The U.S. Air Force is drawing up a new hypersonic development road map which, to the delight of many and the fear of some, revives the concept of a reusable flight research vehicle similar to the abandoned Blackswift.
The surprise plan to reincarnate an ambitious, horizontal takeoff and landing hypersonic vehicle also repeats the equally-difficult challenge of powering it with a turbine-based combined cycle. The high-speed reusable flight research vehicle (HSRFRV), as it is dubbed, is not due to fly until October 2021 - which may be a good thing or a bad thing, depending on your perspective.
For many hypersonic veterans, living through the vicissitudes of the post-NASP era, the rise and fall of Darpa’s Blackswift was a reminder that technological ambition can quickly be eclipsed by funding expediency. Ten years is a long time to wait for the axe to fall again, particularly as the money and resources already spent may have been better allocated on other, more certain routes. This is essentially the argument of more cautious voices such as AIAA president and former Air Force Chief Scientist Mark Lewis who believes more emphasis should be placed on building-up experience using “weaponized” X-51s.
For others, however, the goal represents a clarion call for both the Air Force and U.S. industry. For the pragmatists celebrating the birth of a coherent hypersonic road map and a follow-on strategy to the X-51, the timeline of the HSRFRV seems within the boundary of ‘do-able.’ Certainly Steven Walker, Deputy Asst. Sec of the Air Force for Science, Technology & Engineering, and the former Blackswift program manager at Darpa, believes so.
Roadmap could include weaponized X-51-like variants. (AFRL)
While HSRFRV is further down the road, the nearer term destinations appear to be a well-thought out series of optional high-speed weapon concepts. The weapons path would be relatively fast-track, with development of a demonstrator over five years and first flight by October 2016. Three major options for the demonstrator include an “X-51-like” vehicle that would, like the WaveRider, be air-launched from a B-52. A second option would cover development of a “tactically-compliant” high-speed version that could be internally-carried by the Northrop Grumman B-2, and externally by the Lockheed Martin F-35. A third option, also involving a B-2/F-35 capable launch, would be an all-new vehicle configuration.
Read more about these developments: USAF Revives Blackswift Hypersonic-Like Plan