TACTOM synthetic guidance- now with video!

We mentioned the use of offboard guidance to guide a TACTOM Tomahawk missile against a moving naval target. Here’s the video.

[youtube https://www.youtube.com/watch?v=Jgv5ixxgTsQ]

That’s not a warhead, by the way. That’s simply leftover jet fuel from the Tomahawk’s engine burning. For test shots like this, the warhead is replaced with ballast and telemetry. First, you want to gather as much information as possible. Second, you want to do as little damage to the (relatively expensive) target as possible.  A warshot would have a 1000 pound blast/fragmentation warhead. While that likely wouldn’t sink the target, hitting so far above the waterline, it would certainly do a good deal of damage to any warship, likely rendering it a “mission kill” where it could not be expected to continue to operate in a threat environment.

And yes, pigeons is misspelled.

LRASM Program Notes

We’ve discussed US Navy offensive Anti-Surface Warfare a bit here lately. One program the Navy is pursuing to rebuilt its offensive capability is the Long Range Anti-Ship Missile, or LRASM. It hopes to equip both aircraft and ships with LRASM in the next few years, starting with aircraft first, and a shipboard model later.

The LRASM is essentially the Lockheed Joint Air to Surface Standoff Missile (AGM-158 JASSM) with an anti-ship seeker in place of the land attack guidance system. Interestingly, the first platform expected to actually field the LRASM is the Air Force’s B-1B. Given the efforts the Navy and Air Force have made toward integrating their warfighting capability in the far Pacific, this makes some sense. It makes even more sense in that the B-1B is the prime carrier for the JASSM, so integrating it and training crews is a lower hurdle. After the B-1B, the Navy expects to integrate LRASM on the F/A-18 Hornet, and eventually the F-35C.

As for a shipboard version, tests are already underway to use a booster rocket to launch LRASM from the missile cells of Vertical Launch Systems such as the Mk41 aboard Aegis destroyers and cruisers. No full up guided tests have been done yet, but booster test launches have.

[youtube https://www.youtube.com/watch?v=kl4ffgPu6qc]

Earlier this week, the third successful LRASM flight from a B-1B took place.

On February 4, the Navy, Air Force and DARPA completed another successful flight test, marking a significant step in maturing key technologies for the future operational weapon system. The joint-service team, known as the  LRASM Deployment Office (LDO), conducted the test to evaluate LRASM’s low-altitude performance and obstacle avoidance as part of the program’s accelerated development effort.

http://www.darpa.mil/uploadedImages/Content/NewsEvents/Releases/2015/LRASMb.jpg

Lockheed and the Navy haven’t released any video of LRASM launches yet, but here’s some JASSM splodey to tide you over.

 

[youtube https://www.youtube.com/watch?v=XBvlm9rZmF0]

Couple Random Thoughts on Anti-Surface Warfare

We linked to this CIMSEC piece on integrating the P-8A Poseidon with a long range anti-ship missile a couple weeks ago.

Anti-Surface Warfare (variously abbreviated either ASuW or SUW) poses a few challenges. For the most part, it is likely to take place at over the horizon ranges. That is, from a surface ship perspective, the radar horizon, limited by the height of the antenna and the curvature of the earth, is fairly short, say 20~25 miles. Ships certainly can detect threat ships at longer ranges via passive measures such as radar warning receivers, such as the SLQ-32 or the SSQ-108(V) Classic Outboard. Passive sensors alert to the presence of a radiating warship, with some fair indication of bearing (~1 degree of accuracy) and some hint of range, based on signal strength. Cooperation between two receivers can generate a fair fix depending on the baseline and environmental factors. Maybe good enough to shoot, but hardly precision targeting.

A real challenge the US faces, especially in the littorals and the Western Pacific is the density of shipping there means that enemy warships will be intermixed with friendly and neutral merchant shipping, requiring a far more precise location, and positive identification of a potential target. As LT Rusty mentioned in the comments here, the surface Navy’s thinking around the turn of the century was that an actual positive Visual Identification (VID) would be required. The obvious problem with that is, anyone close enough to VID a target is likely to get smoked with a quickness.

There are other means of generating that identification. When you think of a radar return, you generally envision a glowing green blip on a dark radar scope. But most radars today convert the raw video to a graphic symbol. Other radars, however, have modes such as Synthetic Aperture Radar (SAR) or Inverse Synthetic Aperture Radar Mode (ISAR) that uses the motion of the radar platform or the motion of the target to artificially act as a much larger antenna. Through advanced signal processing, a three dimensional picture of the target can be derived and displayed, with enough fidelity to make a positive identification.  The P-8A is being equipped with a radar capable of doing this at quite long ranges. Optical sensors capable of extremely fine resolution at long ranges are another option, though whether they are capable of near-real time use is an open question.

Ohio State University Stadium SAR Image

Another problem is SUW is the time of flight for a weapon. During the lag from launch to arrival in the target area, the target itself is moving, and often in an unpredictable manner. The seekers of anti-ship missiles have relatively small fields of view.  A missile might completely fail to acquire a target, or acquire the wrong target, either another ship in an enemy formation, or worse, a completely innocent neutral ship. One of the great shortcomings of our currently fielded Harpoon Block 1C missile is that it is completely fire-and-forget. It goes where it was told before launch, and then starts its own search.  More modern missile (including the Harpoon Block II soon to enter service) can receive updates on the target location during flight, otherwise known as a mid-course update. Of course, that requires the target be carefully tracked by the launch platform or other sensor.

————–

Let’s talk about a missed opportunity.  A few years ago, Raytheon and the Navy had the bright idea to take some of its large inventory of older Standard SM-2 missiles and convert them to a land attack variant, known as SM-4 or LASM (the not terribly original Land Attack Standard Missile). Using a GPS/INS guidance system similar to that on the JDAM precision bomb, the LASM would have been a fairly cheap means of augmenting the striking power of destroyers and cruisers. The program was cancelled before any were fielded to the fleet, apparently for lack of funds, and because the LASM had a rather anemic warhead, one optimized for destroying airplanes, not land targets.

As n0ted in an earlier post, later Burke class destroyers have a limited SUW capability by using their SM-2 missiles against sea targets, rather than their intended air targets. But the semi-active guidance limits them to ships above the radar horizon. A variant of SM-4 with GPS/INS coupled to a anti-radiation seeker derived from the AGM-88 HARM could have given the surface fleet a viable over the horizon ability to at least damage enemy craft, at a relatively low cost.

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The Norwegians Konnsberg seems to nicely fit the bill as a replacement for a Harpoon sized missile.

[youtube https://www.youtube.com/watch?v=bzruKeRKA4c]

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For the foreseeable future, the US Navy’s primary anti-ship platforms will likely remain nuclear attack subs and strike fighter aircraft. And that is, to some extent, fine. They both have some advantages over a surface ship in terms of their abilities to engage, and to avoid engagement.

But as the emerging “distributed lethality” school of thought is beginning to recognize, presenting the enemy with multiple dilemmas (to steal a term from the Army’s current operating concept) has the advantage of forcing him to deal with multiple threats simultaneously, which means almost assuredly one threat is not adequately addressed. Giving tactical strike fighters, maritime patrol aircraft, subs, and the surface navy a viable capability to conduct offensive SUW at long range is itself a form of deterrence that minimizes the chance that the US Navy will ever in fact have to conduct such operations.

Iskandar-M

It’s interesting that the US and Russia, with very different defense requirements and threat scenarios, often end up fielding weapons that, while not mirror images, are at least quite analogous to one another.

When the Army fielded the Multiple Launch Rocket System (MLRS), soon after fielded ATACMS*, in which instead of a pod of six rockets, one pod would carry one large long range Army Tactical Missile System guided semi-ballistic missile.

ATACMS (“Attack ‘ems!”) was first used in Desert Storm to neutralized an Iraqi surface to air missile site.

[youtube https://www.youtube.com/watch?v=-esGSsgLBKI]

The Russians, never slouches in the artillery and tactical missile fields, have two different platforms. They field the Smerch as the counterpart to our MLRS. And they field the 9K720 Iskandar-M short range tactical ballistic missile in place of ATACMS.

[youtube https://www.youtube.com/watch?v=dGCubmnU3ls]

Iskandar has a somewhat longer range, around 500km versus 300km for ATACMS. ATACMS has either a cluster bomblet warhead or a single 500lb warhead, where Iskandar has cluster bomblet, unitary or possibly a nuclear payload, and somewhat larger at that, at around 2000lb.

Both weapons, while flying a semi-ballistic path, are guided throughout the flight, rather than being true ballistic weapons. Inertial navigation with satellite updates (that’s GPS or its Russian cousin GLONASS) gives them excellent accuracy.

Typical targets would be air defense sites, airfields, command and control centers, logistics centers or other similar high value targets.  There are unconfirmed reports that Russia employed Iskandar against a tank depot during its brief war with Georgia over South Ossetia in 2008. The Dutch government concluded that a Dutch national present as a reporter was killed by a fragment from one in the vicinity of Gori.

One reason the US and its NATO allies are concerned about Iskandar-M is that it can reach deep into Western European territories when launched from within Russia. When the US reached an agreement with Poland to install ground based ballistic missile defense on Polish territory, Russia responded by announcing it would station Iskandar launch brigades in the Kalinangrad district, within range of the proposed US installations.  When the US dumped the proposal, the Russians decreed they would not deploy to Kaliningrad. Until eventually they did anyway.

But the real concern is that the Russians have used the launcher vehicle and associated control systems to test and field a new ground launched cruise missile. The missile in question, the R-500, has a reported range of 2000km. That puts Russia in direct violation of the Intermediate Nuclear Forces Treaty of 1987. Of course, in the face of a blatant violation of the treaty, the entirety of the Obama administration’s response was to send a mildly worded letter.

Deep strike missiles such as the ATACMS and Iskandar are a quick response, precise alternative to airstrikes. But they require significant intelligence collection and dissemination to support targeting, and very close coordination with air assets to deconflict airspace. 

 

*After a very protracted development that saw several different names and configurations.

Fox 2!

“Fox 2” is the radio brevity code for the launch of an infrared homing missile… like the AIM-9 Sidewinder.

And the fine folks at Detail&Scale just reminded me that today is the anniversary of the first successful launch of the Sidewinder. Clear back in 1952, the Navy was well on its way to developing a missile that is still in production and use today.

From this:

Photo: Knox posts: for reasons known only to the FB Genie, it didn't post the referenced picture so here it is again....

 

To this:

[youtube https://www.youtube.com/watch?v=1LxhLMiRklQ]

The Navy Needs a New Anti-Ship Missile- Here’s What They Are Looking At.

The Harpoon family of anti-ship missile has been in US service since the late 1970s. At the time of its introduction, it was cutting edge technology in small sized, sea skimming cruise missiles. But today, it is rapidly becoming obsolete.

http://www.sflorg.com/rockets_missiles_spacecrafts/albums/missiles/missiles_02.jpg

Harpoon missile

It’s range of roughly 100 nautical miles is a good deal less than the 150nm minimum that the Navy needs to stand off from enemy missile armed ships. The Harpoon’s radar seeker was pretty advanced when introduced, but today is increasingly vulnerable to jamming or deception. And while the canister launch system is quite compact, ships such as the Flight IIA DDG-51 Burke class destroyers don’t have space for even such a small mount. Ideally, any next generation anti-ship missile will fit inside the existing Mk41 Vertical Launch System that houses all the other missiles these ships carry.

Also, the Navy would like any future Anti-Ship missile to also be able to be carried and launched by existing strike aircraft like the F/A-18 Hornet family, and ideally the F-35C.

Rather than starting from scratch, the Navy has been looking around at what else is already available.

And coincidentally, the Air Force began a replacement for its air launched cruise missiles a few years ago. And the fruits of that program recently entered service as the AGM-158 JASSM, or Joint Air to Surface Standoff Missile.  A longer ranged variant has even more recently entered service as the JASSM-ER, or Extended Range.

(also counts as Daily Dose of Splodey)

Accordingly, the Navy, via DARPA,  has begun developing a variant of the JASSM-ER as a next generation Anti-Ship Missile. This program is known as LRASM, or Long Range Anti-Ship Missile.

Unlike a cruise missile designed to attack targets ashore, Anti-Ship Missiles need to attack moving targets. That means they need an autonomous seeker capability to detect and track the target. Traditionally, this has meant a radar seeker. The Lockheed Martin, the contractor, advertises the seeker as having a multi-mode capability, which, just guessing here, includes a radar seeker, possibly a passive electronic seeker, and most likely an imaging infra-red and possibly a ultraviolet spectrum seeker.

The LRASM is powered by a small jet engine for cruising to the target. But to get it up to flight speed, it needs a rocket booster. To save development costs, the LRASM is using the Mk114 booster rocket currently used by the Vertical Launch ASROC anti-sub weapon.

Leveraging existing weapons and technologies allows for the relatively low risk development of a weapon system that is cheaper than starting from a fresh sheet of paper, and yet still provides a significant improvement in capability over the currently fielded Harpoon family.

The Navy hasn’t made any announcements, but it is quite possible that the LRASM will also be developed into a land attack variant to replace the existing Tomahawk cruise missiles.

Armed Drones at War

It’s not exactly a new idea. I found this video over at DefenseTech.  Not a lot of background on the program, but my guess is it was an attempt to improve Suppression of Enemy Air Defenses capabilities.  Why do I say that? Because most of the targets are mock-ups of fire control radars.

[youtube=http://www.youtube.com/watch?v=aLv9fg93zn8&w=448&h=252&hd=1]

By the way, the article the BQM-34 is firing Mavericks and Shrikes. Do my eyes deceive me? I didn’t see a single Shrike (though, I watched this about 2am…). I saw several Mavericks, early Paveway Laser Guided Bombs, a rocket boosted LGB similar to an AGM-123 Skipper II, and what looked like a short fat version of a GBU-8 HOBOS.  What does my sharp eye observers corps see?

The Standard Missile Family

Almost as soon as the Navy managed to get the 3-T missile family into service (that is, the Talos, Terrier, and Tartar missiles and their associated launchers, guidance radars, and missile control systems), they began to look for ways to improve the actual missiles themselves. The pace of improvements in electronics and solid rocket motors was such that far more effective and reliable  missiles could be built than those already in service. But whatever missiles were built would have to be backwards compatible with existing launchers, handling systems, and missile guidance radars and control systems. The desire to achieve commonality was also present. But the variety of different first generation systems in use meant that while some core components could be common, there would have to be some level of specialization. In the end, the Navy bought a family of similar missiles that shared a basic architecture, and came to be knows as the Standard Missile (no cool nicknames here!).

A bit on missile designations here. US missiles tend to have more than one name or designation, and they can be quite confusing.  The actual missile itself is usually knows by a tri-service designation with a three letter prefix showing its launch platform and purpose, as well as its numerical designation in that sequence, and a suffix letter showing which variant of the basic missile it is. That same missile tends to have a common name as well (in this case Standard is a “proper name”), but even that name may be modified. Even further confusing, the entire system of handling equipment, launchers, radars and control systems may be referred to by a name (and its own designation under a separate tri-service series of designations) that doesn’t quite seem to add up. Finally, the Standard missile family has evolved in  “series” and variants are routinely referred to by those series, i.e. SM-1, SM-2, SM-3, SM-6, and further, especially the SM-2 series has evolved in “Blocks” such as SM-2 Block III.

I’ll try to keep the alphanumeric jargon to a minimum.

Standard SM-1MR Missile

When the move to the Standard missile program began, the long range Talos missile was only in use on a handful of ships, and was considered satisfactory for the time being. Accordingly, the Standard program focused on replacing the medium range Terrier missile, and the short range Tartar missile.

Using an airframe almost identical to the Tartar missile, the first series of Standard missiles came in two varieties, the MR and the ER. The RIM-66(SM-1MR)  was a single stage missile for use on lighter, destroyer sized installations and was a medium range missile. It was used with the Tartar Missile System, and little modification was needed to those Tartar equipped ships. The RIM-67 (SM-1ER) was a virtually identical missile, but was equipped with a solid rocket booster. It was used on ships equipped with the Terrier missile system. Again, few modifications were needed to adapt the ship to the new missile.

Both these missiles in the SM-1 family were semi-active radar guided. That is, the launching ship had radars, looking much like searchlights, that would shine a radar beam on the target. The missile would sense the reflection of this beam off the target, and steer toward it. The missile had to be guided from launch to impact. And ships were limited in the number of these “illuminators” they could carry. Generally, they only had as many illuminators as launch rails, usually two.  Given the limited numbers of missiles they could control, and the limited time for engagement available, a ship could quickly find itself overwhelmed by a “saturation” attack.  The Soviets planned to fire dozens, even hundreds of missiles at shipping targets. If they all arrived at roughly the same time, the defending Navy missile ships would kill some, but in the meantime, many others would strike their targets.

Extending the range of the missile helped some. But it also meant that a longer missile flight tied up illuminator time as well. The ability to cope with saturation attacks was a goal of the Navy for many years.  First the Typon program tried to address it, but it collapsed under its own weight due to technical challenges and exploding costs. The second attempt was the Aegis program. Aegis began as a missile guidance program, but evolved into an entire battlespace management system. The increase in computer power over the 1970s allowed Aegis to succeed where Typhon had failed. But still, even an Aegis cruiser only carries four illuminators. How do you cope with more than four targets at once? The answer is to time-share the illuminators. Aegis was coupled with the SM-2 family of missiles in a way that didn’t require the target to be illuminated throughout the time of flight.

SM-2 ER missiles

With the SM-2 family, the missile would be launched and pointed in the general vicinity of where the interception was expected to take place. The radar system would update the location of the target, the location of the missile, then inject steering commands into the radar signal to steer the missile to the updated intercept point. Only during the last few seconds of the interception would the target need to be illuminated. Thus, four illuminators could handle a vastly greater number of interceptions at one time. As an added benefit, the missile itself was flown along a much more kinematically efficient path, and thus had much greater range, meaning even more time was available for more interceptions.  Older non-Aegis equipped ships armed with the ER missiles were updated under a program known as New Threat Upgrade (NTU) to have a similar capability.

After the first five Aegis cruisers entered service, the Navy switched to the Vertical Launch System to carry guided missiles. Since the missile didn’t have to be guided to the target the entire flight, it didn’t have to be pointed at the target before launch. Instead, the autopilot would steer the missile in the general direction, and the update/terminal guidance process would begin. This had quite a few advantages. First, eliminating mechanical launchers meant a lot less maintenance was needed. Second, for a given volume, a greater number of missiles could be carried. Finally, each “cell” of the VLS could be loaded with any of a variety of missiles, either one of several Standard variants, the Vertical Launch ASROC rocket boosted torpedo, or of course, the Tomahawk land attack missile.  While the cells of the VLS were too small to accept the RIM-67 with its booster, a large diameter, but shorter booster could be fitted, leading to the RIM-156 SM-2ER Blk IV family with an effective range of up to about 130 miles. Not bad, when you consider the original SM-1MR had range of about 15 miles.

SM-2MR on an early Aegis Cruiser
SM-2 ER (RIM-67) and SM-2 ER (RIM-156)

The SM-3 leverages improvements in booster and sustainer motors linked with an all new reaction thrust controlled kinetic kill vehicle to provide an effective anti-missile system against medium and intermediate range ballistic missiles. Planned improvements should give the SM-3 family a viable ability to intercept intercontinental ballistic missiles. This is the missile that will equip the cruisers and destroyers providing a missile shield to Europe under the Obama administration’s deployment plan.

The SM-4 was intended to be a family of land attack missiles using remanufactured earlier missiles with GPS and inertial guidance, but was cancelled.

SM-5 seems to have not been used.

The SM-6 family incorporates the improvements of the later SM-2 missiles with a modified guidance radar from the AIM-120 missile to provide self contained terminal guidance, reducing further the demand for “guide time” from the launching ship’s illuminator radars. It also incorporates an infrared homing system adapted from the Sidewinder missile program.

We mentioned in an earlier post the Standard ARM, using the earlier SM-1 airframe to provide a long range anti-radar missile during the Vietnam War. There was also an “interim” surface launched version of the STARM used on some surface ships, giving a limited anti-ship capability until the Harpoon guided missile was fielded.

The Standard missile family will likely continue to evolve, and there are no plans to replace it in US Navy service in the foreseeable future. Not bad for a weapon system over 45 years old.

ARMs and the Man

A (very) brief history of Anti-Radiation Missiles (ARMs) in US service.

The introduction of Soviet supplied SA-2 Guideline missiles into the air defenses of North Vietnam in 1965 found US Navy and Air Force tactical air power ill equipped to fight in the missile environment.  This is somewhat surprising, as the Navy had a decade of experience with operations missile equipped cruisers and destroyers, and the Air Force had been training with Army Nike-Ajax sites for a similar length of time.  When the North Vietnamese began using SAMs, US planes lacked radar warning receivers, and jamming equipment. Tactics and training to mitigate missile attacks were also lacking. Fortunately, one weapon was already under development to tackle the Guideline threat- the AGM-45 Shrike Anti-Radiation Missile. In this case “radiation” referred to radio-frequency radiation, not the glow-in-the-dark kind.

As soon as the semi-active radar homing technique for missile guidance was developed, designers also realized a weapon could be designed to home in on the enemy radars with a similar seeker. Using the AIM-7 Sparrow missile as a starting point in 1963, by 1965, the Shrike entered Navy service. It shared a similar configuration and size with the Sparrow, but was in fact an entirely new missile airframe.  US Navy A-4 Skyhawks began carrying the Shrike in 1965, and soon it was carried aboard A-6A and later A-7 aircraft.  The Air Force adopted the Shrike in 1966 on board F-105F and eventually F-105G jets.

300px-A4_fires_shrike

The Shrike was a pretty good start, but it suffered from three pretty severe limitations. First, it had a pretty short range. In fact, its best range was less than that of the SA-2 missile that it was designed to defeat. That meant the attacking jet had to enter the engagement zone just to get a shot off. This relatively short range, about 15 miles, was a consequence of the choice of a relatively small missile body. That made it cheaper to buy, easier to carry, and easier to store aboard ship. But it still made life exciting for the crews using it.

Secondly, technology limitations of the time meant that the seeker head could only search for radars in very specific bands of the E/M spectrum. Since there are radars that operate on a wide variety of frequencies, that meant the services had to develop a wide variety of seeker heads for the missile. And if you were over the target and had the wrong seeker head, you were out of luck.

Third, the Shrike was a pretty dumb missile. It guided just fine as long as the radar site it was attacking kept radiating. But it didn’t take the North Vietnamese long to figure out that as soon as they saw a Shrike launch, they could just turn off the radar. The Shrike would go stupid and miss the target. Still, forcing the radar off the air meant it couldn’t guide missiles at the main strike group, and the minute or so it was shut down might be all the time needed for the strike to get in.

Still, something better was wanted.  And so the Navy looked at adapting its SM-1 Standard missile (RIM-66) as an air-launched ARM. The “Standard ARM”, or AGM-78, was a BIG missile. Where a Shrike weighed just under 400 pounds, the STARM weighed in at a whopping 1370 pounds. A bigger missile meant a bigger motor, which meant much greater range. Whereas a Shrike had a range of about 15 miles, the STARM could reach out to 50 miles under optimum conditions, well outside the range of the SA-2.  The bigger missile also had a larger, deadly warhead. Most importantly, the larger size meant there was considerably more room for electronics in the guidance section, so the STARM was equipped with a broad-band seeker head, giving the attacking flight crews much greater flexibility in engaging unexpected targets. Finally, the STARM also had a memory that allowed it to continue to the target even if the radar was shut down. Accuracy was degraded, to be sure, but it was better than nothing.

300px-AGM-78_at_USAF_Museum_2009

Now, these improvements sound great, but they came at a cost. The STARM cost much, much more than the Shrike. Further, while the Shrike could be fired from just about any attack plane in the Navy (the Air Force used dedicated F-105s for the SEAD mission), the longer range of the STARM meant more sophisticated detection and localization of the target was needed, so it had to be launched from a dedicated platform. The Navy modified a handful of A-6A Intruders to A-6B, which were used to carry the STARM. A typical A-6B might take off with a centerline fuel tank, two STARMs on the inboard wing pylons, and two Shrikes on the outboard wing pylons.

The Shrike and the STARM both served through the end of the Vietnam War and continued in service well into the 1980s until they were replaced by the current US anti-radiation missile, the HARM.

But as the 1970s wore on, the number and quality of Soviet radar guided missiles kept increasing. A better anti-radiation missile was needed. Development started on what became the HARM. The challenge was to fit the range, speed, broadband seeker and memory of the STARM into a Shrike sized package that could be carried by a wide variety of strike aircraft. In the end, the designers met the first half of the challenge, but had to settle for a missile considerably larger than the Shrike. Still, the AGM-88 HARM is a lot smaller than the STARM, weighing in at just under 800 pounds. While the Air Force uses it almost exclusively from F-16 jets equipped with the HARM Targeting System (HTS) pod, the Navy operates it from almost every F/A-18, as well as its fleet of EA-6B Prowlers. The “H” in HARM stands for “High speed.” With a speed of well over Mach 2, even at relatively low altitudes, the HARM has an operational range of about 50 miles. It’s broadband seeker can detect and track just about every radar source around.

300px-AGM-88_HARM_on_FA-18C

The HARM has three operating modes- PB, TOO, and SP. PB, or Pre-Briefed is used when the geographic location and electronic characteristics of a target are known before launch.  TOO, or Target Of Opportunity, uses the missile seeker before launch to display a track of active radars near the launching aircraft. The aircrew can select which target is the greatest threat to the strike package, and send a HARM to it. SP, or Self Protection, automatically targets the HARM at any enemy radar that locks on to the launching aircraft.

The HARM entered service in 1985, and as early as 1986 saw use in combat against Libya. It was widely used in Operation Desert Storm, the 1999 air war in the Balkans, and continues in service today. It has been widely exported to NATO and other friendly nations, and has been continuously updated.

On the Cusp of the Century Series

Having read my Continental Air Defense series, you’re now familiar with the Century Series of fighters, starting with the F-100 Super Sabre.

But what was the F-99?

Before the Tri-Service designation system came into being in 1962, the Air Force went through several iterations of naming conventions for missile designations. One of the weirder ones was to number some missiles in the same line as fighter aircraft. In the Air Force eyes, a guided missile was just an unmanned fighter. That lead to the Falcon missile bearing the designation (for a very short time) of F-98. And the only surface to air missile the Air Force operated became the F-99, though it was far more commonly referred to as the BOMARC.

220px-BOMARC_A_Surface-to-Air_Missile

Beginning in 1949, the Air Force sought a long range anti-aircraft guided missile for continental air defense. The contractor, Boeing, partnered with the Michigan Aerospace Research Center (hence BOMARC) to develop a long range, high altitude ramjet powered missile. Development was lengthy, but by 1957 the missile system was ready for production, and entered service in 1959 with the designation IM-99 (intercept missile). After the Tri-Service designation system was put in place, the BOMARC was redesignated the CIM-10.

The BOMARC was launched and boosted to supersonic speeds by a booster rocket, then powered in flight by gasoline fueled ramjet engines. Ramjets were a popular choice for early missiles for the range they gave. Solid rocket fuels were not advanced enough to provide sufficient range. Ramjets had most of the advantages of liquid fueled rockets, without the disadvantage of having to carry oxidizer. But ramjets only work at supersonic speeds. Hence the booster rocket. The “A” model BOMARCs used a liquid fuel booster. The missile was raised from its coffin like shelter to the vertical position, and the booster would then be fueled. That added about 2 minutes to the firing time. Advances in rocketry meant the BOMARC B used a solid fuel booster.  Cruise speed under ramjet power was approximately Mach 2.8 at an altitude of around 60,000 feet.

The BOMARC A had either a 1000 pound conventional warhead, or a 10 kiloton nuclear warhead.  All BOMARC B missiles were armed with the nuclear warhead.

The BOMARC was a long range missile. Very long range. The A model had a range of about 250 miles. The B model had a whopping 400 mile range.

Because of this long range, the BOMARC had an unusual guidance system. The missile would be launched toward a predetermined intercept point, and proceed under auto-pilot. Mid-course guidance was by steering commands directly from the Semi-Automatic Ground Environment. Finally, as the missile closed within 10 miles of the target, it used its own onboard active radar seeker to complete the intercept.

220px-CQM-10B_Bormarc_drone_launch_Vandenberg_1977

At the height of its deployment, there were 14 US BOMARC sites. Canada, tightly interwoven with the US in the continental air defense mission, also operated the BOMARC at  two sites. The Canadian decision to deploy BOMARC was a political one, more than a military one. Craig mentioned the reliable Avro Canada CF-100 Canuck a while back. It’s replacement was intended to be the superb CF-105 Mach 2 interceptor. But rising costs lead to Canada cancelling the project just as it was coming to fruition. In its place, the BOMARC was purchased instead.

Technologically, the BOMARC system was an impressive achievement. The missile flew as advertised, the guidance system was relatively effective and reliable, and 10 kilotons will kill just about any intruding bomber.

The problem was, operationally, the system was something of a flop. Long range guided missiles lack the flexibility of manned interceptors. Most “airspace intrusions” in those days were international airline flights either arriving ahead of or behind schedule.  A manned interceptor such as an F-102 could launch, intercept the bogey, determine if it really was the leading elements of the Red hordes, and attack. A BOMARC, however, couldn’t do that. And blowing up airliners in those days was frowned upon.  Further, BOMARC was useless against the ballistic missiles that were coming to dominate the strategic scene just as it became operational. It soldiered on through the 1960s mostly because it was there, but by 1972, all US and Canadian BOMARC sites had been deactivated.

Over 700 missiles were built. And even though they were not a great success as an air defense asset, they still had life in them. Many were converted to high speed aerial targets, ironically dying at the hands of other anti-aircraft missiles.