The Titan I were the FTS went off?
This launch site damage was permanent. OSTF was never rebuilt. It remains to this day a giant hole in the ground.
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.
The Titan II Missile Launch Complex 374-7 Site was listed in the National Register of Historic Places on February 18, 2000.
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.
So how is the Sea Launch NSS-8 launch failure in jan. 30, 2007 counted. Would this be considered an American launch failure due to partial Boeing ownership? Also wouldn't, okay just checked F9 contains ~20% more propellants than the Zenit. So would it be the second largest US pad explosion? Third going to AC-5?
The fifth Thor test on October 3, 1957, was launched from LC-17A. In a near repeat of Thor 101, the missile lost thrust almost immediately at liftoff, fell back through the launch stand, and exploded. This incident was traced to a failure of the gas generator valve to open.Pad damage was evidently quite minor, as LC-17A hosted the launch of Thor 108 on October 24, only 21 days later.
Stretching to test stand explosions, what about the Titan IV booster (after a redesgin became the srmu) explosion at Edwards AFB? Only 280 tonnes of prop though...
Thanks for adding this one! This was Atlas 106 D and Agena B A2201. I have to date found no photos of the failure or its aftermath. This could have been a more powerful explosion than Atlas-Able, the previous U.S. largest. At the time, Atlas Agena B was the largest, most-powerful U.S. launch vehicle. The next launch from Point Arguello LC 1-1 (later renamed VAFB SLC 3 West) took place on November 22, 1961. It also failed, but not on the pad.
The Thor was built with separate propellant tanks. If it fell back onto the pad in a more or less vertical orientation, the vehicle descended below the pad deck through the center hole, hit the flame deflector and skidded along it, breaking neatly into two parts, one fuel and one oxidizer. One tank would break open below the deck, the other above. The propellants didn't inertially mix as thoroughly as was the case on other pads, such as Atlas. While there was a still large conflagration, the blast effects were less than were seen on other stands.
N-1 5L: The LOX turbopump for engine no. 8 exploded just before liftoff. The rocket managed to clear the tower, at 10 seconds into the flight the KORD system started shutting down 29 of the 30 engines. The rocket crashed on the pad, wiping it out and damaging the second N-1 pad nearby. The photo shows the escape system firing to yank the capsule away from the N-1 as it begins to fall back down onto the pad.
A factor in the rapid repair of the old IRBM and ICBM pads in the 60s was that these were top-priority national programs with unlimited funding, so spare pad hardware was stockpiled. Pad explosions were expected and planned for. Note how launch support equipment was well separated from the pads and protected by concrete blast walls (or the long-vanished 'Blockhouses"). Also, the RP-1 usually burned off quickly, so there usually was not thermal damage to the underlying concrete structure.
Will Space X have to pay the bill for the repairs or is that the responsibility of the CCAFB?
SpaceX clearly thought pad explosions were a thing of the past, since the fueling and other support equipment was located close to the pad
video of pad explosion of Atlas-Centuar AC-5 (video of explosion starts at 2:13)
The final Titan I R&D launch was that of Missile V-4 from VABF's 395-A1 on the evening of May 1, 1963. In an ominous prediction of Atlas 45F five months later, the missile experienced a stuck engine valve that prevented the LR-87 engines from achieving sufficient thrust to lift the 110 ton missile, which then tipped over and exploded on impact with the ground. 395-A1 was repaired in two months and hosted Titan SM-7 on August 15.
Quote from: Chrup4 on 09/03/2016 07:07 amSamos 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.Thanks for adding this one! This was Atlas 106 D and Agena B A2201. I have to date found no photos of the failure or its aftermath. This could have been a more powerful explosion than Atlas-Able, the previous U.S. largest. At the time, Atlas Agena B was the largest, most-powerful U.S. launch vehicle. The next launch from Point Arguello LC 1-1 (later renamed VAFB SLC 3 West) took place on November 22, 1961. It also failed, but not on the pad. - Ed Kyle
I think that a few years ago Joel Powell did an article on Atlas pad crumples. Not all of them went boom. In fact, I think he was more interested in the ones that crumpled but did not explode, because they were not recorded regularly.
An ISDS malfunction caused the loss of the very first Atlas-Agena flown, and you may recall that they had to destroy Mariner 1's booster just before staging occurred since the Range Safety charges on the Agena would then be disabled.
Staging does not disable the upper stage FTS
1. The details on Centaur are less clear. The mission reports for AC-6 indicate that it had an ISDS, but it doesn't seem that it was carried on all launches (certainly not on AC-43 anyway). All Centaurs did have a separate FTS, which was used several times over the years.2. I probably should have phrased that earlier post better since it makes it sound as if the Agena had a separate FTS, which it didn't.
2. That was important for GATV.
Some would argue that GATV wasn't a "real" Agena, but a customized Agena variant
Quote from: Blackstar on 04/08/2017 02:06 amI think that a few years ago Joel Powell did an article on Atlas pad crumples. Not all of them went boom. In fact, I think he was more interested in the ones that crumpled but did not explode, because they were not recorded regularly.Atlas 190D famously crumpled on SLC-4W May 11, 1963 and was recorded on camera, we've all seen than one. The booster intended to launch Mariner 6 also crumpled, but its collapse was averted by two quick-thinking technicians. Atlas collapses also happened a couple of times at operational silo facilities.The Mercury astronauts were in a high risk profession; John Glenn flew when the Atlas was batting .500. Atlas 52D blew up during an operational test from the West Coast only about 24 hours after Glenn's launch. When Gordon Cooper flew at the end of the Mercury program, things didn't get much better; there were four Atlas failures in the first three months of 1963, three of which were D-series (ie. a potential direct problem for Mercury).
The Atlas SLV-3 and Agena D had emerged out of Lewis's proposal for a standardized Atlas-Agena.
They also had different paint jobs on the Agena A/B which seem to indicate the launch location
Hence a bus mission like GAMBIT is going to have a different thermal environment (long term and day/night cycle) vs an ascent mission like Ranger (short duration, sun vs shadow different for each mission)
And no, it wasn't an Air Force initiative. The Kelley Board was a NASA initiative although they did have to get the Air Force's cooperation as they were the official "owner" of Atlas-Agena. Details are all in "A History of Project Ranger" for anyone who wants to read them.
1. But at the same time, not all Agenas were bus missions. For example, some Samos satellites separated from the Agena and only used it for the boost phase, while others used it as a bus, yet they seem to have all had the same paint pattern.2. Edit: I just checked and Midas 2's booster did have a paint pattern closer to that of VAFB Agenas, but also sporting the Thor-Agena checkerboard on white. (Midas 1 had the roll bars). All Air Force Atlas-Agena A/Bs from Samos 2 onward seem to have had the two black dots on white inside a black rectangle.
Standardizing the LVs was probably inevitable anyway once the Atlas ICBM program came to an end.
As for the other point about Ranger not using the Atlas SLV-3/Agena D, the Air Force got priority which resulted in NASA flying Agena Bs for a good two years after DoD launches stopped using them (although Mariner 3/4 used the Agena D). NASA wouldn't have even used Agena at all if they'd had the choice, but Centaur took almost half a decade to become operational.
Ok fair enough. Some of the sources I was using seem to be outdated and predate declassifications. The artist's rendering here does show a Samos still attached to the Agena.
1. What I meant was the Air Force got priority which prevented switching Ranger to them so NASA had to continue using the older Agena Bs that they'd already accumulated. NASA also had budget constraints which did not affect the practically limitless funds available for high priority DoD missions. Now, it's possible that Lockheed were able to fill two orders for Agena Ds to launch Mariner, but all other ones they had were earmarked for Air Force use.2. I doesn't seem logical that they'd continue flying Ranger on the older and less reliable booster models if they'd had the choice. 3. The Air Force didn't use Agena B one second longer than they had to, because they could get the latest and best hardware ahead of NASA. As proof of this, NASA originally intended to use leftover Atlases from cancelled Mercury missions to launch GATVs, but the Gemini program ended up getting enough funds that they scrapped that idea and just bought all-new SLV-3s.
1. Wrong. The only NASA users of Agena B after the introduction of the D model was Ranger and OGO. Mariner, GATV, OAO-1 used the D. The AF still used B for MIDAS
a. If they already bought them
And there were no real "leftover" Atlas D's from Mercury. They were quickly reassigned
Yes as I said, they probably had leftover Agena Bs and possibly lacked the money/scheduling to buy Ds. The statement about MIDAS definitely isn't correct because the last of the original MIDAS series flew in July 1963 one week after GAMBIT made its maiden launch, so MIDAS was ending just as GAMBIT was beginning. There was a second group of MIDASes flown in 1966, but of course those used the SLV-3/Agena D.
They also had different paint jobs on the Agena A/B which seem to indicate the launch location (applying of course to Atlas-Agena since Thor and Titan Agenas were never flown from CC). West Coast Agenas had two dots inside a rectangle while East Coast Agenas had roll bars. Samos 1's Agena was all-white, but they probably hadn't come up with a paint scheme yet. The Agena D did away with this, all of them had a checkerboard pattern.
There's a B&W video of an old Soviet rocket launching, suffering a total engine failure, then falling back into the pad area. Seems every time I find it, it gets removed a short time later. Always wondered about that launch.
Quote from: ZachS09 on 04/12/2017 03:59 amWhen you saw this one video, did you see the strap-on boosters stripping off moments before impact?If so, that would be the 1982 Zenit accident. An old thread here from a couple years ago had identified that video clip as the '82 failure. Otherwise the April 2, 1969 Proton accident is a possibility.In the case of the '88 accident, the core stage engines malfunctioned almost immediately at liftoff, but the booster computer system was blocked from sending a shutoff command until T+20 seconds so as to prevent a pad fallback. When the 20 second mark was reached, the command was unblocked and the core and strap-ons shut down. This turned out to not be enough time to get the booster away from the pad, which was severely damaged. According to a translated document I read, it seems like the core stage suffered a control rather than a propulsion system failure.The same document also noted that the '87 accident would not have been survivable on a manned launch, and apparently necessitated improvements to the Soyuz SAS abort system (at least that's what I could discern from the translated text).
When you saw this one video, did you see the strap-on boosters stripping off moments before impact?
Wow. I'm surprised how it remained mostly intact all the way down. That was surreal.
Emergency shutdown T+28,26 (sec)
Quote from: Alter Sachse on 04/12/2017 05:38 pmEmergency shutdown T+28,26 (sec)I believe the video clip linked here is in fact the 1988 failure, not the '82 one because the entire propulsion system shuts down, not just the core stage.
launch failures (on-pad or near the pad)possibly not completely16.04.1960 (Luna) exploded near the pad01.06.1962 Zenit 2 emergency shutdown T+1,8 sec /fell down 300m next to pad10.07.1963 Zenit 2 emergency shutdown T-1,5 sec /exploded / pad damaged - next launch 10/6318.03.1980 Tselina exploding when refueling / next launch April 1983 ! (43/4)15.05.1982 Zenit 6U failed T+28.26 crashed in the forest (41/1)26.09.1983 Sojus (T10) fire/exploded / next launch 11.06.1984 (1/5)18.06.1987 Resurs ex/pad damaged/next launch 12/88 (43/3)27.07.1988 Resurs fell down 50 m near the pad/pad damaged/ next launch 6/89 (43/4)04.10.1990 Tselina 2 ex T+2,44 sec (45/2)30.01.2007 NSS 8 ex shortly after liftoff (Odyssey)
Was Intelsat 27 to far from the pad to count?
An R-7 ICBM test on July 10, 1958 failed when one strap-on shut down at liftoff and broke away from the stack. The strap-on fell onto the pad while the rest of the vehicle crashed nearby. According to some sources, it carried some of the avionics intended for the Luna 8K72 booster, and the failure was caused by high frequency combustion chamber vibration which would end up being a nagging problem over the next two years.
Are you going to cite your sources or just blatantly cut and paste from wikipedia and bypassing its sources?
Quote from: WallE on 04/12/2017 04:14 amQuote from: ZachS09 on 04/12/2017 03:59 amWhen you saw this one video, did you see the strap-on boosters stripping off moments before impact?If so, that would be the 1982 Zenit accident. An old thread here from a couple years ago had identified that video clip as the '82 failure. Otherwise the April 2, 1969 Proton accident is a possibility.In the case of the '88 accident, the core stage engines malfunctioned almost immediately at liftoff, but the booster computer system was blocked from sending a shutoff command until T+20 seconds so as to prevent a pad fallback. When the 20 second mark was reached, the command was unblocked and the core and strap-ons shut down. This turned out to not be enough time to get the booster away from the pad, which was severely damaged. According to a translated document I read, it seems like the core stage suffered a control rather than a propulsion system failure.The same document also noted that the '87 accident would not have been survivable on a manned launch, and apparently necessitated improvements to the Soyuz SAS abort system (at least that's what I could discern from the translated text).Video clip from the launch failure on 15.05.1982http://www.kosmonavtika.com/lancements/1982/15051982/15051982photos.html
A real on-pad explosion (Nicolas' website) http://www.kosmonavtika.com/lancements/1990/04101990/04101990photos.html4.10.1990 pad 45/2 destroyed and never rebuilt
http://kik-sssr.ru/IP_4_Turatam_old_Razdel_1.htm
Kerolox has this unfortunate property not experienced with other propellant combinations. Hypergols burn on contact, reducing their explosive potential, while hydrolox, in the absence of an ignition source, will merely turn into water vapor if it mixes.
Kerolox also requires an ignition source and would remain O2 and RP-1
Alright, that part is correct. LOX and LH2 should turn into gel when mixed because LOX will do that when it's mixed with any flammable liquid. Most importantly, it turns into a shock-sensitive gel. An ignition source isn't required to set it off, you just have to bump/strike/hit it.
If the LOX had still been present... kaboom.
Not true either.
Quote from: WallE on 04/24/2017 01:42 amKerolox has this unfortunate property not experienced with other propellant combinations. Hypergols burn on contact, reducing their explosive potential, while hydrolox, in the absence of an ignition source, will merely turn into water vapor if it mixes.Wrong, Kerolox and hydrolox have the same issue. if there is no ignition, then hydrolox remain H2 and O2. Kerolox also requires an ignition source and would remain O2 and RP-1 without one. hydrolox has more flammability and lower ignition energy.
Are there any examples of pad failures where hydrolox or LOX + any hydrocarbon mixed together on the pad environment and failed to explode? I'm recalling from some thread here on NSF the rocket scientist maxim that "ignition is free" when it comes to investigating explosion failures.
I can't think of any off the top of my head. I recall various leaks of monoprops & hypergols making a mess on the pad, but not exploding. I'm also not counting the buildup of gaseous hydrogen on the STS pad that was handled with the burnoff system prior to main engine ignition.
Atlas 9C has to be one for the record books since there has never (to my knowledge) been another failure of a US launch vehicle that did this much damage to the pad. .... The umbilical towers and the large service tower were completely flattened. The top portion of the service tower shown here weight about a ton, and it was thrown a few hundred feet by the blast. The concrete launch stand was also caved in.
I wonder how the SpaceX Amos 6 and Antares CRS-3 failures stack up. Both did significant damage.
LOX spills out, and gets ignited by the vernier exhaust.
LOX does not burn
Five pads were in use in 1965. LC- 12,13, 14 and 36 A&B
Two interesting photos. The first one shows the launcher from 576-A2 being "borrowed" to replace PALC 1-1's launcher after Samos 3. When you need a launcher mechanism in a hurry, best way to get one is to steal it, preferably from an inactive pad. The second photo shows the old, burned-out launcher being hauled away. I wonder if they scrapped it, or if it was refurbed. Who knows?
Where did these images come from?
Quote from: Blackstar on 06/12/2017 02:42 amWhere did these images come from?On Flickr. There's a lot of Atlas stuff there. SiloWorld used to be the go-to site for Atlas pics, but it hasn't been updated in years.
Can you be a bit more specific?
As one more pad explosion not yet mentioned, Atlas 19D exploded on 576-A1 at VAFB March 5, 1960 when a fire started during a fuel loading exercise. This brings the Atlas pad explosion tally to five for both the East Coast (9C, 51D, 48D, 11F, and AC-5) and West Coast (19D, 27E, 106D, 45F, and 3F).
Quote from: WallE on 04/08/2017 01:03 amAs one more pad explosion not yet mentioned, Atlas 19D exploded on 576-A1 at VAFB March 5, 1960 when a fire started during a fuel loading exercise. This brings the Atlas pad explosion tally to five for both the East Coast (9C, 51D, 48D, 11F, and AC-5) and West Coast (19D, 27E, 106D, 45F, and 3F).Here is AC-5HACL 02032 Atlas Centaur AC-5 3/2/1965 Launch Failurehttps://www.youtube.com/watch?v=F7kevl_lK_o?t=001
Quote from: Hobbes-22 on 09/03/2016 11:21 amN-1 5L: The LOX turbopump for engine no. 8 exploded just before liftoff. The rocket managed to clear the tower, at 10 seconds into the flight the KORD system started shutting down 29 of the 30 engines. The rocket crashed on the pad, wiping it out and damaging the second N-1 pad nearby. The photo shows the escape system firing to yank the capsule away from the N-1 as it begins to fall back down onto the pad.There were many Soviet pad explosions that were spectacular beyond belief, but the last one to date was the 1990 Zenit disaster. I'm not aware of any happening in the post-Soviet era unless there was a missile test or two at some point.Aside from the Nedelin Catastrophe and N-1 5L, there were numerous R-7s that blew on or near the pad over the years. The very first R-36 launch in 1963 lost thrust at liftoff and fell back onto the pad. Two Kosmos (R-14) boosters blew on the pad in the early 70s, one lost thrust at liftoff, the other caught fire during servicing and killed 9 people.
Looks like a movie about nuclear war breaking out. scarying ! Even more since I can't figure where is the Atlas before the proverbial sh*t hit the fan.
The Antares was destructed by Range Safety action just prior to impacting the pad so the explosive force was significantly lessened.As for the Saturn V, some people like to point out that N-1 5L gave us an idea of what a pad explosion would be like, but they forget that the N-1 didn't have liquid hydrogen on it. AC-5 was examined in studies of a hypothetical Saturn pad explosion although it was a much, much smaller vehicle.AC-5 also didn't really do any major structural damage to LC-36A, it was pretty much just heat damage resulting from the 6000°F temperatures at the center of the LH2 blast and the pad was restored to use in only three months.Also I wish we would see some footage of Samos 3 other than that one video you've all seen a million times. Critical Past did have an extended length version of that showing the smoking pad afterwards. I love this report though. Talk about having a knack for understatement.
The Antares didn't look like it was destroyed by the Range from the medium-range camera.
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.
A couple of more videos surfaced.Atlas Centaur AC-5 Launch Failure 3/2/1965sdasmarchivesPublished on May 28, 2019HACL 02139https://www.youtube.com/watch?v=w98Ij6eFpE4?t=001HACL 02140https://www.youtube.com/watch?v=wkA-CDYTZvI?t=001
Holy hell in the second video it's clear when the liquid burst before the initial fireball.
Lovely high-res video of Titan I C-3. It's too bad we've never seen any aftermath photos of either B-5 or C-3. Also it does seem that footage of the latter is slightly more common--The Right Stuff has the best quality clip of B-5 I've seen.There's a lot of falling debris post-explosion. It looks like wiring harnesses or something.
sciencephoto.com has a Samos 3 launch film taken from the umbilical tower camera. Awesome footage I'd never seen before, just the usual long range video everyone's seen from a camera off the side of the pad. It confirms what I always suspected, which is that the Agena ISDS activated and blew it up. It activates while the fireball is still confined to the base of the Atlas and the propellant tanks haven't even touched off yet.
Quote from: WallE on 08/17/2024 01:23 amsciencephoto.com has a Samos 3 launch film taken from the umbilical tower camera. Awesome footage I'd never seen before, just the usual long range video everyone's seen from a camera off the side of the pad. It confirms what I always suspected, which is that the Agena ISDS activated and blew it up. It activates while the fireball is still confined to the base of the Atlas and the propellant tanks haven't even touched off yet.Link?
I had to do some Google Fue to find it (I think).Here is the link to the NSF picture of that rocket on the padhttps://forum.nasaspaceflight.com/index.php?topic=41073.msg1577811#msg1577811Here is the video I found on sciencephoto.com (a different view than what Walle posted)https://www.sciencephoto.com/media/857104/view
Looking at the tower video from the Samos 3 failure, it is interesting that the base of the Agena blows up after the initial explosion of the Atlas. Not sure what is going on there.
Quote from: Blackstar on 08/18/2024 05:38 pmLooking at the tower video from the Samos 3 failure, it is interesting that the base of the Agena blows up after the initial explosion of the Atlas. Not sure what is going on there.As I mentioned above, my theory is that the shock wave from the Atlas falling back into and impacting the launcher tripped the RSO charges in the interstage section, which were designed to blow up the Agena if a destruct command was issued during the Atlas phase of the launch. This doesn't happen on AC-5 as the Atlas-Centaur destruct system didn't work that way.
The very first Atlas-Agena flight, MIDAS 1, failed when the RSO system inadvertently activated during the coasting period between Atlas SECO and staging so they redesigned it afterward.
MIDAS was a bus satellite that did not separate from the Agena,
The postflight report for AC-6 indicates that an ISDS system was carried but it does not seem to have normally been used on Atlas-Centaur vehicles.
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.
In all fairness an accidental FTS activation is thought to have happened on Delta D241 due to the rupture of the SRB so it is certainly possible that vibration could set it off.