Complex sentence: It will be used on the company's own rocket, Electron, in a similar arrangement to the Falcon 9, using nine identical engines on the first stage and one, optimized for vacuum with a longer nozzle, on the second stage.
Split into simpler sentences: It will be used on the company's own rocket, Electron. This is a similar arrangement to the Falcon 9, using nine identical engines on the first stage and one, optimized for vacuum with a longer nozzle, on the second stage.