Meet the New Engines of the Antares Rocket

For the Antares Return to Flight, Orbital ATK will rely on the Energomash RD-181 rocket motor. It is an all-new engine based on other successful liquid rocket engines Energomash designed and produced. The engines use an oxygen-rich staged combustion cycle that can be throttled, and has a variable mixture ratio for controlling relative flow rates of oxidizer and fuel.

illustration of rocket engine
The Energomash RD-181 is an all new engine based on successful models.

The Antares second stage is powered by a CASTOR 30XL solid rocket motor produced and tested at Orbital ATK facilities in Utah. The CASTOR 30XL is based on the CASTOR 120, used in more than a dozen missions. The OA-5 mission will be the first use of this motor, allowing Antares to significantly increase its payload capability.

text and picture of rocket suspended above people
The CASTOR 30XL solid rocket motor will help boost Cygnus payload capacity.

The Antares 230 rocket for this mission is a two-stage launch vehicle consisting of a liquid-fueled Liquid Oxygen/Refined Petroleum (LOX/RP) first stage powered by two Energomash RD-181s that will burn about 209 seconds. Antares employs a 9.9 m (32.5 ft.) long fairing to protect Cygnus as Antares accelerates through Earth’s atmosphere. It will separate at 250 seconds into flight, after which the second stage will burn about 163 seconds. The Cygnus cargo capsule will reach its initial orbit about 9 minutes after launch.

2 thoughts on “Meet the New Engines of the Antares Rocket”

  1. so, who is a producer of first stage engine for this launch: Energomash (Russia) or Uzhnoye (Ukraine) ?
    a lot of different info in the net about this

    1. The Antares core tank design and design verification is by KB Yuzhnoye (Zenit-derived heritage). The core tank is produced by Yuzhmash. There are two Energomash RD-181
      engines in the first stage.

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