Flight Test Instrumentation Solutions to Hypersonic Vehicles
In recent years there has been a significant increase in hypersonic vehicle design for passenger aircraft and hypersonic weapons like cruise missiles or glide vehicles. Many spaceplanes, including the space shuttle orbiter, have used hypersonics for years. Several experimental aircraft have also exceeded Mach 5. The record for the fastest crewed-powered aircraft is held by the X-15, which reached Mach 6.70 in 1967. Figure 1 shows a selection of aircraft that could sustain powered flight in Earth's atmosphere (excluding spacecraft) and their speeds.
Figure 1. Some notable aircraft and their max recorded/projected speeds
Around 40 hypersonic craft (aircraft or weapons) are being developed or proposed. These are primarily spaceplanes, experimental crafts, or technology testbeds. However, some of them are intended to carry passengers. Hypersonic weapons are one of the most active uses of this technology. Recent developments have led to significant investment in many countries, especially the United States, in order to increase both their offensive and defensive capabilities. Hypersonic missiles can be used for military purposes. They are capable of hitting a target 1,000 miles away in 12 minutes.
Although the benefits of hypersonic craft are clear (e.g., being able to travel from London to New York in one hour), it is not very easy to make this a reality. Because of their high speed, hypersonic vehicles are subject to highly challenging environmental conditions. This whitepaper discusses these issues and suggests how flight test instrumentation can help overcome them.