attempt to resurrect the long-dormant Athena series of small-satellite launchers
under an arrangement.
The upgraded Athena Ic and Athena IIc rockets will feature the same Castor 120 solid rocket
motors as their predecessors, but use the newly developed Castor 30 motor for their
upper stage. The original Athena vehicles used the Orbus 21D motor built by the
former Chemical Systems Division of United Technologies Corp.
The new Athena vehicles will starting in 2012.