The pulse detonation engine (PDE) has recently become recognized as a possible new aerospace propulsion system. The PDE system has high thermal efficiency because of its constant-volume combustion and its simple tube structure. We are now constructing a simple PDE system, an ethylene-oxygen single-tube pulse detonation rocket (PDR), in order to verify that the PDR produces sufficient thrust performance for its application to rocketry even though it uses an intermittent fuel supply system and has a very simple structure. The PDR-FM is operated for three cycles at 10-12.5 Hz in frequency. Liquid ethylene (312K, 250g), oxygen gas (10MPa, 240g), and helium gas (15MPa, 8g) are the fuel, oxidizer, and purge gas, respectively. We measure thrust using a load cell coupled with a spring-damper system and directly measure momentum using a high speed video camera. From these experimental results, we found that effective specific impulses were almost identical to the partial filling model proposed by Endo et al. The maximum thrust and effective specific impulse reached 233.9 sec and 345.1 N, respectively, in the present experiment.