Orbital ATK and engine-maker GenCorp disagree over cause of Antares crash

Under threat of significant financial losses, conflicting reports of what caused the October 28 (2014) Antares rocket crash have emerged – one from its manufacturer, Orbital ATK, and the other from its engine’s maker, Aerojet Rocketdyne.

Reuters reports,

Ronald Grabe, Orbital’s executive vice president and president of its flight systems group, told the annual Space Symposium conference that an investigation led by his company had concluded the explosion was caused by excessive wear in the bearings of the GenCorp engine.

In reply, GenCorp – which owns Aerojet – spokesperson Glenn Mahone says,

GenCorp’s investigation had also identified excessive wear of the bearings as the direct cause of the explosion that destroyed the rocket, but further research revealed that the bearings likely wore out due to “foreign object debris” in the engine.

According to Mahone, GenCrop’s investigation will be completed in three weeks but “the bulk of the work had been done”. The engine in question is actually a pair of AJ26-62 first-stage liquid-fuel engines – and it’s not clear yet if both engines were found to be damaged. Their designs are derived from the Soviet-era NK-33 engines, last used in the 1970s.

The AJ26-62 engine. Credit: Aerojet Rocketdyne
The AJ26-62 engine. Credit: Aerojet Rocketdyne

The kerosene they use can be seen burning up in a distinctly visible first explosion, which occurred moments after Antares lifted off from the launchpad in October last year. When it fell back down 15 seconds later, the second explosion incinerated over 2,200 kg of cargo Orbital ATK was ferrying to the ISS under a service contract with NASA.

Since it wasn’t a NASA mission per se, the space agency is not leading the investigation but only conducting one of its own. With a disagreement erupting over Orbital ATK and GenCorp, NASA could be the arbiter. However, also according to Reuters, it has no plans of making its report public.

Read: Orbital, GenCorp spar over cause of October rocket crash, Reuters