Skip to main content

Orbital says its Soviet engine probably made its rocket explode

Orbital says its Soviet engine probably made its rocket explode


The company will retire its 40-year-old engines after Tuesday's failed launch

Share this story


A decades-old Soviet engine is probably to blame for last week's rocket explosion. Last Tuesday, Orbital Science’s unmanned Antares rocket detonated 15 seconds into launch, injuring no one but destroying thousands of pounds of supplies meant for the International Space Station. Speculation focused on to the refurbished Soviet rocket engines Orbital was using, and in a conference call today, Orbital CEO David Thompson confirmed that the speculation was probably right.

"While still preliminary and subject to change, the current evidence strongly suggests that one of the two AJ26 main engines that powered Antares' first stage failed about 15 seconds after ignition," Thompson said, stressing that more analysis needs to be done. "At this time, we believe the failure likely originated in, or directly affected, the turbopump machinery of this engine."

Built in the '60s for the Soviet moon program

The engines were built in the 1960s for the Soviet moon program, then bought and refurbished by an American rocket company. Though the first three ISS resupply launches went smoothly, Orbital has had problems with the engine before, including a failed test last spring. Thompson says the company had been planning to upgrade its engines in 2017, but after last week’s explosion will likely retire the engine entirely and fast-track a replacement for 2016.

In the meantime, Orbital plans to honor the rest of its $1.9 billion NASA resupply contract by buying space on other rockets. Thompson says Orbital is in talks with three other companies, two American and one European, but didn’t give names.

SpaceX also holds a resupply contract for the ISS, worth $1.6 billion, and has so far completed four of 12 launches using its Dragon capsule and Falcon 9 rocket. Elon Musk, SpaceX’s founder and CEO, has mocked Orbital’s reliance on Soviet engines in the past, saying that "it sounds like the punchline to a joke."