Orbital Sciences Admits Refurbished Soviet Engine Probably Made Its Rocket Explode

Giuseppe Macri Tech Editor
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Orbital Sciences — the private space contractor responsible for building a rocket that exploded at launch last week while carrying supplies to the International Space Station — announced this week that a refurbished, decades-old Soviet rocket engine was the likely culprit in the disaster.

“While still preliminary and subject to change, the current evidence strongly suggests that one of the two AJ-26 main engines that powered Antares’ first stage failed about 15 seconds after ignition,” Orbital Sciences CEO David Thompson said during a conference call Wednesday, according to The Verge. “At this time, we believe the failure likely originated in, or directly affected, the turbopump machinery of this engine.” (RELATED: Check Out These Eyewitness Videos Of Orbital Sciences’ Rocket Exploding At Launch)

Orbital’s Aerojet Rocketdyne AJ-26 engines are actually modified and retrofitted Soviet-made NK-33 engines, which were originally built in the late 60s and early 70s by the Moscow-based JSC Kuznetsov. The engines were designed to launch the N1 Russian rocket to the moon.

Aerojet Rocketdyne, a division of the American-based GenCorp Inc, “modernized a gimbal block for thrust vectoring capability, gimbaling feedlines, new wiring harnesses and electrical circuitry, electromechanical valve actuators and instrumentation” on the engines for use in the Antares, according to the company’s website.

The same engine exploded during a ground test at NASA’s Stennis Space Center in Mississippi earlier this May.

Elon Musk, CEO of SpaceX — one of Orbital’s competitors — described Orbital’s rocket as “a joke” for its reliance on Soviet-era engines during an interview two years ago. (RELATED: Elon Musk Called Orbital Sciences’ Rocket ‘A Joke’ Years Before Launch Explosion)

Orbital had been planning to upgrade the Antares’ engines by 2017, but is moving that window forward to 2016 and retiring the AJ-26 altogether.

The same rocket performed without incident on three prior ISS resupply missions, and Orbital plans to fulfill the remainder of its $1.9 billion contract with NASA by purchasing space on competitors’ rockets.

SpaceX, which holds a $1.6 billion NASA contract to resupply the ISS, will launch its fifth mission on Dec. 9.

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