Aircraft Travels Faster Than Six Times the Speed of Sound

US Air Force, EDWARDS AIR FORCE BASE: Tests are under way at the Benefield Anechoic Facility here on the X-51 Scramjet-Waverider's antennas to ensure all of the X-51's antennas and communication systems are working properly. 
 
The X-51 is an autonomous vehicle with a scramjet engine enabling the aircraft to travel at a hypersonic speed — faster than six times the speed of sound. 
 
The testers are looking at two different types of antennas — a flight termination system antenna and telemetry antenna — that streamline all data from the X-51, including performance, air and engine data. 
 
The 412th Test Wing Hypersonic Flight Test Team, Electronic Warfare Directorate and Boeing began month-long testing Jan. 28. 
 
“We have to make sure we have good receiving and transmitting antennas before we actually fly the aircraft,” said 1st Lt. Richard Paek, the X-51 lead project engineer. “We also have to make sure we have good coverage of antenna patterns, spectrum of frequencies and bandwidth.” 
 
The Boeing test team mounted the antennas on an X-51 mock-up. An antenna in the Benefield Anechoic Facility will send signals to the mock-up, while an engineer determines if the aircraft is receiving the signal. 
 
“We are testing at the Benefield Anechoic Facility because it is unique,” said Maj. Raimone Roberts, the 412th TW Hypersonic Flight Test Team projects director. “We are able to isolate everything that is going on around so we can really ensure the antennas are picking up the right signals.” 
 
Ground stations at Ridley Mission Control Center here and at Naval Air Station Point Mugu at Ventura County, Calif., “will communicate with the X-51 during its flight (scheduled for August 2009),” Lieutenant Paek said. “Each ground station has requirements such as the strength of the radio frequency and bandwidth.” 
 
The aircraft will be loaded onto a B-52 Stratofortress. Boosted by an Army Tactical Cruise Missile, the X-51 will then be dropped from an altitude of 50,000 feet and will soar at hypersonic speed. 
 
“Hypersonics is the way of the future,” Major Roberts said. “This is a step in better understanding how hypersonic is going to perform and what benefits it will bring us as a military function.”