Spaceflight

The company released Aug. 26 details about the July 19 incident that led to the loss of the vehicle during one of the final tests before the vehicle’s second launch at Pacific Space Complex – Alaska on Kodiak Island.

In a statement, ABL Space Systems said it ignited the E2 engines in the first stage of the RS1 rocket in the test, but aborted the test after just half a second because of a low pressure reading in one engine that the company said was caused by a faulty pressure sensor.

The engines shut down, but a fire then broke out under the base of the vehicle, fed by fuel leaks from two engines. That fire was contained but could not be extinguished by either water or inert gas systems, and the company started offloading kerosene and liquid oxygen propellants from the vehicle.

An investigation of the two engines that had the fuel leaks that fed the fire showed “significant erosion” of their propellant injectors and liners that the company said is a sign of failure linked to combustion instability. “Our current leading theory is that differences in the Block 2 Stage 1 propellant feed system led to a higher energy startup than on the test stand, triggering an instability in 2 of 11 engines,” it stated.

The company did not offer a timeline for completing that work or for attempting another launch. ABL said it is returning the ground support equipment to Long Beach, California, for repairs while the next RS1 rocket is “well into production.”