un to achieve a speed of Mach 7.1. The scramjet successfully provided a positive thrush to drag ratio for 25 milliseconds. This was a significant test because it was the first time scramjet technology was tested in actual flight as opposed to a wind tunnel test. It should be noted however, that the test engine did not use hydrogen, as the operational scramjets will most likely do. Instead ethylene was used because is enabled a larger quantity of fuel to be used on the test projectile. Using ethylene also eliminated the need to regulate fuel pressure. Early attempts failed because the projectile broke up under the 10,000g force exerted when the gun was fired. (Phillips, E. 2001) There have since been attempts at airborne scramjet aircraft. NASA’s X-43A is a scramjet powered test vehicle. The X-43 is a 12 feet long unpiloted aircraft. It is designed to be carried to an altitude of 20,000 feet by a B-52. At that point it is released and a rocket powers the X-43 to an altitude of 100,000 feet. The scramjet is ignited, data is recorded and the aircraft descends into the ocean. During the first testing of the X-43 problems arose with the Pegasus booster rocket and the ship had to be destroyed. All evidence points to the booster causing the problem, not the test vehicle. There are two X-43s remaining and hopefully further research will be conducted. (NASA prepares for…)Success of the scramjet could lead to affordable hypersonic travel. An aircraft capable of speeds up to Mach 25 could make the trip from New York to Tokyo in less than 2 hours. This would drastically change international travel. Scramjet power would also be a superior means of military transportation. The applications could range from large transport aircraft to scram powered missles. With the proper funding and research a scramjet powered vehicle could be reality in the near future. ...
