A key component of NASA’s X-59 Quiet SuperSonic Technology(QueSST) aircraft is undergoing vibration tests at the space agency’s Langley Research Center in Hampton, Virginia. The eXternal Vision System (XVS) is a special camera system that the pilot of the X-plane will use to see forward while the experimental supersonic craft is in flight.
When the X-59 takes to the skies in 2021, the pilot will be faced with a problem not often encountered since the Concorde fleet of supersonic passenger jetliners was retired. The X-59 is meant to test new technologies to build a new generation of supersonic commercial aircraft and, while it promises to overcome some of the drawbacks of Concorde, it will still share some of its difficulties.
One is that the ideal design of a long-range supersonic liner is essentially that of a needle-nosed dart. The annoying thing is that, though this shape may be fine from an aerodynamic point of view, it makes it extremely difficult for the pilot to see forward without a lot of complex mechanics, like Concorde’s droop nose and special sliding windscreen.
Being built by Lockheed Martin, the X-59 is taking a different approach with the XVS. This visual system uses a forward-facing camera and display system with image processing software that not only gives the pilot a virtual window on the airspace ahead, but also graphical flight data.
NASA says the XVS has already made in-flight tests and its pallet – which includes the processors, network equipment, video distribution, and power distribution components – camera and monitor are now going through ground vibration tests to ensure that it meets the structural safety requirements.
“We’re conducting proto-qualification, which in this case refers to the testing of equipment at vibration levels lower than qualification testing, but to the expected vibration levels of the flight environment to ensure the equipment will function nominally when installed on the X-59,” says Kemper Kibler, lead hardware engineer for the XVS. “This allows for the tested equipment to be flown as opposed to qualification testing which can test equipment to destruction.”Without this kind of test, a component could fail in such a way that causes damage to the aircraft or injures the flight crew. We want to identify and correct those issues in a controlled lab environment.”
The XVS is expected to go on to New York for temperature and altitude tests under simulated conditions similar to those expected to be encountered by the X-59 in flight.
When completed, the X-59 will be able to cruise at an altitude of 55,000 ft (17,000 m) at a speed of Mach 1.27 (940 mph, 1,512 km/h), yet produce a sonic boom of only 75 Perceived Level decibel (PLdB) – about as loud as a car door closing. Its purpose is to demonstrate new technologies that will minimize the infamous sonic boom, gather technical data and gauge public reactions to the aircraft, which will be used to rewrite American environmental regulations that were first drafted in the 1970s and were often prejudicial to overland commercial supersonic flight.