Northrop Grumman Corporation and launch vehicle manufacturer Firefly Aerospace have joined forces to provide an American-built first-stage upgrade for the Antares 330 rocket, so it is no longer reliant on Russian-built RD-181 engines. The Antares 330 will use seven of Firefly’s Miranda engines in lieu of the current pair of RD-181 engines produced by the Energomash firm. The new engines will continue to have Kerosene and Liquid Oxygen (LOx) as their propellants.
The current RD-181 pair of engines on the Antares 230/230+ originally replaced a pair of Ukrainian-built AJ-26 engines – refurbished Yuzhmash-built NK-33 engines originally developed for the N-1 lunar rocket – after an engine test failure and subsequent engine-related launch failure (losing the Cygnus Orb-3 cargo craft).
Although the RD-181 engines appeared to work well Northrop Grumman has been forced to seek out a replacement following the invasion of Ukraine by Russia. The subsequent brutal war, and its related sanctions and countersanctions, led to a halt in the delivery of Russian-built RD-181 engines.
“Through our collaboration, we will first develop a fully domestic version of our Antares rocket, the Antares 330, for Cygnus space station commercial resupply services, followed by an entirely new medium class launch vehicle,” said Scott Lehr, vice president and general manager of launch and missile defence systems at Northrop Grumman.
The stage design uses previously developed composite technology for the first-stage structures and tanks. Northrop Grumman will provide avionics and software, upper-stage structures and a Castor 30XL motor for the second (upper) stage (already used on the Antares 230/230+), as well as vehicle integration and launch-pad operations. The new stage is expected to significantly increase Antares 330’s mass-to-orbit capability from the current payload of 8,000 kg to LEO for the Antares 230+.
Comment by David Todd: Firefly Alpha has yet to make a successful flight, after its maiden flight ended in failure. So, even with different engines, the Firefly Aerospace firm is – as yet – unproven. Still, the new engine solution is likely to be the best one for Northrop Grumman’s Antares 330 first-stage needs. It will work, as long as reliability is achieved and costs are kept low.