It will not be much higher than current rocket engines. The theoretical upper limit, for the exhaust velocity of a hydrogen-oxygen engine is about 5270m/s. The

It will not be much higher than current rocket engines. The theoretical upper limit, for the exhaust velocity of a hydrogen-oxygen engine is about 5270m/s. The best actually constructed rocket engines have c=4600m/s in vacuum. So the thermal efficiency of rocket engines can already be upwards of 75%. So there's not that much room to improve. Since the authors seem to be careful not to mention the actual exhaust velocity, I'm guessing that it is actually lower than that of rocket engine. It can potentially be higher, but there is probably still a ways to go. Another factor is thrust to weight ratio. For modern rocket engines it is close to 100. For this detonation prototype it's probably very low. So no, don't expect detonation engines on rockets any time soon.