March 11, 2013

Is the "black" RATTLRS missile an F-35 sales sweetener?

Artist's mockup of an F-35 firing a jet powered supersonic missile Revolutionary Approach To Time Critical Long Range Strike (RATTLRS)
It may well be that an operational missile derivative (now a "black" the US term for secret project) of the RATTLRS concept has been rolled into the sale of F-35 as a sweetener to encourage buyers for the problematic-underdeveloped F-35. Such a missile may be the secret weapon the F-35 sales team and USAF officers have been hinting at in the Australian press. 
The reference in the Australian press was in an Australia's ABC TV Four Corners "Reach for the sky" on February 18, 2013 :

"[civilian presenter] ANDREW FOWLER: And it's even got a weapon that's a closely guarded secret.

LT. GENERAL CHRIS BOGDAN, EXECUTIVE OFFICER, F-35 JOINT PROGRAM OFFICE: Those are the crown jewels of the program and that's what makes the F-35 special.

ANDREW FOWLER: So asserting that to the public, it's really saying 'trust us'?"

RATTLRS Derivative More Likely Lockheed Martin's Secret Weapon

The US-UK Revolutionary Approach To Time Critical Long Range Strike (RATTLRS) appears to have gone "black" as it likely enters its practical-operational phase.

After some reconsideration - my February 28, 2013 post F-35 being sold with promise of a hypersonic missile? may be incorrect - as a hypersonic (Mach 5+) missile seems to involve too may technical problems to be used as a weapon in the next two decades. Hypersonic speed in the atmosphere:

- generates tremendous heat which within minutes melts available missile skin materials;
- heat adversely effects electronics;
-  and the large heat signature is unstealthy (showing up on infrared and other sensors while drawing in heat seeking SAMs or air to air missiles).

There are also range problems. The force needed to penetrate (or push aside) atmosphere at hypersonic velocity severely limits range. Two or more powerplants used to make hypersonic velocity possible involve prohibitive weigh increases which also limit range. The only way around these problems seems to be a weapon in the vacuum or "ether" of space - a role already performed by multistage ballistic missiles.

All this suggests high supersonic flight (up to Mach 4) is more appropriate for longer range, some stealth, while generating less material damaging heat. Also RATTLRS testing indicates turbo jets are capable of Mach speeds just below hypersonic.

Meanwhile it is unlikely that other missile developments mentioned in  F-35 being sold with promise of a hypersonic missile? are the "silver bullet" boosting F-35 sales. The West is unlikely to have built a missile similar to the BrahMos due to its rocket and ramjet's range limitations (officially around 300 kilometres). It is unknown to what extent the JASSM may have adopted RATTLRS technology (such as the jet engine) or whether JASSM may have in fact merged with RATTLRS.

In recognition of hypersonic heat and range problems the RATTLRS project has adopted an evolutionary approach - high supersonic speed (between Mach 3 and 4) using a single turbo-jet engine for simplicity and weight saving.


Popular Mechanics says about the RATTLRS YJ102R turbine engine "might be the most powerful turbojet on the planet—at least by weight. It’s barely bigger than two breadboxes."


Rolls-Royce announced on January 12, 2009 that it had successfully completed an initial test of its advanced, high-specific thrust YJ102R engine at the Indianapolis, Indiana facility. This test is the first of a series to be performed by LibertyWorks (Rolls-Royce North American Technologies Inc) , the company's research unit, and is designed to validate critical performance criteria under its High Speed Turbine Engine Demonstration (HiSTED) contract with the US Air Force Research Laboratory (AFRL).
Janes provides details of the requirement and thinking behind super-hyper sonic missile systems.
"The US has been examining a range of very high-speed strike weapon concepts for a number of years. These weapons, both sea- and air-launched, have been drawn up for use against mobile and/or time-critical targets, along with hardened and buried targets. In all cases the weapons rely on the kinetic effects of a ramjet powerplant to attain the velocities needed to be effective against such target sets...The optimum penetration effect of a weapon in this class would be between 30 and 55 metres." discusses performance requirements for RATTLRS including the jet turbine alone:

- boosting speed to Mach 3 to 4
- a range of up to 1,000 km
- can be air-launched by the F/A-18 E/F (Super Hornet), F-22 and F-35 (JSF)
- maximum missile weight of 1,800 lbs with a 500 lbs payload/warhead


Project Going "Black"

Increasing the likelihood that the F-35 builder Lockheed Martin has combined the sale with an operational RATTLRS missile development is: :

 "On 01 February 2005 the Office of Naval Research awarded Lockheed Martin a phase two contract N00014-04-D-0068-0003 for $157,443,201 including options...Lockheed Martin is teamed with Allison Advanced Development Company [acquired by Rolls-Royce] to develop technologies that will provide an advanced Mach 4+ integrated propulsion system in an operationally traceable airframe. The YJ102R developmental engine...As of May 2009 plans called for completing the RATTLRS flight test program by the end of 2009. [as of early 2010 this flight seems not to have happened]"


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