US AFRL HTHL studies ca.1994

[flateric]

Having seen numerous times this stuff, just recently could identify it as USAF Air Force Research Lab HTHL (horizontal take-off/horizontal landing) studies from the mid-90s.
Interesting that various first stage configurations are seen, in one case being used alone as a hypersonic strike platform, but second stage looks the same in all cases...strikingly resembling something from 2001:Space Odyssey...

 

[CFE]

Technically there wasn't an AFRL until 1997. But the study pics are certainly interesting. The first stage in the bottom pic reminds me of the postulated "Brilliant Buzzard" or Blackstar first stage.

I recall seeing a paper study, published online, depicting a similar vehicle from an Air Force study. The name of the program and title of the paper escape me

 

[airrocket]

The shape appears to be a waverider design. Quite popular around that time period seems we see less of the waverider concepts recently.

 

[flateric]

we see less of the waverider concepts recently.

HTV-3X Blackswift anf FALCON HCV OS are true waveriders, though...

 

[flateric]

Other paper sets another timeframe, and not surprisingly, these concepts are called a part of AFRL HyTECH implementation studies started in 1995.

The Air Force's Hypersonic Technology Program (HyTech) is presently developing a technology base for Mach 4-8 liquid-hydrocarbon fueled scramjet propulsion systems. The HyTech Program is a 9 year. $132M exploratory development program that was initiated in August 1995 at the direction of the Secretary of the Air Force after the termination of the National Aerospace Plane Program. The HyTech Program is managed within the Propulsion Directorate of the Air Force Research Laboratory. The goal of the HyTech Program is to develop and demonstrate the operability. performance and durability of a Mach 4-8 hydrocarbon scramjet propulsion system. This technology will provide a key stepping stone to developing a family of hypersonic military vehicles including air-to-surface missiles (first two pics in this post), global reconnaissance and/or strike aircraft (second pic in the fist post). and the first stage of a two-stage-to-orbit access to space vehicle (first post, first and third pics).

As a result of Department of Defense interest in the potential of hypersonic propulsion to enable new
capabilities for weapons, aircraft and space access, the US Air Force has supported a continuing investment in
hypersonic propulsion technology. Most recently that activity has been accomplished under the Hypersonic
Technology (HyTech) Program within the Air Force Research Laboratory Propulsion Directorate. This
program, started in 1995, has been directed at development of endothermically fueled (hydrocarbon) Mach 8
scramjet technology, including fuels, materials, structures, and subsystems.

ftp://ftp.rta.nato.int/PubFullText/RTO/EN/RTO-EN-AVT-116/EN-AVT-116-02-APP-06.pdf

 

[XP67_Moonbat]

These are in the hypersonic brief I just posted in Aerospace, in the first post. It's the 2007 hypersonics brief.

I also vaguely remember seeing them in AWST back around ca. 1998 maybe. I dunno, memory's a bit hazy as I was busy on the Truman playing Navy at the time.

http://www.secretprojects.co.uk/forum/index.php/topic,9502.0.html

 

[blackstar]

There were some proposals along these lines a little earlier than 1995. I talked to someone who worked on some studies of hypersonic long range AAMs. I believe she mentioned that she had worked on two studies, one of them was classified, the other not, but they were apparently similar. If I remember correctly, one was a potential replacement for the Navy's Phoenix missile. It would launch from a fighter such as an F-14, get boosted ballistically with a solid motor, then turn on the scramjet, head far downrange, and dive on its target. I used to have some of her briefing slides.

You can imagine all kinds of problems with this beyond the challenges of getting the scramjet to work. A couple of tough ones: 1-if the range is very long, how do you detect the target in the first place? 2-what do you do about terminal guidance, where the closing speed in an atmosphere is very high?

 

[quellish]

SOMEWHERE I have photos of TSTO concepts from the same period in the Arnold wind tunnels. These were all belly launched rather than dorsal though.

 

[flateric]

http://www.secretprojects.co.uk/forum/index.php/topic,5217.0/