Antares (rocket)

Antares (rocket)
source
Name	Antares
Manufacturer	Northrop Grumman Innovation Systems; Orbital Sciences Corporation; Aerojet Rocketdyne
Country	United States
Height	42 m
Diameter	3.9 m
Mass	290,000 kg
Status	Operational (as of 2026)
First launch	2013-04-21
Payload to LEO	8,000 kg (typical)

Antares (rocket) Antares is an American medium-class expendable launch vehicle developed to provide orbital cargo delivery and commercial launch services for the United States and international customers. Originating from a partnership between Orbital Sciences Corporation and later Northrop Grumman, Antares has supported resupply for the International Space Station, commercial satellite deployments, and technology demonstration missions. The vehicle integrates propulsion heritage from Yuzhmash and propulsion upgrades from Aerojet Rocketdyne, and it has flown from Wallops Flight Facility under oversight by NASA and commercial providers.

Development

Antares traces its roots to the early 2000s when Orbital Sciences Corporation pursued a medium-lift launcher to serve the growing commercial and government launch market alongside vehicles from SpaceX, United Launch Alliance, and Arianespace. The program formalized under the Commercial Resupply Services (CRS) procurement with NASA for ISS logistics alongside contracts awarded to SpaceX. Initial engineering and flight-test programs involved partners such as Yuzhmash for the first stage core and AJ26 engines, while avionics, structures, and integration were managed by Orbital at facilities in Dulles, Virginia and Wallops Island, Virginia. Following the 2014 mishap, the program moved to engine and supplier changes that brought in Aerojet Rocketdyne for RD-181 engines and later corporate transitions integrated the effort under Northrop Grumman after its acquisition of Orbital. Development milestones included flight tests, safety reviews by NASA and the Federal Aviation Administration, and requalification flights to restore commercial and government manifest confidence.

Design and specifications

Antares employs a two-stage configuration with an optional third stage for higher-energy missions and interplanetary trajectories. The first stage uses a liquid-fueled core derived from Zenit heritage supplied originally by Yuzhmash, with twin or upgraded kerosene/LOX engines depending on variant; those engines include the Russian-built AJ26 (modified NK-33), later replaced by RD-181 engines produced by Energomash and licensed to Aerojet Rocketdyne. The second stage is a solid or liquid upper stage produced by contractors including Thiokol/Northrop Grumman for solid motors and Aerojet Rocketdyne for liquid bi-propellant variants. Vehicle avionics and flight software trace lineage to Orbital's prior designs used on the Pegasus and Minotaur families, incorporating inertial navigation systems, telemetry suites, and flight termination systems certified by the FAA Office of Commercial Space Transportation.

Key dimensions and performance metrics include lift capability to low Earth orbit in the range typical for medium-class rockets, a core diameter compatible with transport logistics via East Coast facilities, and modular interfaces to support cargoed pressurized modules such as Cygnus and secondary payload dispensers compatible with CubeSat standards. Structural materials and manufacturing involved partners like ATK and Kaiser Aerospace for structures and Honeywell for avionics.

Launch history

Antares made its maiden flight in April 2013 from Wallops Flight Facility's Pad 0A, following pad refurbishment historically used for suborbital and sounding-rocket activity. Early manifest flights delivered test payloads and demonstrated insertion accuracy for low Earth orbit rendezvous tasks. In October 2014 an Antares vehicle experienced a catastrophic failure shortly after liftoff, prompting an extended investigation by a mishap board led by representatives from NASA, Orbital, and independent aerospace authorities; the failure traced to AJ26 engine issues and led to a temporary grounding and supplier change. Return-to-flight occurred after the introduction of RD-181 engines, culminating in successful CRS missions that restored operational cadence. Subsequent launches have supported ISS resupply, commercial satellites, and technology demonstrators, with flight rates adjusted for contract demands with NASA and commercial customers such as Sierra Nevada Corporation and academic payloads from institutions like Massachusetts Institute of Technology and University of Maryland.

Payloads and missions

Antares predominantly serves as the launch vehicle for the Cygnus spacecraft under multiple CRS contract iterations, delivering pressurized cargo, science experiments, and spare hardware to the International Space Station. Secondary mission profiles include launching free-flying satellites for telecommunications firms, Earth-observation companies such as Planet Labs, and defense-related payloads coordinated with United States Space Force mission partners. Technology demonstration missions have included platforms from NASA Ames Research Center, universities including Cornell University and Stanford University, and industry partners demonstrating propulsion, avionics, and small-satellite deployment mechanisms. Antares has also carried CubeSats and microsatellites integrated via deployers provided by organizations such as NASA Goddard Space Flight Center and California Polytechnic State University.

Ground operations and launch facilities

Antares operates primarily from Pad 0A at the Mid-Atlantic Regional Spaceport (MARS) located within the Wallops Flight Facility on Wallops Island, Virginia. Ground operations involve vehicle integration in processing facilities adjacent to the pad, payload encapsulation in cleanrooms managed by Orbital/NGIS and oversight by NASA payload officers. Range safety, telemetry, and tracking support are provided by the Wallops Range infrastructure and coordination with the Federal Aviation Administration and Department of Defense for airspace and maritime hazard mitigation. Logistics for propellant loading, hazardous operations, and launch countdown management follow procedures established with contractors including Aerojet Rocketdyne and Northrop Grumman Technical Services, while environmental and wildlife management at Wallops coordinates with agencies such as the Virginia Department of Environmental Quality and local authorities.

Category:Orbital Sciences Corporation rockets Category:Northrop Grumman rockets Category:Expendable space launch systems