Showing posts with label Missile. Show all posts
Showing posts with label Missile. Show all posts

Friday, November 5, 2021

Hypersonic Missiles -- FGFD: Field Guide to Flying Death

 


Hypersonic missiles recently exploded into the news when China tested their own version of the WMD du jour.

Speed is just one of many ways to classify missiles: from the subsonic Tomahawk cruise missile flying 500mph to the ICBMs breaking free of earth's gravity at more than 15,000 mph.   Hypersonic missiles fall in between at fives times the speed of sound around 4,000mph.  

As with aircraft, speed is not the only measure of missiles. Intercontinental Ballistic Missiles (ICBMs) are very fast, but since ballistic means without power, they follow a very predictable parabolic flight/glide path to target.  They accelerate to 15,000 mph to break free of the atmosphere, then coast over the the north pole to their final destination. The intercept path is very predictable.  

At the other end of the scale, a Tomahawk (or other) subsonic cruise missile flies about the same speed as an airliner at around 500mph. They are very small, very light aircraft that are flown to their target. They can evade, maneuver and fly just feet above the ground and hit a target so accurately they can be flown into a particular car in parking lot.  

Hypersonic missiles fly five times the speed of sound, in the range of 4,000 mph, in powered flight. They can fly high, low, maneuver, and evade just like a subsonic cruise missile, but fly from New York to Los Angeles in 45 minutes.  Planes are very hard to shoot down. A hypersonic missile flies almost twice as fast as the Sidewinder air-to-air missile.  It flies faster than the bullets from every US Army rifle and machine gun, faster than 30mm cannon rounds from the gatling gun on the A-10 Thunderbolt II ground attack fighter.  

If China has operational hypersonic missiles, as recent news reports suggest, they could threaten other nations, including us, with dangerous, nuclear capable missiles.  

If Taiwan becomes Crimea Part II, hypersonic missiles may be the threat that keeps America from defending a nation that has been very loyal to us.  President Obama did nothing to stop Putin from seizing Crimea or invading eastern Ukraine.  President Trump sold out the Kurds in Syria after one phone call from the Turkish President.  Hypersonic missiles might seal the deal that puts Taiwan on the same path as Hong Kong.  

Other entires in Field Guide to Flying Death:

Cruise Missiles

Artillery 

Apache Helicopter 

Mutually Assured Destruction 

Gunships 

Armor piercing ammo 

And then there's the Sam Fender song, Hypersonic Missile

Thursday, June 14, 2018

AIM-9 Explodes on the Test Stand


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AIM-9 Sidewinder missile fired from an F/A-18C

My job in the Air Force was Aging and Surveillance Testing of missiles--everything from the AIM-9 Sidewinder air-to-air missile all the way up to the Minuteman ICBM.
In my Air Force service between 1972 and 75, I never got closer to Viet Nam than the western desert of Utah, but test firing missiles can be dangerous.  My first brush with missile-induced death only caused minor, temporary hair loss.  The second was a lot worse, but more on that later.
On a warm, spring Friday in 1973, we were scheduled to fire 20 AIM-9 Sidewinder missiles in a test stand.  The missile test area was in the northwest corner of Hill Air Force Base, three miles from main base and the airfield. It was also out of the flight path of the two runways, since we could occasionally send up clouds of smoke from test firings that changed from burn to explosion.  Today was one of those days. 
Weeks before the test, we received a shipment of AIM-9s randomly selected by lot number.  We then froze the missiles in a large freezer. We shook them on a vibration table that was a huge 300,000-Watt speaker driver.  We simulated various stratospheric heights in the altitude chamber, then finally took the stressed missiles, bolted them to a test stand, attached accelerometers, and fired them.
On a good day we could fire one every ten minutes, allowing for burn time and time for the spent missile and for spinning the big screws that locked the missile into the test stand. By the time of this test, I had been on the fire crew of several batches of AIM-9s. 
The crew leader was Staff Sergeant John Pachuca.  He would retire the following year with 20 years of service. Hill was his only duty station in more than a decade. In the 60s, missile testing consolidated at Hill. Several other sergeants planned on retiring at Hill.  But this stable environment also meant that promotions were few and far between, so Big John Pachuca would retire a staff sergeant. Before he retired, my muscular Mexican-American crew chief would save my life.  
After each missile was fired, we counted to ten in a ditch several yards away from the concrete test stand. I waited in the trench till the noise stopped, and then vaulted the wall to switch the missile. Two of us ran to the stand and unscrewed the clamps while two more grabbed the next missile.  We used asbestos gloves to carry away the casing of the spent missile. 
The stand was covered with a shelter made from perforated steel planking or PSP. They were more the sheets were ten feet long, fifteen inches wide and weighed more 66 pounds. They were designed to be temporary runways during World War II, but were also great as temporary roadways or to make a cover that allowed smoke to blow through. PSP sheets are full of holes.
Since it was Friday, we all wanted to get done, so we sprinted to get the fired missile out of the stand and the next missile locked in.  When a missile fires, it roars for several seconds then the sound dies away. Each missile has a unique burn time and part of the test was recording that burn time.  Burn time was not my part of the test. The test went well in the morning, but after lunch a few glitches with electronic equipment slowed us down. We wanted to get done and have a weekend off, so we moved as fast as we could bolting the missiles to the stand, then removing the fired missile.  After three firings in the afternoon we had a rhythm again.  The fourth missile fired and burned, but the burn time was about two seconds too short.  I started to vault the wall then suddenly flipped backwards. I thought the top of my head was being torn off. 
I started yelling with pain and swinging wildly. I shut up when I saw the flash of the entire test pad blowing apart.  I looked up and saw a sheet of PSP fly over the ditch we were in. If I had been standing above the ditch, the ten-foot steel sheet would have cut me in half.  John Pachuca had grabbed my by the hair—which was three inches long and barely in Air Force regulations—and thrown me back in the ditch. He knew the burn was too short and heard the sputter before the missile exploded. 
Inside the missile, the propellant cracked during the freezing and shaking. The air gap caused the propellant to stop burning, but then heat in the casing caused the remaining propellant to heat and sizzle.
Then the AIM9 blew up on the pad.
I was lying on back in the ditch with the big sergeant in the white overalls on top of me.  My head hurt for days. Until sundown and much of the next day we cleaned up what we could of the mess. Engineering teams had to rebuild the test stand.  We continued the test the following week.  The test site had another pad because when missiles go high order they blow up everything around them.
The next time a missile test went wrong I wasn’t so lucky. 


Tuesday, April 17, 2018

Field Guide to Flying Death: Cruise Missiles


A British Tornado fighter plane carrying four 
Storm Shadow Cruise Missiles  

Cruise missiles are actually a pilotless jet plane that flies to its target and explodes instead of landing.  Cruise missiles, like the Tomahawk and Storm Shadow missiles the U.S., U.K. and France fired at Syria recently, have jet engines and are in powered flight from launch to target.  

Rocket-Powered Missiles
Most modern missiles are rocket powered. They launch, burn their solid or liquid fuel in the first few seconds or minutes of the flight, and then follow a ballistic path to target—they fly where gravity and air resistance says metal darts coasting at thousands of miles per hour through air will go. They are thrust to a speed of one thousand to several thousand miles per hour then coast to their target using a guidance that steers the missile while it coasts through the air at very high speed. 


Cruise Missiles 
A Cruise missile doesn’t coast through the air, it flies.  Really it is a jet plane with a warhead as its only passenger.  So instead of blasting to thousands of miles an hour then coasting to target with little nudges of guidance, the Cruise missile flies. Because it flies, it can travel hundreds of miles a hundred feet or less above the ground over varied terrain. If the enemy tries to intercept a cruise missile, it can evade. The best fighter planes can only turn, dive or climb within the limits of the pilot’s brain and body. Somewhere above 5gs, even the most fit pilot will black out. The only limit on evasion by a Cruise missile is physics.  

The Storm Shadow and Tomahawk cruise missiles recently fired at Syria are subsonic, traveling 500 mph, or about the same speed as a commercial airliner. But a cruise missile is much harder to hit.  Flying close to the ground, following the terrain, makes it a tough target to hit. Most radar systems don't work that close to the ground.  

A Tomahawk Cruise Missile fired from a U.S. Navy Destroyer

Cruise missiles are so accurate they can hit a garage door after a 500-mile flight. The latest upgrades to the navigation systems make the targeting so good the 3,500-pound, 20-foot-long missile could probably hit the handle on a garage door. 

The Attack on Syria
In the most recent raid, all of the 103 missiles flew to target.  The Syrians claimed to have shot down 71 of the missiles.  NATO said Syria fired 40 missiles to no effect.  The Syrian claim is quite amazing, shooting down 71 missiles with only 40 interceptor missiles. The firing of the missiles was a demonstration of how adaptable these missiles are to different launch sites.  The Storm Shadow missiles were fired from French and British fighter planes. The U.S. Navy launched 57 Tomahawk cruise missiles from destroyers, cruisers and a submarine. The Air Force launched another 19 Tomahawks from B1-B Lancer bombers. 

Plans are underway for a rocket-assist package for the Tomahawk that would increase its speed to Mach 3, more than 2000 mph. Another innovation would be to use unburnt jet fuel as an explosive on impact.  Both innovations would make an already effective weapon even more deadly.

Not So Supreme: A Conference about the Constitution, the Courts and Justice

Hannah Arendt At the end of the first week in March, I went to a conference at Bard College titled: Between Power and Authority: Arendt on t...