Extreme speed is once again becoming a prized quality at the Pentagon after a two decade long hiatus following the retirement of the
. Now Lockheed says it can build 3,800 MPH proof-of-concept jet in just a couple of years time, an aircraft that could lead to an fully operational “SR-72.”
Amazing as that sounds, does the Air Force even need such an aircraft at all?
Lockheed says it sees these so-called hypersonic weapons, a term that refers to speeds above Mach 5, as a very lucrative business space to invest in when it comes to supplying the U.S. with future air combat capabilities. During Lockheed’s annual media day,
:
“Lockheed Martin has a legacy of making fast aircraft. We are now producing a controllable, low-drag, aerodynamic configuration capable of stable operations from takeoff to subsonic, transonic, supersonic and hypersonic, to Mach 6.”
This is a strong statement. She admits not only that the company is producing technologies such as thermal protection, avionics and aerodynamic shapes for a hypersonic aircraft, but seemingly also that they’re working on an actual aircraft design that would combine these technologies into a functioning hypersonic airplane.
A Very Fast Mountain To Climb
The big stumbling block for hypersonic flight is that it is very hard to optimize an aircraft to fly at such extremely high-speeds and be able to takeoff and land from conventional runways. Parasite-type configurations, where the hypersonic vehicle is lifted to altitude by a larger mothership and then launched on its mission, are one answer, but these concepts have big design limitations and they’re extremely complex and expensive.
Lockheed’s
stepped out a few years ago, seemingly out of nowhere, and showed off its SR-72 concept for a hypersonic plane that could theoretically operate from runways without the need of a launch aircraft or booster of any type.
It would achieve such a capability through a “combined cycle” engine concept. This engine system would presumably get around the traditional limitations of individual turbojets, ramjets and scramjets which can only really work over their own specific velocity ranges. Obviously, installing three types of engines in an aircraft that is supposed to be super high-performance is not an option.
Lockheed’s hybrid combined cycle propulsion concept aims at solving this issue by using a turbine engine at low-speeds and a scramjet at high-speeds, with both sharing a common inlet and nozzle design while keeping their airflow paths separated.
Lockheed now wants to test their combined cycle engine, and all the other crazy technologies they have developed to operate a real aircraft at sustained hypersonic speeds, in the form of a flying technology demonstrator. On that, Hewson said:
“Most importantly, we’re proving a hypersonic aircraft can be produced at an affordable price. We estimate it will cost less than $1 billion to develop, build and fly a demonstrator aircraft the size of an F-22.”
Lockheed
, so we are not talking about a long-term development program here. In fact, the the stated timeline is so ambitious that it wouldn’t be surprising if the project was already underway in classified form.
Reconnaissance Has Changed
Even if Lockheed can build such an aircraft, does the Pentagon actually need such a weapon system? An SR-72-like aircraft would be unmanned and would have both a reconnaissance and rapid global strike role, but there are at least partial and possibly much cheaper alternatives to building a high-flying “silver-bullet” extreme performance jet.
The thing is, a super-high speed aircraft to replace the SR-71 has been sort of the aerospace-defense world’s white whale. Some very high-profile and respected journalists were seemingly obsessed with the potential existence of such a craft throughout the 1980s and 1990s, greatly enhancing the mythology of a possible “Aurora” spy jet.
It seems that so many have desperately wanted there to be a replacement for the SR-71 Blackbird, something even higher flying and faster than its predecessor, regardless of if there was ever even a real demand for one. In the end there has been no concrete evidence to support the existence of such a machine, and especially not a fleet of them in an operational form.
There are plenty of good reasons that a Blackbird successor never happened. The fact that satellites could provide the SR-71's “moment in time”
was big factor. Air defenses have also come a long way as computer and sensor technology has advanced.
Yet maybe the biggest reason was that persistent, penetrating reconnaissance has been all the rage over the last few decades—not ultra-fast spy planes.
The SR-71 was limited to taking a snapshot in time, very similar to that of reconnaissance satellite. Its main advantage is that it could show up unannounced and be gone very quickly while satellites are much more predictable due to the confines of their orbits. Aided by stealth technology, slow but largely invisible to radar persistent reconnaissance aircraft could survey the enemy over long periods of time, without them ever knowing they were being watched. Even more important, they could do so deep in enemy airspace, not along their borders.
Think of it as the difference between taking a photo of an birthday party in a park from 200 feet away with a long camera lens, and shooting hours of video of that same event while mingling among the crowd. Obviously the latter tells a much more complete story of the party. The video camera also allows the shooter to record audio of the event. Similarly, with persistent reconnaissance capable of penetrating enemy airspace you can bank all types of radio emissions and even atmospheric samples over time.
If a picture is worth a thousand words, then a video is worth a million.
This reconnaissance revolution really began with Northrop’s
, otherwise known as Tacit Blue. or more lovingly, the Whale. Its stealth design, hard to detect sensors, and data link technologies proved that a surveillance asset could survive and spy for long periods of time even while operating deep over enemy territory.
Eventually, this concept would evolve into the stunted RQ-3 Darkstar. Yet that program eventually would give birth
The RQ-170 has kept tabs on Iran’s nuclear program and helped hunt down Osama Bin Laden. It has also likely spied on other nuclear programs, such as North Korea’s, and friendlier ones too, such as Pakistan’s.
Although the bat-wing and stealthy RQ-170 looks cool, it is a downright humble machine compared to something like hypersonic spy plane. It is slow, small, doesn’t break altitude records and likely doesn’t even represent anything near the top end of American aerospace and weapons systems ingenuity. But it does what the Blackbird or its potential successor cannot, be the most obsessive of voyeurs, lurking and watching for hours on end in places it shouldn’t be.
The RQ-170 is just one program that has advanced the penetrating persistence reconnaissance concept, there are certainly others, and they are probably much more advanced than the RQ-170 ever will be.
The shadowy high-altitude, long-endurance penetrator
, a Northrop product that has been all but admitted to existing by the USAF, likely takes the persistent penetrating surveillance aircraft concept to a much higher level, both figuratively and literally.
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