Hot-firing tests were carried out on a 3-cell GH2/GO2 linear aerospike nozzle engine with round-to-rectangle primary nozzles.The primary nozzles and inner layer of the combustion chambers were made of ablation-resistant W-Cu alloy and the aerospike ramp was made of steel.Data measured in the tests and data analyses were presented.The aerospike nozzle performance and pressure at five locations along aerospike ramp were obtained under two NPR(nozzle pressure ratio)

which is the ratio of combustion chamber pressure to ambient pressure.It is shown that test aerospike nozzle has good altitude compensability of thrust.High nozzle thrust efficiencies were yielded in the tests.Near NPR value of 50

nozzle efficiency was 92% to 93.5% and nozzle efficiency is 95% to 96% near NPR value of 350.Numerically predicted results are in good agreements with test data.