Diode Laser Ignition of a Poly(Methyl Methacrylate) and Gaseous Oxygen Hybrid Motor

The performance of a diode laser igniter as a restart-capable device has been assessed for single-port, poly(methyl methacrylate) (PMMA)/gaseous oxygen (GOX) hybrid motors. For this testing a prototype version of the igniter has been designed and implemented as a substitute to a traditional methane/GOX torch ignition system. Ignition tests have been conducted at atmospheric ambient conditions using an experimental single-port motor setup. Using three PMMA fuel grains, a total of 46 successful motor ignitions and restarts were achieved. These tests were conducted using a single multimode diode laser with an output power of 10.84 W and a nominal pulse length of 1 s. In addition, a total of 24 successful ignitions and restarts were demonstrated in a vacuum chamber with the same prototype igniter on a flight-scale PMMA/GOX motor under development for smallsat applications. The ignition transient is compared against baseline results from a torch ignition system for atmospheric tests, and the ignition delay performance is considered across all tests.