Author Topic: On-Pad Explosions  (Read 23310 times)

Offline edkyle99

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On-Pad Explosions
« on: 09/02/2016 07:34 PM »
In light of recent events, here are some previous relatively big on-pad explosions in the U.S. to compare.  Keep in mind that Falcon 9-29/AMOS-6 dwarfs them all.

The first was Atlas 9C with an Able upper stage, which caught fire, collapsed, and exploded during an attempted flight readiness firing at Launch Complex 12 on September 25, 1959.  The pad was out of service for eight months.

 - Ed Kyle
« Last Edit: 09/03/2016 04:19 PM by edkyle99 »

Offline Jim

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Re: On-Pad Explosions
« Reply #1 on: 09/02/2016 07:38 PM »
The Titan I were the FTS went off?

Offline edkyle99

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Re: On-Pad Explosions
« Reply #2 on: 09/02/2016 07:41 PM »
Next was Atlas 51D at LC 13 on March 11, 1960.  It only went seven feet, after the B2 engine suffered combustion instability, before falling back on its pad.  LC 13 would be out of action for seven months.

 - Ed Kyle

Offline edkyle99

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Re: On-Pad Explosions
« Reply #3 on: 09/02/2016 07:46 PM »
The Titan I were the FTS went off?
First came Titan 1 Missile No. B-5, which was released prematurely from LC 19 on August 14, 1959, causing an unplanned umbilical release that killed the engines after 2.87 seconds.  B-5 fell back onto the launch stand and disappeared in a fireball.  The pad was offline for 6 months.       

 - Ed Kyle
« Last Edit: 09/02/2016 07:55 PM by edkyle99 »

Offline edkyle99

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Re: On-Pad Explosions
« Reply #4 on: 09/02/2016 07:52 PM »
The next on-pad explosion was the destruct system issue.  Titan 1 C-3 exploded at LC 16 on December 12, 1959 during a launch attempt.  4.2 seconds after the engines ignited, a launch destruct system relay "chattered" due to vibration, setting off the destruct charges.  Somehow the pad escaped substantial damage so that it hosted a launch only two months later.  Perhaps the destruct system saved the pad from the worst of it.

 - Ed Kyle
« Last Edit: 09/03/2016 01:35 AM by edkyle99 »

Offline edkyle99

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Re: On-Pad Explosions
« Reply #5 on: 09/02/2016 08:06 PM »
Atlas 48D suffered a failure very similar to Atlas 51D.  It flew just a few feet from LC 11 on April 8, 1960 before falling back on its pad after a booster engine suffered combustion instability.  This failure did less damage to the launch pad this time.  LC 11 hosted its next launch only three months later.

Art LeBrun supplied a post-fire photo.

More to come ...

 - Ed Kyle 

« Last Edit: 09/02/2016 09:53 PM by edkyle99 »

Offline IRobot

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Re: On-Pad Explosions
« Reply #6 on: 09/02/2016 08:57 PM »
Atlas Agena D, May 1963.
No bang, but collapse on pad, due to structural failure, as the 2nd stage tanks were emptied.


Offline edkyle99

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Re: On-Pad Explosions
« Reply #7 on: 09/02/2016 09:52 PM »
Combustion instability struck again when Atlas 27E failed at liftoff from Vandenberg AFB 576-F on June 7, 1961.  This was the first Atlas E operational type launch attempt from a coffin launcher.  The result was a nasty failure.  The launch attempt failed immediately when the B-1 chamber lost thrust.  The site suffered heavy damage and was out of service for nine months.

 - Ed Kyle
« Last Edit: 09/02/2016 09:54 PM by edkyle99 »

Offline edkyle99

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Re: On-Pad Explosions
« Reply #8 on: 09/02/2016 10:01 PM »
Atlas 11F blew up upon launched from Cape Canaveral LC 11 on April 9, 1962.  Atlas ignited its engines and began to rise, but suddenly, only a few feet above the launch stand, its sustainer engine turbopump exploded.  11F disappeared in a giant fireball, leaving only scattered remains around a smoking launch pad.  LC 11 would be out of action for four months.  I don't have any photos, but a video of the dramatic failure can be found at Critical Past.
http://www.criticalpast.com/video/65675023307_Atlas-missile11F_Atlantic-Missile-Range_large-explosion_fire-and-smoke

 - Ed Kyle
« Last Edit: 09/02/2016 10:03 PM by edkyle99 »

Offline Graham

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Re: On-Pad Explosions
« Reply #9 on: 09/02/2016 10:07 PM »
I was planning on creating a thread asking about this very thing. Thanks Ed, and of course the late Mr. LeBrun for the pictures and info.
I have loved the stars too fondly to be fearful of the night
- Sarah Williams

Offline edkyle99

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Re: On-Pad Explosions
« Reply #10 on: 09/02/2016 10:13 PM »
The Titan Operational Suitability Test Facility at Vandenberg AFB, was built as a prototype for future operational Strategic Air Command Titan ICBM launch complexes.  It consisted of a 160 foot deep silo complex equipped with a hydraulically driven elevator designed to lift a fully fueled Titan, its launch stand, and its launch umbilical mast to the surface for launch.  Titan 1 missile V-2 was installed in the silo to test the design.  On December 3, 1960, a full wet dress rehearsal was performed using Titan V-2.  The missile was in its silo for the 15 minute LOX loading, then was raised to the surface for final countdown.  After the countdown test was completed the missile tanks were vented and the missile began to be lowered back into the silo where propellant offloading would be performed.  During the lowering process, the elevator failed.  The missile plummeted to the bottom of the silo causing a series of explosions that ejected the 160 ton, multi-story elevator "crib" structure straight up out of the silo.  The two massive silo caps were also tossed aside.  One five-ton piece of the site landed 1,200 feet away.

This launch site damage was permanent.  OSTF was never rebuilt.  It remains to this day a giant hole in the ground.

 - Ed Kyle
« Last Edit: 09/02/2016 10:14 PM by edkyle99 »

Offline Blackstar

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Re: On-Pad Explosions
« Reply #11 on: 09/03/2016 12:24 AM »

This launch site damage was permanent.  OSTF was never rebuilt.  It remains to this day a giant hole in the ground.



I took these a couple of years ago at the site.

Offline edkyle99

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Re: On-Pad Explosions
« Reply #12 on: 09/03/2016 01:33 AM »
Atlas 45F faltered when its B-1 main fuel valve failed to open at liftoff from VAFB 576G on October 4, 1963.  With only one of the two boosters firing, the missile toppled right over on its side and exploded.  The elevator silo pad was damaged, but not as severely as it would have been in the case of a direct fall back.  Another launch took place about 10 weeks later from this site.

SDASM images.

 - Ed Kyle
« Last Edit: 09/03/2016 01:44 AM by edkyle99 »

Offline edkyle99

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Re: On-Pad Explosions
« Reply #13 on: 09/03/2016 01:42 AM »
Atlas 3F repeated the 45F failure, from the very same launch pad, on April 3, 1964.  Again the B-1 main fuel valve failed to open.  Again the rocket toppled and exploded.  This time six months would pass before another launch from 576G.

 - Ed Kyle
« Last Edit: 09/03/2016 01:42 AM by edkyle99 »

Offline edkyle99

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Re: On-Pad Explosions
« Reply #14 on: 09/03/2016 01:57 AM »
Atlas Centaur 5 suffered a sudden main fuel valve closure at T+0.88 seconds during its launch from Cape Canaveral LC 36A on March 2, 1965.  The rocket fell straight back down into the launcher and exploded, creating a mushroom cloud.  It was the largest on-pad explosion at the Cape for more than five decades, until Falcon 9-29/AMOS-6 on September 1, 2016.  LC 36A didn't host another launch for 16 months.

 - Ed Kyle
« Last Edit: 09/03/2016 01:57 AM by edkyle99 »

Online rayleighscatter

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Re: On-Pad Explosions
« Reply #15 on: 09/03/2016 03:36 AM »
In 1980 a Titan II ICBM in Arkansas was struck by a dropped socket wrench socket. The rocket started leaking fuel and several hours later the hypergolic fuel exploded killing an airman as well as destroying the rocket and silo.

Offline russianhalo117

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Re: On-Pad Explosions
« Reply #16 on: 09/03/2016 04:07 AM »
In 1980 a Titan II ICBM in Arkansas was struck by a dropped socket wrench socket. The rocket started leaking fuel and several hours later the hypergolic fuel exploded killing an airman as well as destroying the rocket and silo.
Actually the Silo (LC374-7) survived with some damage on the order of $225,322,670 in 1980 Dollars. The silo was stripped and sealed during decommissioning after USAF decided that the cost to restore to Titan II Service was to great and the scheduled  conversion of all 373 and 374 silos in Arkansas to the Minuteman series was a short time later cancelled by the Regan Administration.
Quote
The Titan II Missile Launch Complex 374-7 Site was listed in the National Register of Historic Places on February 18, 2000.
Titan II Missile Launch Complex 374-7 Background info: http://www.encyclopediaofarkansas.net/encyclopedia/entry-detail.aspx?entryID=2543
Titan II pads (373 and 373 SMS units) In Arkansas: http://www.encyclopediaofarkansas.net/encyclopedia/entry-detail.aspx?entryID=2266
https://www.facebook.com/forbidden.hillcrest/posts/720157944707720
http://themilitarystandard.com/missile/titan2/silo/index.php
https://en.wikipedia.org/wiki/LGM-25C_Titan_II
« Last Edit: 09/03/2016 04:08 AM by russianhalo117 »

Offline Chrup4

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Re: On-Pad Explosions
« Reply #17 on: 09/03/2016 07:07 AM »
Samos 3 exploded on LC 1-1 at PALC on September 9, 1961. A pad umbilical did not detach at liftoff, which caused the Atlas-Agena B to switch from internal to external power. The engines shut down and the Atlas dropped back onto the pad and exploded in a huge fireball, resulting in the total loss of the photoreconnaissance satellite.

Pad damage was evidently not that bad as Samos 4 flew from LC 1-1 only nine weeks later.

Offline Chrup4

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Re: On-Pad Explosions
« Reply #18 on: 09/03/2016 07:16 AM »
The first Thor IRBM lifted from LC-17B at Cape Canaveral on January 26, 1957. Almost immediately at liftoff, the engine shut down and the missile fell back through the launch stand and exploded. It was unclear what caused the failure until a film review of prelaunch preparations showed pad crews dragging a LOX filler hose through a sandy area, thus it was concluded that the LOX became contaminated with foreign debris, resulting in valve failure.

Pad damage was repaired quickly and LC-17B hosted the second Thor test flight in April 1957.

Offline Chrup4

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Re: On-Pad Explosions
« Reply #19 on: 09/03/2016 07:24 AM »
The third Thor IRBM test, Missile 103, never made it off the pad. During prelaunch preparations on May 22, 1957, the LOX tank exploded and for the second time in 5 months, LC-17B had to be repaired and was out of use until the following September.

This incident was traced to a stuck LOX vent valve which allowed tank pressure to build up to the point where it suffered a structural failure, combined with a careless technician who failed to pay attention to a LOX pressure gauge reporting dangerous pressure levels.

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