I assume this will expedite a decision on possibly using an ATK (Dark Knight based?) solid for S1?
Orbital already knows that it has to replace NK-33 with something after 2016 or thereabouts. That something could be RD-181 or solids or something else. This test failure doesn't change anything in that regard.
- Ed Kyle
Assuming the engine cannot be repaired, and Orbital/ATK would like continual service to ISS, it moves the deadline closer by a few months.
My understanding is that Aerojet had some excess NK-33 engines that could be assigned to this first contract if needed.
- Ed Kyle
After the investigation I'm more than willing to remove the scrap metal
So, did they have a root cause for this nailed down before the ORB-2 launch? I know that the AJ-26s on Antares 4 passed their testing, but wouldn't you like to rule out commonality? The ones used in Antares-4 (which did, indeed, perform without hiccup) might've passed testing, as well as the flight itself - despite being out of design parameters..?
So, did they have a root cause for this nailed down before the ORB-2 launch?
They wouldn't have launched unless they were convinced they nailed it down. They did borescope inspections of these engines to verify they weren't affected by whatever that was AFAIK.
