Could the XB-70 Valkyrie be feasible today?

[Rod]

http://www.aerospaceweb.org/aircraft/research/xb70/

 

Given all the advances in technology since the XB-70 was cancelled; adavances in materials, composites, electronics, engines, etc... could the XB-70 be built today with the same specifications of performance of the original concept?

 

I am sure it could be built, but the real question is could it be built at reasonable costs compares to the B-1B and B-2?

[Burncycle360]

Given all the advances in technology since the XB-70 was cancelled; adavances in materials, composites, electronics, engines, etc... could the XB-70 be built today with the same specifications of performance of the original concept?

 

To be honest, with our procurement system, I don't think we could build brand new relatively low tech B-52's if we wanted to. Much less XB-70's...

 

However hypersonic UAV's might make it obsolete anyway

[p620346]

Originally posted by Rod:

[i am sure it could be built, but the real question is could it be built at reasonable costs compares to the B-1B and B-2?[/i]

 

I would think that in comparison to the B-2, anything could be built at a "reasonable" cost.

[Ol Paint]

Probably. Titanium costs have come down, meaning that the airframe could use lighter structure (the original had a lot of steel). Likewise, sandwich panel construction techniques, composites, avionics, and many other areas have improved significantly over the original, reducing weight and volume requirements. Engines and fuels may still be problematic, but the F120 would seem to be a good baseline engine core from which to start development.

 

I am a advocate of "re-activating" the XB-70 program to develop similar aircraft since I think the aircraft is more relevant today than it was originally. (Note, I don't mean that Ship #1 should be pulled from the AF Museum. That one is redlined at Mach 2.54 and had hydraulic issues, so wouldn't be of much benefit to a new program.) In a world where we want to fly bombing missions from CONUS halfway around the world, doing this at 3-4x the speed would seem to make sense from a physiological standpoint. I am willing to bet that today's aircrews wouldn't mind flying a 2hr transit, 4hr on-station, 2hr home mission profile, rather than 8hr-4hr-8hr as with today's aircraft (assuming 4500mi transit distance).

 

As I recall, the XB-70 was supposed to fly 7,500mi at 3.0 Mach, which would mean only one tanking in theater. And payload was to be 50,000lb, although I don't know if this was the max bombload, or if it was supposed to carry 50,000lb to 7,500 miles.

 

I would settle for the B-1R, if you twisted my arm...

 

Douglas

[MiloMorai]

Just blabbering.

 

Is not the B-1 for low level and the B-2 for stealth? The XB-70 was for high altitudes, was it not? It would stand out on radar a light year away.

[yak_v]

I don't think that there is a point to it. Against a reasonable AD system armed with S-300s XB-70 would be toast, while against Iraq/Afganistan/Iran type of a threat it's a giant overkill and is not needed. Even B-52 would work against those targets.

 

If a very fast responce is needed develop a non-nuclear IRBM (kind of like Russian Tochka or Iskander) with a range of 1000 miles or so. They will get there facter than XB-70 could. For any other situation B-1B or cruise missiles are more than enough.

 

Vladimir

[DavT]

What about using it as an Airborne Laser System platform? I can arrive on station a lot faster than a Boeing, though I don't think the Valkyrie has the internal volume to hold the current ABL System.

[yak_v]

Originally posted by DavT:

What about using it as an Airborne Laser System platform? I can arrive on station a lot faster than a Boeing, though I don't think the Valkyrie has the internal volume to hold the current ABL System.

 

 

It probably doesn't have the endurance to stay on station for very long, plus, it would probably make it more difficult to target stuff with it, since Valkyrie's cruising speed is much fater than Boeing's. Besidies, it really doesn't matter how fast it can arrive on station, since it will either be there in the right moment or it will never get there on time, since even longest flying ICBMs will take only 30 min to reach their targets and unless the plane is near the target it will never get there in time, whether it's a Boeing or Valkyrie.

 

Vladimir

[Scott Cunningham]

B-70 was not feasible in 1960 (a one mission, one profile aircraft). The B-58 was retired early because it could only drop nuclear bombs on cities. Thats all the B-70 could do as well.

 

It is still a superb airframe, and technologically fascinating.

[Kenneth P. Katz]

The XB-70 was and would be astronomically expensive to build, operate and maintain, and it would be no more capable than a B-52H carrying modern munitions. If one were attacking a heavily defended target, I'd rather shoot a load of AGM-158 missiles than go with a B-70.

[Ivanhoe]

Its easy to visualize a supercruise heavy bomber as a standoff weapon platform, but the probable cost/benefit ratio is nowhere near low enough to consider an R&T budget, much less going into production. The current mix of SSNs, DDGs, Bones and Buffs for initial strike provides a lot more flexibility and overall utility.

 

Aside from solving all the known technical problems, there would be a pretty big task of designing and building the fab shops, and the American aerospace biz ain't healthy enough to engage in any more Pyrrhic victories.

 

Hypothetically a dual-use program could concurrently develop a supercruise heavy bomber and a supercruise airliner to spread the costs a bit, but we know the latter aircraft is an economic nonstarter, period.

 

I'd rather see an acceleration of both 6.1 and 6.2 work applicable to supercruise and highly survivable cruise missiles.

[Ol Paint]

Originally posted by Scott Cunningham:

B-70 was not feasible in 1960 (a one mission, one profile aircraft). The B-58 was retired early because it could only drop nuclear bombs on cities. Thats all the B-70 could do as well.

 

It is still a superb airframe, and technologically fascinating.

 

Actually, what killed the B-58 was the astronomically high maintenance costs brought about by the way the aircraft was built. It seems that the structural loads were carried by sandwich panels over most of the airframe. As a result, these panels couldn't be removed from the aircraft unless the entire airframe was placed in a massive jig where it had to remain until all the panels were reinstalled. This meant that the maintenance man-hours required to perform relatively simple maintenance tasks were astronomical.

 

The B-58 could carry conventional munitions in the TCP--Two Component Pod--and there was a program to develop a conventional munitions carriage capability on four underwing hardpoints.

 

I don't think that the endurance of the XB-70 would be a factor. The aircraft was designed to fly 7,500mi without being refueled at Mach 3, which works out to ~3hr 20min of flying time. At subsonic speeds, you can cut the afterburners out, halving the SFC of the engines and cutting power by ~50%. This would give a subsonic flight time on the order of 3-4x the supersonic endurance, or 10-13hr. If we postulate a mission to a target 4,000mi away, the aircraft will take two hours to get there (burning ~57% of its onboard fuel--assuming a 500mi reserve at Mach 3), loiter for up to 4-5.5hrs, tank once from a tanker in theater, loiter for another 4-5.5hrs and return home. Total flight time: 12-15hrs with 8-11hrs on station. Of the total flight time, the aircraft will spend 60-70% of this time over the target area (assuming ~1 hr to refuel from the tanker).

 

By comparison, using the 4,825mi mission radius with 10,000lb as listed on Joe Baugher's site, the B-52 @ 525mph will take 7.6hr to reach the target, loiter for 10.75hr before tanking, spend another 10.75hr over the target, then return home. This mission will take a total flight time of 36.7hr with ~21.5hrs over the target. 58.6% of the mission flight time will be spent in theater, which matches the bottom of the XB-70 potential.

 

Now, this comparison is taking the paper number for the XB-70 range as 7,500mi. According to Baugher, the XB-70A had a combat range of 3,419mi. To me, this looks like radius, but he may be correct for achieved performance. As an aside, the YJ93 has SFC of 0.7(dry)/1.8(wet) with thrust ratings of 22,000lb (military)/31,000lb (wet), which is pretty dang good for a turbojet.

 

Personally, I don't think an XB-70 type aircraft need be any more vulnerable to air defenses than the B-52. We still have the B-2 and B-1 for the penetration roles, the B-70 (or a similar aircraft) would take over the B-52 "bomb truck" role. What is more important in the types of conflicts we have been engaging in recently is the round-trip mission time. I have a tough time believing that the crews of B-52s and B-2s that are flying 30+hr round trip missions are no more fatigued at the end of the mission than a crew that has less than half of the mission flight time. It is for this reason that the B-1R program makes a lot of sense to me.

 

Douglas

[Balabanov]

The best possible rapid reaction delivery system will be an ICBM with GPS-guided (JDAM-style) MIRV's. I'm sure it is technologically feasible and the R&D will be just a fraction of the cost of a revitalised B-70 programme. The greatest problem, of course, is to convince Russia, China, etc. that you are not launching pre-emptively on them

 

All the best,

IBB

[Rod]

Originally posted by Balabanov:

The best possible rapid reaction delivery system will be an ICBM with GPS-guided (JDAM-style) MIRV's.  I'm sure it is technologically feasible and the R&D will be just a fraction of the cost of a revitalised B-70 programme.  The greatest problem, of course, is to convince Russia, China, etc. that you are not launching pre-emptively on them  

 

All the best,

IBB

 

Or perhaps a bomber version of a B-747, 777 or 7E7. Put a bunch of JDAMs inside, put some bomb bays and you got a bomb-truck.

[swerve]

Originally posted by Rod:

Or perhaps a bomber version of a B-747, 777 or 7E7. Put a bunch of JDAMs inside, put some bomb bays and you got a bomb-truck.

 

EADS have proposed an A340 bomber to the French Air Force carrying palletised Scalp/Storm Shadow.

[Balabanov]

Originally posted by Rod:

Or perhaps a bomber version of a B-747, 777 or 7E7. Put a bunch of JDAMs inside, put some bomb bays and you got a bomb-truck.

 

Sure thing, I only had in mind tha fastest response technologically available today -- the B-70 would be required only if you want to be able to hit distant targets fast. A JDAM-type MIRV's will be delivered much faster, and just as accurate. Now the price is another question How much does an ICBM-type carrier cost? For a nuclear strategic delivery system, no cost is too high. For a conventional weapons delivery, it may come pricey

 

Best,

IBB

[Smitty]

Originally posted by swerve:

EADS have proposed an A340 bomber to the French Air Force carrying palletised Scalp/Storm Shadow.

 

The USAF is looking at arming AC-130s with cruise missiles or bombs, and at a new concept called BMACK (Bomber (, SpecOps/intel (M), gunship (A), transport ©, tanker (K)), that would be a stealthy C-130-sized, reconfigurable, STOL aircraft that could carry up to 40 JDAMS in the bomber config.

http://www.aviationnow.com/avnow/news/chan...ws/11294wna.xml

[Ol Paint]

Originally posted by Balabanov:

Sure thing, I only had in mind tha fastest response technologically available today -- the B-70 would be required only if you want to be able to hit distant targets fast.  A JDAM-type MIRV's will be delivered much faster, and just as accurate.  Now the price is another question    How much does an ICBM-type carrier cost?  For a nuclear strategic delivery system, no cost is too high.  For a conventional weapons delivery, it may come pricey  

 

Best,

IBB

 

Not quite. As I stated below, the other reason to invest in a high speed aircraft would be to cut down on the mission duration to increase the effectiveness of your air crews and to accomplish the mission in the most efficient manner possible.

 

In the case of the B-52 vs. B-70, we have the same payload being delivered for 1/3 the flight hours. Whether this also equates to lower maintenance is questionable when comparing supersonic vs subsonic aircraft, but the potential is there to fly more missions with a fixed number of aircraft. In the same 36hr time period, the B-70 could fly two round trips with a 12hr maintenance/crew rest/rearming period with a total on-station time of 16hrs delivering 20,000lb of ordnance vs. 1 B-52 mission with 20.5hrs on-station, delivering 10,000lb, and no maintenance/rearming/crew rest (assuming that the B-52s no longer have the crew rest areas they did when new). The B-70 crew would have logged 24hrs of flight time, while the B-52 crew logged 36.

 

Consider an operation lasting 2 weeks. Which set of crews is going to be more effective at the end of that period? Over the course of 2 weeks, the B-52 could make 7 round trips with 12hr intervals between missions, equating to 143.5hrs on station and 70,000lb of ordnance delivered. The B-70 could make 14 sorties during this time (also with 12hr intervals between sorties) for a total on-station time of 224hrs and 140,000lb of ordnance delivered.

 

There are some gross generalizations and assumptions in this comparison. I assumed that both aircraft were carrying a 10,000lb payload and tanking once during the mission--in reality, both aircraft would probably exchange some fuel for payload and tank a couple of times. I assumed that the B-70 would achieve a range of 7,500mi with 10,000lb and that the B-52 would achieve 9,650mi with the same load. I assumed that neither the B-52 or the B-70 would require additional maintenance in the 2 week period outside of the 12hr turnaround times. For the rest of my assumptions, see my previous post.

 

Douglas

[swerve]

Originally posted by Smitty:

The USAF is looking at arming AC-130s with cruise missiles or bombs, and at a new concept called BMACK  (Bomber (, SpecOps/intel (M), gunship (A), transport ©, tanker (K)), that would be a stealthy C-130-sized, reconfigurable, STOL aircraft that could carry up to 40 JDAMS in the bomber config.

http://www.aviationnow.com/avnow/news/chan...ws/11294wna.xml

 

 

Interesting. The proposed EADS palletised delivery system would also fit into freighters such as the A400M (surprise!), with no structural mods. I think they'd need some extra electronics.

[Ol Paint]

The USAF is apparently interested in high-speed weapons delivery systems, although the thrust of the program seems to be unmanned delivery.

Nov 2003, DARPA and the USAF have just released contracts to start development for their FALCON program, which is an acronym for Force Application and Launch from CONtinental United States.

 

It is to be developed in two parts with the SLV expected to be complete by 2010 and a HCV expected by 2025. Nine contractors were selected to perform a phase one level systems definition for the SLV.

 

The goal of the joint DARPA/Air Force Program is to develop and validate in flight technologies that will enable both near term and far term capability to demonstrate affordable and responsive space lift capabilities.

 

The SLV will be designed to place small satellites into a Sun Synchronous Orbit with a payload ranging from 200 Lbs up to 1000 Lbs at a 450 mile orbit at a 79 degree inclination.

 

In addition, a total launch cost of less than 5 million dollars or less is desired. Existing launch systems are costly and in limited supply so the solicitation specifically requested innovative technologies to reduce launch cost and improve launch responsiveness.

 

Emphasis will be on incremental flight-testing using a building block approach.

 

USAF wants to build the means to attack any target on the globe within 12 hours of an order to do so. That requirement stems from an April 2003 Air Staff study titled 'Long-Range Global Precision Engagement.' In it, the Air Force, working with the Joint Staff and Office of the Secretary of Defense, put strike capabilities into three categories: prompt global strike, prompt theater strike, and persistent area strike.

 

USAF believes the products of Falcon will fulfill, to a great degree, the prompt global strike element. The ability to conduct prompt global strike would dissuade or deter enemies because they would know that the US could 'hold at risk or strike high-value targets anytime and anywhere on the globe,' said the study. Such a technology would also eliminate the need for intratheater buildup before conducting a strike.

 

.::: Phase I - System Definition ( 3rd Quarter 2003 - 2nd Quarter 2004) :::.

Task I - (SLV*)

FALCON Phase I, Task 1 (SLV) contractors will receive between $350,000 and $540,000 each for their Phase I effort.

Task 1 contractors are listed below.

 

Air Launch LLC, Reno Nevada

Andrews Space Inc., Seattle Washington

Exquadrum Inc., Victorville California

KT Engineering, Huntsville Alabama

Lockheed Martin Corp., New Orleans Louisiana

Microcosm Inc., El Segundo California

Orbital Sciences Corp., Dulles Virginia

Schafer Corp., Chelmsford Massachusetts

Space Exploration Technologies, El Segundo California

 

In FALCON Phase I Task 1 (SLV), contractors will develop conceptual designs, performance predictions, cost objectives, and development and demonstration plans for the SLV*. The SLV will provide a low-cost, responsive launch capability capable of placing a small satellite or other payload weighing approximately 1,000 pounds into a low Earth orbit at a total launch cost of less than $5,000,000 (excluding payload and payload integration costs).

 

Task II - (HWS*)

FALCON Phase I, Task 2 (HWS), contractors will receive between $1,200,000 and $1,500,000 each for their Phase I effort.

Task 2 contractors are listed below.

 

Andrews Space Inc., Seattle, Wash.

Lockheed Martin Corp., Lockheed Martin Aeronautics Co., Palmdale, Calif.

Northrop Grumman Corp., Air Combat Systems, El Segundo, Calif.

 

In FALCON Phase I Task 2 (HWS), contractors will develop conceptual designs, concepts of operations, and a demonstration plan and identify critical technologies for the Hypersonic Weapon Systems portion of the program, which includes the CAV*, the ECAV*, and the Hypersonic Cruise Vehicle.

 

The Common Aero Vehicle will be an unpowered, maneuverable, hypersonic glide vehicle capable of carrying approximately 1,000 pounds of munitions, with a range of approximately 3,000 nautical miles.

 

The Enhanced Common Aero Vehicle would be a more advanced design that offered substantially greater range and improved maneuverability.

 

The reusable Hypersonic Cruise Vehicle will be an autonomous aircraft capable of taking off from a conventional military runway and striking targets 9,000 nautical miles distant in less than two hours.

 

 

.::: Phase II - Design & Develop (2nd Quarter 2004 - 3rd Quarter 2007) :::. Back to the top

Task I - (SLV)

In FALCON Phase II, the Task 1, SLV, objective is to demonstrate and flight-test all significant characteristics of the operational launch vehicle.

 

One or more SLV agreements/contracts will be extended into Phase II as the result of a competitive down-select among Phase I participants.

 

Phase II will develop an SLV design in parallel with CAV development. Coordination and information exchange between SLV and HWS contractors will take place during Phase II to integrate the physical and functional characteristics of the SLV and Enhanced CAV.

 

Deliverables will include refinement of CONOPS* for each SLV approach, a detailed flight demonstration plan of each booster system, and flight-test of a single low-cost booster design.

 

Task II - (HWS)

In FALCON Phase II, the Task 2, HWS, objective is to flight-test a CAV and develop critical designs for Enhanced CAV and HCV* demonstration systems incorporating flight-ready hypersonic technologies.

 

Up to two HWS agreements/contracts will be extended to Phase II as the result of a competitive downselect among Phase I participants.

 

Phase II will execute an integrated plan to evolve both CAV and HCV designs and mature associated critical technologies.

This task will mature key enabling technologies applicable to both the Enhanced CAV and the reusable HCV design.

 

Extensive analytical and experimental effort will be conducted to bring a suite of these technologies to flight-readiness (TRL = 6). The HCV design will be evolved further and performance predictions made based on the revised design.

 

The CAV, Enhanced CAV, and HCV demonstrator preliminary and critical designs will be developed and risk mitigation plans enforced for all flight experiments planned.

 

Coordination and information exchange between SLV and HWS contractors will take place during Phase II to integrate the physical and functional characteristics of the SLV and Enhanced CAV in preparation for an integrated SLV/Enhanced CAV flight test in Phase III.

 

The government's decision to progress from Phase II to Phase III will, in part, be based on the delivered Phase II products which best address the below combination of information or events to meet the stated objectives:

 

Successful flight demonstration of an affordable, responsive booster SLV.

 

Successful 3,000 nautical mile, 800-second flight-test of the CAV demonstration system with a simulated unitary penetrator payload.

 

An Enhanced CAV critical design that will demonstrate a 9,000 nautical mile, 3000 second mission capability.

 

A HCV demonstrator critical design that incorporates at least three hypersonic technologies identified in Phase I; these three technologies will be developed to at least TRL = 6.

.::: Phase III - Weapon System Demonstrations (3rd Quarter 2007 - 2009) :::. Back to the top

Phase III will consist of a single task identified as Weapon System Demonstrations.

 

The objective is to flight-test an integrated SLV/Enhanced CAV system, and flight-test Enhanced CAV and HCV demonstrators to validate system and technology performance.

 

Phase III will be performed over a 30-month period during which the Enhanced CAV will be flown integrated with the SLV.

 

The CAV payload flown in the integrated CAV/SLV flight demonstration may be scaled relative to an operational CAV commensurate with the capabilities of the SLV flight demonstration system.

 

The balance of the Phase III effort will focus on demonstration of reusable technologies that are considered key to enabling future development of a hypersonic cruise vehicle.

 

Many of these same reusable technologies are expected to benefit Enhanced CAV designs as well. Key technologies will be integrated into an HCV demonstrator and flight-tested using a similar test approach taken in demonstrating the CAV.

Powered as well as unpowered versions of the HCV demonstrator may be tested to permit technology validation for longer duration flights and assessment of the implications of integrating propulsion systems with the vehicle design.

 

Douglas

[James1978]

Originally posted by swerve:

Interesting. The proposed EADS palletised delivery system would also fit into freighters such as the A400M (surprise!), with no structural mods. I think they'd need some extra electronics.

 

I don't suppose anyone has a link to more info on this palletised system?

[Burncycle360]

I think a fast bomber does have potential -- a UAV version of the Hypersoar

 

Kind of like an intercontinental cruise missile, but instead of the disposable kind it can be resused. Goes mach 10 skipping off the atmosphere, delivering payloads to strike multiple targets before returning home.

 

 

Or perhaps a bomber version of a B-747, 777 or 7E7. Put a bunch of JDAMs inside, put some bomb bays and you got a bomb-truck.

 

If we're talking airliners, BWB is supposed to come out about the same time B-52's retire... *shameless BWB plug*

 

It has the potential to carry a great deal more ordinance than a B-52, 747, or any other proposed airliner thusfar. (greater lifting capability, greater internal volume) with the same range and speed. It's total span and length is not much larger than the 747 too.

 

Keep in mind I mean a purpose built bomber based on the BWB, not a converted airliner- it's designed and built from the ground up as a bomber, but since the aircraft manufacturer can use many of the same manufacturing processes, tooling, and off the shelf parts I would imagine it would reduce development time and cost substationally.

 

Also it would be well suited for other long endurance/heavy payload missions (airborne laser, AWACS, C3I bird, JSTARS, airborne control center, tanker, etc).

 

Since the company will make parts anyway for the airline versions, parts should be plentiful and maintinence relatively cheap.

 

It's not stealthy, but I think it's important to still have a bomb truck. We'll be handicapped with our stealthy/fast silver bullets that are so few in number.

 

 

[Edited by Burncycle360 (30 Nov 2004).]

[swerve]

Originally posted by James1978:

I don't suppose anyone has a link to more info on this palletised system?

 

Since EADS haven't put it on their website, no. EADS aren't as bad as MBDA, who have "under construction" pages for products that have been in service for years, but I've never seen them put anything on their site until there's some hardware, & AFAIK it's just a paper - or rather CAD - proposal.

[gewing]

Can we modernize/resurrect the Pyewackett missile system at the same time?

 

Originally posted by Ol Paint:

Probably.  Titanium costs have come down, meaning that the airframe could use lighter structure (the original had a lot of steel).  Likewise, sandwich panel construction techniques, composites, avionics, and many other areas have improved significantly over the original, reducing weight and volume requirements.  Engines and fuels may still be problematic, but the F120 would seem to be a good baseline engine core from which to start development.

 

I am a advocate of "re-activating" the XB-70 program to develop similar aircraft since I think the aircraft is more relevant today than it was originally.  (Note, I don't mean that Ship #1 should be pulled from the AF Museum.  That one is redlined at Mach 2.54 and had hydraulic issues, so wouldn't be of much benefit to a new program.)  In a world where we want to fly bombing missions from CONUS halfway around the world, doing this at 3-4x the speed would seem to make sense from a physiological standpoint.  I am willing to bet that today's aircrews wouldn't mind flying a 2hr transit, 4hr on-station, 2hr home mission profile, rather than 8hr-4hr-8hr as with today's aircraft (assuming 4500mi transit distance).  

 

As I recall, the XB-70 was supposed to fly 7,500mi at 3.0 Mach, which would mean only one tanking in theater.  And payload was to be 50,000lb, although I don't know if this was the max bombload, or if it was supposed to carry 50,000lb to 7,500 miles.

 

I would settle for the B-1R, if you twisted my arm...    

 

Douglas

[gewing]

I was thinking use a modernized version as the first stage of a responsive small space launch system.

 

OTOH, could the mach 3+ start give enough boost for long range missile strikes? Imagine a system that starts off gliding at that speed. :0 ok, probably not possible, but...

 

Originally posted by Ivanhoe:

Its easy to visualize a supercruise heavy bomber as a standoff weapon platform, but the probable cost/benefit ratio is nowhere near low enough to consider an R&T budget, much less going into production. The current mix of SSNs, DDGs, Bones and Buffs for initial strike provides a lot more flexibility and overall utility.

 

Aside from solving all the known technical problems, there would be a pretty big task of designing and building the fab shops, and the American aerospace biz ain't healthy enough to engage in any more Pyrrhic victories.

 

Hypothetically a dual-use program could concurrently develop a supercruise heavy bomber and a supercruise airliner to spread the costs a bit, but we know the latter aircraft is an economic nonstarter, period.

 

I'd rather see an acceleration of both 6.1 and 6.2 work applicable to supercruise and highly survivable cruise missiles.