eAc (Environmental Aeroscience Corp) developed and fired the first solid propellant Aerospike motor in 2003. Aerospike nozzles are designed to be altitude compensating and self adjust the expansion ratio making them extremely useful for ground-launched sounding rockets. This feature is specifically useful for long burn hybrid rocket applications. Several design verification tests firings using short burn solid propellants, with the goal of applying the technology to the long burn Hybrid motors.