Atlas Chronology

[Spaceman Spiff]

A lot has been written about the Atlas Missile en Atlas Launch Vehicle, including in these forums. And it deserves it, having played such an important role in the history of rockets and space travel.

There are different ways to look at history. In narrative form, telling the tale from its beginning, its origins, its evolution. Through the eyes of participants, who tell their own stories as they lived them. Through tables of launches and tests. Through technical specifications and their evolution and adaptation.

I have been working lately on presenting the history of the Atlas rocket (or at least a part of it) through chronology, a visual timeline. It puts the events and facts in a different format and, while limiting in certain areas, it gives a different perspective on what happened when. For example, through the timeline I noticed that  from 12 to 17 May 1959 all Cape Canaveral Atlas launch pads (LC-11, LC-12, LC-13 and LC-14) as well as launch pad 576A-2 at Vandenberg Air Force Base had Atlas missiles on them at the same time. Quite impressive.

It is of course a work in progress. Currently I have entered events roughly through April 1961. I will continue to add to it when time allows.

You can find the timeline here :http://www.wayo.be/atlas-rocket-history/

Of course I welcome all corrections, additions, references or other information.

- Michel -

[Spaceman Spiff]

Great info! That second half of 1961 was interesting chronology wise too. No less than 4 days with two launches per day : Aug 23 (101D and 111D), Sep 9 (26E and 106D), Nov 22 (108D and 4F) and Nov 29 (93D and 53D). The year closes out with a salvo of 3 consecutive days with launches : Dec 20 (36E), 21 (6F) and 22 (114D). (All assuming UTC launch times).
That period will be added to the chronology shortly.

[Spaceman Spiff]

After the 48D failure, for the following nine launches, a 4.25 second holddown delay was incorporated in order to verify engine stability before liftoff. Also a second redundant accelerometer was added to the Rough Combustion Cutoff system to increase reliability in case an accelerometer would fail. No booster instabilities were detected in the nine following flight although in the attempted launch of 32D the RCC in the sustainer engine was triggered, the engine was subsequently replaced and 32D had a successful flight. Of course 27E would show that the problem still existed.

I guess the 48D footage would resemble that of 9C which also burned on the pad for some time before exploding. Of course this was during a Flight Readiness Firing and not an actual launch.

[Jim]

9C also produced an incredibly powerful explosion that leveled the entire service tower on LC-12

Umbilical tower.  The Service tower was unaffected.

[Spaceman Spiff]

I read the postflight report for 48D and it gives a fairly detailed description of the events during the attempted launch.

The postflight reports contain a lot of interesting information. Unfortunately I haven't been able to find many of them. DTIC has a few but some are 'released to the public' but the text is not available on-line. Does anybody know another source for them ?
For the Atlas Timeline, after about 95D they are for the moment my only source for operational movements of the missiles (to/from the pad, hangars, etc.)

51D actually should not have lifted from the pad, but the RCC sensor in the B-1 engine was not working so it allowed the missile to be released anyway. The B-1 RCC sensor on 48D wasn't working either but the malfunction occurred in the B-2 so that engine's RCC operated correctly and terminated thrust before lifoff could be achieved.

That explains the reason why they added redundancy to the RCC accelerometers after 48D.

[RIB]

Interestingly enough, Big Joe, an unmanned Mercury prototype, made it through MAX-Q even though, the Atlas failed to stage. No escape tower on that Mercury-Atlas launch either.

[RIB]

 If poor  aerodynamics were the suspected cause of the MA-1 failure, then why did they Big Joe capsule, essentially the same shape as the MA-1 capsule (though lighter) make it through Max-Q? I understand they reshaped the trajectory after MA-1 but weren't the aerodynamic forces on the Big Joe shot essentially the same as the ones on the MA-1 shot. I don't understand how weight would affect the aerodynamics.  I understand the shape of the Mercury Capsule was different than the "standard" Atlas warhead, but I'm assuming that the weight of the Mercury capsule was LESS than the Atlas warhead, given the velocity requirements for an orbital vs a ballistic shot.

[Jim]

Ultimately the blame for the failure lay on Flight Director Walter Williams both for ordering the launch to take place without the LES and for launching it into cloudy weather where the booster couldn't be filmed after the first 20 or so seconds of flight (as well as depriving us of footage of what was probably a pretty cool explosion).

He didn't have the authority to make either of those calls.
A.  Flight Director is not responsible for the vehicle configuration.
b.  Flight Director does not make launch weather calls.  That is the launch director's responsibility.

[Jim]

Also on the topic of MA-3, I can think of at least three other flights that went straight up and didn't pitch over. These were a pair of Thor launches from VAFB in 1959 and an Atlas R/V test in 1968. The Thors failed because some technician forgot to cut a wire holding the programmer tape in place so they never executed the pitch and roll sequence. The Atlas (95F specifically, it had an ABRES TVX vehicle) I'm not sure of the exact reason for the failure, but probably similar circumstances to MA-3.

Delta 59 Intelsat III-1

[WallE]

On the night of June 22, 1961, Cape Canaveral was treated to a spectacular fireworks display as Atlas 17E launched from Pad 11 on an R&D test. The pitch and roll program resulted in a pitchover rate that was 56% too high. At T+79 seconds pitch oscillations caused an increase in LOX tank pressure and at T+97 seconds aerodynamic forces caused collapse of the vernier fairing. This ruptured a hydraulic line and caused loss of hydraulic pressure to the sustainer and verniers. The missile broke up at T+100 seconds due to either structural failure of the propellant tanks caused by loads or aerodynamic heating.

Investigation into the failure found that the pitch gyro motor was running at 84% speed. With this being the fourth Atlas lost to a gyroscope malfunction, it was decided to immediately phase in the Spin Motor Rotation Detection System in all Atlas vehicles which would generate a No Go signal and prevent launch if the gyro motors were not operating properly. One more Atlas failed this way (Missile 102D in 1963) but it was using the old-style "round" autopilot without the SMRD. Three other Atlas missiles in VAFB's inventory were found to be using the same outdated hardware so their gyro canisters were replaced with Project Mercury spares.

No videos of this launch online unfortunately.

[WallE]

Another flight control mishap. Atlas 23D (code name "Lucky Dragon") lifted from Site B-2 at VAFB on May 6, 1960 as an IOC training flight. After a normal engine start and rise-off, the Atlas abruptly flipped upside down at T+21 seconds and did a couple of cartwheels before the RSO sent the destruct command at T+26 seconds. The booster section landed near the Southern Pacific railroad line but missed actually hitting it. Initial postflight analysis found that the pitch gyro motor was non-operational so that missile stability was lost the moment the programmer entered the pitch and roll sequence. The guidance decoder had also failed during the prelaunch countdown so had the flight continued no guidance commands could have been received and the Atlas would have missed its planned target point in the South Pacific.

The ultimate cause of the pitch gyro failure was a flexible cable lead that contacted the metal gyro case and caused a short that burned out the motor. Afterwards the cable leads would be properly insulated. Another case for the SMRD system as prelaunch checks had no way of detecting an nonfunctional gyroscope.

The cause of the guidance failure was thought to be the result of a faulty vacuum tube; after the pulse beacon was recovered, replacement of one tube in it got it working again. The failed tube had cracked and degassed and this was thought to have occurred sometime during ejection of the pulse beacon canister from the missile or on ground impact and there was no indication of degassing while it was powered on.

Video here. That booster section really goes up like a napalm strike when it impacts the ground, there must have been a lot of fuel still in there. One thing that puzzles me is why there's no engine cutoff prior to the RSO destruct. Isn't there normally supposed to be a cutoff and one second delay until destruct?

Edit: My speculation is the missile never got the engine cutoff command due to tumbling; perhaps the RSC receiver antenna was unable to lock onto it

[WallE]

Flight control issues struck again when Atlas 74D (code name "Tiger Skin") lifted from Site B-1 on July 22, 1960 on another IOC test. The pitch and roll program resulted in a pitch angle that was 69% too high. The Atlas continued downrange until missile self-destruction at T+69 seconds. Film coverage of the flight was lost after T+30 seconds due to overcast skies and tracking cameras were unable to record the latter portion of the flight, however it was believed that pitch oscillations during Max Q overstressed the airframe. The failure was attributed either to an improper motor speed of the pitch gyro or excessive gain in the torquer amplifier. Efforts were made to inspect the Atlas inventory at VAFB for proper gyroscope operation and to get the supplier of the gyros (Kearfott) to overview their manufacturing and testing processes.

Video of 74D does not capture the missile failure as noted above but does show the abnormal pitch angle. The initial round of Atlas IOC tests in 1960 went poorly; out of seven launches only one was considered entirely satisfactory, the rest ending in explosions or missing the target by a long distance.

[WallE]

Atlas 5F launched from Pad 11 at Cape Canaveral on the afternoon of December 12, 1961. It was the third F-series test flight. At T+7 seconds the ARMA guidance system issued erroneous SECO/VECO commands but they were not acted upon as the programmer was blocked from receiving a BECO signal until 120 seconds after liftoff and SECO at 200 seconds to prevent a fallback on or around the pad. The missile took off and flew without incident until the SECO/VECO command was unblocked at T+200 seconds and terminated thrust, causing the Mk IV R/V to only impact about 400 miles downrange. A side pod carried by the missile was released and deployed several flares which were sighted.

The accidental engine cutoff commands were due to a malfunction of the ARMA circuitry due to in-flight vibration levels and it would eventually be solved by adding acoustic liner insulation. A similar malfunction had been noted on 27E during its brief flight six months earlier. Atlas 48E over two years later experienced similar accidental cutoff discretes at launch that resulted in premature thrust termination but that was an early production E-series missile that predated the introduction of the acoustic liner.

This newspaper clipping mentions the release of the flares but calls the flight a success and claims it traveled the full 5,000 mile range which it could not have done anyway as 5F was an R&D missile with three telemetry packages and thus too heavy to manage that kind of distance. There's a lot of lies in that press release.

[WallE]

Atlas 7D was the second D-series Atlas test, launched from Pad 14 on the night of May 18-19, 1959 and the second attempt at launching an RVX-2 R/V after the first attempt on 7C miscarried two months ago. It was the first launch from Pad 14 after conversion for Atlas D, which included the construction of a large umbilical tower to support space launches. In addition, the Mercury astronauts, recruited just a little over a month earlier, were invited to watch the vehicle that would eventually take them into orbit. The Atlas's engines lit up and the missile rose into the night sky and steered downrange. Just about a minute into launch and with no prior warning it disappeared into a fireball. Gus Grissom remarked "Are we really gonna get on top of one of those things?" Alan Shepard asked the launch crews what happened. They replied that they didn't know but would study the data to find out.

As it turned out, the failure was not caused by the Atlas itself but the launcher mechanism--study of liftoff film showed that at first missile motion the B-2 hold-down pin did not retract and as the missile lifted it remained in the hold-down position, yanking at the airframe like someone using a crowbar. This caused a four inch gap between the booster thrust barrel and the airframe above it. The airborne helium fill duct was also ruptured, causing loss of tank pressurization gas during ascent. Fuel tank pressure eventually became too low to maintain structural integrity; at T+62 seconds the intermediate bulkhead collapsed from the weight of the LOX tank above it, and the missile exploded two seconds later.

The hold-down pin failure was due to excessive play in the pulley system designed to retract it at launch and failure of the bell crank retaining bolt. Improved maintenance procedures for the launcher were imposed and the retaining bolts replaced with ones made of higher heat treat steel. The problems with the launcher were evidently quickly fixed since Atlas 10D was erected on Pad 14 just fourteen days later. The launcher mechanisms on Atlas pads were normally very reliable and just about never failed on a launch, making this almost a freak occurrence.

The RVX-2 would fly successfully on its third attempt three months later.

[Kyra's kosmos]

Atlas ICBM artist's conception. What can I say, it's my desktop background.

[WallE]

Atlas 51D launched from Pad 13 at Cape Canaveral on the evening of March 10, 1960 on an R&D flight and dramatically ended a streak of almost 20 consecutive successful or mostly successful Atlas launches. The B-1 engine lost thrust almost immediately at liftoff followed by the missile toppling and an explosion that among other things appears to have caused the structural failure of the propellant tanks, which split open and collapsed (in the second photo the Mk. III R/V can be seen falling to the ground after the tank structure crumpled, one of the more bizarre aspects of this failure). The nearly full propellant load spilled out, mixed, and went up in a gigantic fireball that left Pad 13 a charred mess.

The disaster was found to be the result of rough combustion that caused an explosion in the B-1 engine injector head, badly damaging it and rupturing the LOX dome above. A major fire and explosion then caused the loss of the missile only three seconds after launch. Pad 13 was put out of use for six months, after which it was converted for Atlas E tests and not used for D-series vehicles again (until 1963 when it was converted to an Atlas-Agena pad). Nobody predicted the same failure mode would strike again in just a few weeks and put another launch complex out of use for a while.

The booster engines did have RCC (Rough Combustion Cutoff) sensors designed to shut them down prior to liftoff if this happened, but as it turned out the B-1 RCC on 51D was not working and so the missile was allowed to lift and produce a pad fallback.

The cause of the rough combustion was never precisely nailed down, but several fixes were implemented including installing copper baffles in the booster injector heads to prevent rough combustion and the lessons learned here were later applied to the Saturn F-1 engines.

[WallE]

SAMOS 4 launched on Atlas 108D and Agena 2202 at slightly past noon on November 22, 1961 from PALC 1-1 at VAFB. The pad was quickly restored to use from the SAMOS 3 explosion and back online by October 29, after which 108D was erected. Despite extensive efforts to ensure mission success such as checks for faulty transistors and making sure all plumbing was clean and free of contamination, the result was another (less spectacular) failure. The Atlas rose into a clear, sunny autumn sky and steered downrange--the first problem happened with a BECO at T+133 seconds, eight seconds earlier than planned. Pitch control was lost at T+244 seconds and the Atlas pitched up about 4.7 degrees from nominal. This prevented the guidance antenna from locking onto ground guidance and the programmed SECO signal at T+259 seconds was not received. Sustainer shutdown at T+289 seconds occurred as a result of LOX depletion. At Agena staging the Atlas had pitched up about 160 degrees and as a result of the improper flight trajectory the Agena was pointed downward and backward from nominal and orbit was not achieved. The Agena and satellite impacted at an unknown point in the Pacific.

The premature BECO was found to be the result of locating the staging backup accelerometer (the purpose of it was to send a backup BECO if the programmer failed to do so) on the side of the LOX tank where it malfunctioned from the extremely cold environment there. This same malfunction had occurred during the launch of Ranger 2 a few days earlier and was solved by moving the accelerometer to the fuel tank. The main problem that resulted in loss of the mission was the pitch control issue which was found to be caused by in-flight loss of the heat shield over the retrorockets, exposing the gyroscope package to aerodynamic heating. The heat shield covers were redesigned afterward as well as replacement of transistors in the gyroscope signal amplifier with a type that was not as prone to overheating.

Tracking film showed an object falling from the booster at T+45 seconds which was thought to be the retrorocket heat shield breaking off.

In addition, SAMOS 4 was the first top secret DoD space launch while prior ones were publicly acknowledged. From this point onward the Air Force said nothing in press releases outside a satellite being launched into orbit, which was all that was announced for SAMOS 4 but since the press release also left out the "launched into orbit" part, it was quickly apparent that the launch had not been a success.

Should add that this goes back to a point I made in the Ferret thread about the lack of standardized booster hardware prior to the SLV cores and the reliability issues caused by that. For example it seems only 108D and 111D had a staging accelerometer put on the LOX tank where it would malfunction in this way, I have not heard of this happening on other Atlas vehicles. Same also seems to apply to the retrorocket heat shields.

[WallE]

RM-20/P72-2 aka another unlucky package of scientific test equipment much like the MPRV lost in the 9-65 Thor mishap launched on Atlas 71F on April 13, 1975 from PALC 1-1 at VAFB--after a decade as a TAT Thor-Agena pad, the facility was once again hosting Atlas launches and 71F, once an on-duty ICBM at Dyess AFB in Texas, was mated with a Thiokol Star-17A solid upper stage for this mission, and it was in trouble almost immediately at liftoff as a malfunction of a water valve prevented the flame bucket from being hosed down with deluge water. Propellant overflow prior to engine start pooled in the flame bucket and formed a kerolox glob, causing an explosion. This was registered on the vertical accerometer as a shock. In addition an electrical umbilical supplying power to the booster T/M pulled out prematurely and before it could be cycled to internal power, causing an instant loss of power to the T/M system. As a result no data was returned during the launch and an indeterminate degree of thrust section damage resulted from the kerolox explosion.

The Atlas took off and flew and booster jettison was completed properly but the sustainer and verniers shut down some time later and the Range Safety officer sent the destruct command at T+303 seconds. Owing to the T/M loss it was not possible to determine exactly what caused the propulsion shutdown, but it was probably a leak in some system, perhaps a loss of control gas to the sustainer propellant feed system.

Several changes made as a result of the mishap included re-coating the flame bucket on PALC 1-1 to remove cracks and pits where propellant could pool in, an improved water deluge system, eliminating the practice of draining propellant overflow into the flame bucket, and adding a nitrogen purge system to the booster thrust section to prevent fire damage at liftoff.



Film footage of 71F's launch. The normal speed film at the start shows that it was a quite violent explosion, it actually caused the camera to shake and the pad is on fire for a bit afterward. One is almost surprised the booster was able to lift and fly after that.

[WallE]

Atlas 102F takes off from 576-A1 on a successful launch of a RADCAT radar calibration satellite and a Radsat scientific satellite  for the Air Force Space Experiment Support Program, October 2, 1972. The Atlas, formerly an ICBM stationed at Walker AFB in New Mexico, was topped with a Thiokol/Boeing Burner-2 solid stage. Many refurbed Atlas E/F missiles would fly over the 70s-80s launching payloads of various kinds, including a few spectacular failures as well as the final Agena stage ever flown. Among the modifications made to the vehicles included replacing the ARMA inertial guidance system with an Atlas-Agena Mod III-G radio guidance system and standardized range safety and electrical systems--there had been a lot of E/F missiles built and over the production run there were many changes to the missile hardware as the design evolved or due to findings from failed launches so they could often have considerably different hardware in them; it was considered pertinent that each vehicle have a single, standardized electrical system.

This was the second attempt at launching a RADCAT and it remained in orbit until 2012; the first had been on an Atlas SLV vehicle with a Burner-2 in 1968. That launch was part of a "grab bag" that had 13 different payloads on it all scientific or calibration targets of various types; the payload fairing did not separate and the satellites fell back into the atmosphere and broke up.

[WallE]

Atlas 26E lifted from Pad 13 at Cape Canaveral on the night of September 10, 1961 as part of an R&D launch carrying a Mk III R/V. The flight was entirely normal up until booster jettison at T+129 seconds when the sustainer engine inexplicably shut down. With nothing but the two small verniers for power, the Atlas tumbled its way on down to an impact point about 500 nm downrange instead of the planned lob into the South Atlantic over 3,000 miles downrange and separation of the R/V was not accomplished. What caused the loss of sustainer thrust was not clear as the shutdown occurred during the normal two second data blackout caused by exhaust gases impinging on the T/M antenna during the staging sequence. When the data resumed, the sustainer was not only not operating, but its gas generator was recording temperatures in excess of 1000°F, the result of an apparent LOX-rich shutdown.

GD/A engineer Ed Hujsak suggested that the propellant disconnect lines in the booster section of E/F series missiles could allow propellant to pool in them and be ignited by the sustainer exhaust at booster jettison, possibly damaging components in the missile. He noted that on prior E/F launches there had often been a momentary pitching motion of the missile at staging that could be oscillation caused by exploding propellant and suggested adding cutoff valves to the booster section to prevent leftover propellant from escaping and being ignited.

During booster phase there was an unusual rise in thrust section temperatures beginning at T+77 seconds that eventually reached 115°F at T+115 seconds and stabilized there. The cause of this was unknown and it was not thought to have any connection with the subsequent loss of the missile.

The Air Force in their infinite wisdom then decreed that only cutoff valves for the LOX lines would be added as it was impossible for leaking RP-1 to explode in the absence of LOX.  On December 21, Atlas 6F launched from Pad 11 in an attempt to finish the mission that Atlas 32E had failed to do a month earlier, which was fly a monkey in a pressurized capsule on a suborbital lob. Once again the Atlas performed normally through booster phase, after staging the sustainer hydraulic system developed a leak and eventually engine gimbaling control was lost. The sustainer shut down from fuel starvation caused by missile tumbling and the capsule, containing a monkey named Scatback, separated and landed in the South Atlantic but could not be found as the tracking beacon failed to operate.

The Air Force then finally accepted that the fuel lines on the E/F missiles needed cutoff valves as well and no more mysterious system failures during booster jettison occurred after this modification was done.

[WallE]

Atlas 114D/Agena 2203 (code name "Ocean Way") launched from PALC 1-1 on the morning of December 22, 1961 on the fifth SAMOS attempt, with so far only SAMOS 2 last January having achieved limited success. The launch went nominally until ground guidance sent the programmed SECO discrete at T+265 seconds, but the programmer did not act upon it. The sustainer engine gradually lost thrust due to LOX depletion and the backup SECO cutoff command was not acted upon either. The programmed signal to disable the Agena ISDS, which normally occurred at SECO, was accomplished by a backup signal at VECO. The satellite vehicle was thus boosted into an overly high 350x125 mile orbit that prevented proper deorbit and recovery of the film capsule, which was believed lost somewhere in Canada. As with SAMOS 4, the Air Force did not say anything in their official statement about SAMOS 5 other than that a satellite had been launched on an Atlas-Agena vehicle, although unlike with 4 the announcement did include the remark that it reached orbit.

The programmer was thought to have an open circuit somewhere that caused the non-response to the SECO discrete, but all other programmer functions were accomplished properly. On subsequent Atlas vehicles a modification was done to provide an independent circuit path for engine cutoff in the event of an open circuit.

Other minor problems on the launch included high thrust section temperatures during booster phase, the cause of which was unknown. The B-2 nacelle door failed to properly close at liftoff and remained so to the limits of camera coverage. The nacelle door remaining open probably did not contribute to the elevated thrust section temperatures, but it could not be entirely ruled out and subsequent flights would have increased temperature measurements in them. There was pronounced in-flight vibration during the last 49 seconds of booster phase which had not occurred on any previous Atlas-Agena launch. Although no detrimental effects resulted, this was corrected by moving the gyro package to a different location on subsequent vehicles.

Side note: At the top of the umbilical tower on PALC 1-1 is a camera designed to get a close-up view of the Agena at liftoff. This camera was not present for the first two SAMOS launches as photos of those show and seems to have been added at some point during the spring or summer of 1961 and PALC 1-2 also sported an umbilical tower camera. It was more likely than not added as a result of the postflight findings from SAMOS 1 so they could get a better look at the Agena umbilicals at liftoff.

[WallE]

This wwas part of a doc explaining modifications to the Atlas for MIDAS/SAMOS, which were relatively few--the vehicle was mostly a stock D-series Atlas with increased LOX tank thickness to support the weight of the Agena, and as with all SLV Atlases only one telemetry package with a relatively small number of booster operating parameters monitored (as well as the range safety system being modified to also destruct the Agena if activated). I would assume NASA Atlas-Agenas were similar aside from having the Mod III-G guidance system used for AMR launches instead of the PMR Mod II-A. The standardized SLV-3 core started being phased in during 1963 but Atlas-Centaur did not start using it until AC-13 in '67.

The part shown here explains in detail how GD/A postflight reports were issued and that they were "stepped", starting with a quick flash report within a few hours hours of the launch and progressing through more detailed ones until the final flight evaluation report issued two weeks after the launch. Lockheed of course would have issued their own entirely separate postflight reports for Agena performance.

Of the flash reports we've seen quite a few of those, there's a large collection on Jonathan's Space Report for VAFB Atlas launches (as well as Thor and Scout launches) but no Cape Canaveral ones and they're one page sheets detailing the basic facts of the launch. There are also a number of 7 day reports on DTIC but only for Cape Canaveral launches and the only two week full flight evaluation report I'd seen was for Atlas 48D. NASA also began drafting their own launch reports in 1964 and NTRS has various of those, which appear to contain very similar data to the flight evaluation reports.

[Jim]

NASA also began drafting their own launch reports in 1964 and NTRS has various of those, which appear to contain very similar data to the flight evaluation reports.

When Goddard to over launch management.

[Jim]

[quote author=WallE link=topic=46681.msg2713665#msg2713665 date=1756572993

Of the 24 hour reports we've seen quite a few of those, there's a large collection online for VAFB Atlas launches but no Cape Canaveral ones. There are also a number of 7 day reports on DTIC but all for Cape Canaveral launches and the only full flight evaluation report I'd seen was for Atlas 48D.
[/quote]

There are Flight Test Reports for the ICBMs.

[WallE]

Those are I think all the Flight Test Working Group reports on DTIC mostly for Atlas D/E/F test flights and also the reports for MA-1 and MA-5. Those would be the 7 day reports mentioned above. Of the full 2 week flight evaluation reports however the only one online is for 48D. Those included among other things photographs and telemetry data charts and the later NASA reports also include most of that data (the NASA report for AC-5 definitely did).

[WallE]

re: Atlas-Agena vehicles. Officially this was known as the LV-3 and as I said was mostly a standard D-series Atlas with thicker LOX tank skin and the Mod III-G/II-A guidance system which was a transistorized version of the guidance system used on Atlas D missiles.

The SLV-3 core would eventually replace this for all SLV Atlases. This started out as the Atlas-Centaur core and it had the enhanced MA-5 engines and thicker LOX and fuel tank skin. SLV-3 vehicles also got rid of the retrorockets at the top of the equipment pods that were used to back the sustainer section away from the upper stage/payload after SECO. An important distinction is that early Atlas-Centaur vehicles used the LV-3C designation and still had the retrorockets as well as the xxxD serial number system instead of the SLV-3's numeric only serial numbers. Beginning with AC-13 they were renamed SLV-3C and got rid of the retrorockets.

The first "proper" SLV-3 with no retrorockets was used on the tenth GAMBIT launch in 1964. NASA first used SLV-3 vehicles for GATV but other NASA Atlas-Agena launches used the older LV-3 core through '65.

It gets more confusing because MA-5 was used as a blanket designation for the engines on space launcher Atlases, even when it wasn't. Mercury-Atlas vehicles were referred to as using MA-5 engines although they just used the MA-2 engines (but with vernier solo mode deleted) and the same applied to LV-3 Atlas-Agenas.

Other than that, the SLV-3 core on Atlas-Agena vehicles differed from Centaur ones mainly in having a tapered forward end and the Mod III-G radio guidance system instead of Centaur's inertial guidance.

[Jim]

re: Atlas-Agena vehicles. Officially this was known as the LV-3 and as I said was mostly a standard D-series Atlas with thicker LOX tank skin and the Mod III-G/II-A guidance system which was a transistorized version of the guidance system used on Atlas D missiles.

Agena LV-3A
Mercury LV-3B
Centaur LV-3C

[Jim]

It gets more confusing because MA-5 was used as a blanket designation for the engines on space launcher Atlases, even when it wasn't. Mercury-Atlas vehicles were referred to as using MA-5 engines although they just used the MA-2 engines (but with vernier solo mode deleted) and the same applied to LV-3 Atlas-Agenas.

Uprated MA-2
Atlas D-Agena A (LV-3A)
Atlas D-Agena B (LV-3A)

MA-5
Atlas D-Agena D (LV-3A)
Atlas D-Mercury (LV-3B)
Atlas D-Centaur (LV-3C)

[WallE]

1:15

Could he be referring to CANYON 4 there? If he started in '64 then surely he can't be talking about MA-3 when he mentions an Atlas that went straight up and didn't pitch over.

The Peter Hunter photo collection had had a document listing all Atlas flight failures and the cause of them, but I suspect now that there was a mistake in there and they got the ones for 95F and CANYON 4 mixed up. It listed 95F as failing to execute its pitch and roll program, but CANYON 4 as "Sustainer Mod 3. turbine failure." Seems the latter was actually the one that didn't pitch over and kept going straight up and 95F had the sustainer gas generator failure.

From the video it seems a tech made an ill-conceived adjustment that apparently did something to the booster engine acutators and prevented them from being able to gimbal the engines. In that case the result would be no pitchover maneuver. If so then it would also explain why NASA launched AC-26 with no serious delay, if it was established that the failure on CANYON 4 was just a tech's careless mistake and there was nothing to be concerned about.

[WallE]

Atlas-Centaur AC-3 was the third Centaur R&D test flight, launched June 30, 1964. Atlas 135D was erected on LC-36A January 27 and Centaur 1C February 20. An initial launch attempt June 26 was called off due to guidance system problems. At 9:00 AM on the morning of June 30, AC-3 was launched. Booster performance was almost entirely normal throughout Atlas phase except for a malfunction of the propellant utilization system--for the first 70 seconds of the launch the sustainer engine ran slightly LOX rich. At 70 seconds the PU system abruptly returned the propellant mix to normal. Sustainer thrust however remained at essentially normal levels throughout powered flight. An electrical short was believed to have caused the PU malfunction and had it continued an early SECO from LOX depletion could have resulted. BECO occurred T+147 seconds and SECO T+226 seconds. The Azusa tracking system ceased operating about 30 seconds into the launch; this was due to the addition of an RF shield between the tracking beacon and its power supply which apparently contacted a terminal and caused a short.

The Centaur insulation panels were jettisoned properly at T+177 seconds, thus accomplishing one of the main goals of the launch and vindicating the hard-won effort over the last two years to design a workable separation mechanism. A detachable payload fairing was carried for the first time and it was jettisoned successfully at T+202 seconds. The fairing separation aroused some concern due to momentary high vibration that affected the guidance system. Separation of the Centaur from the Atlas was also successfully accomplished and did not repeat an incident that occurred during staging on AC-2 when Centaur attitude control was lost for a few moments due to an improper umbilical disconnect. Engine start began T+242 seconds.

Five seconds into Centaur burn, hydraulic pressure for the C-2 engine abruptly fell to zero and gimbaling control was lost. This left the C-1 engine to perform attitude control. Pitch and yaw stability were maintained but roll control was lost. The Centaur developed an initially relatively low roll rate of 15 degrees per second but this gradually increased to as much as 40 degrees per second. A programmed pitch-up command at 432 seconds removed any further ability of the C-1 to control the roll rate and it reached 310 degrees per second by 496 seconds. The centrifugal force of the roll forced the LOX in the main tank away from the pump inlets and resulted in engine shutdown from LOX starvation. The programmed MECO discrete at 619 seconds closed the propellant valves and halted residual thrust from venting gases. Attempts at test-operating the boost pumps were mostly unsuccessful due to vehicle tumbling. Operation of the small attitude control engines was successful in arresting the roll rate. Impact of the Centaur in the South Atlantic occurred 12 minutes after liftoff.

The hydraulic system failure was believed due to a break in the connection between the turbopump gearbox and the hydraulic pump. Despite the failure of the Centaur to attain orbit, the launch was considered relatively successful and several important goals were accomplished, in particular verifying the operability of the insulation panel jettison system.

[Jim]

NASA also used mostly Agena B boosters through 1965 but the Mars '64 probes flew on Agena D as the mission requirements needed enhanced performance.

no, the B was not available for the Mars '64 contract

They were also forced to launch Mariner 4 from Pad 12 due to scheduling conflicts although that was normally set up for Agena B launches.

No, two pads were required to launch two probes in the short launch period

Wonder if there were any issues with the flame bucket on Pad 12 not being equipped for the more powerful MA-5 engine thrust?

it was equipped. Many other MA-5 launches occurred from there.

[WallE]

Atlas 7112 ("White Pine") launched from PALC 1-2 on July 12, 1965 to launch the 20th GAMBIT satellite (the Atlas S/N and the launch date are an amusing coincidence). The launch went entirely according to plan until BECO at T+131 seconds at which point the programmer sent simultaneous BECO and SECO commands and advanced its timer to T+400 seconds, terminating thrust. This triggered a premature Agena separation and engine start. Unfortunately the altitude and velocity were too low for orbital insertion to be possible. The Agena burned all the way to propellant depletion but it was hopeless and the stage and satellite vehicle impacted in the Pacific Ocean northwest of Samoa, about 4,700 miles downrange. Postflight investigation believed that vibration caused by BECO had triggered a switch in the programmer that generated an erroneous SECO. Several components were redesigned afterward and dipped conformal coated PCBs would be abandoned.

The transistorized "square" Atlas programmer was a tough beast to tame especially considering the old electromechanical "round" autopilot had been super reliable and as we see here was still causing problems as late as 1965.

[WallE]

If poor  aerodynamics were the suspected cause of the MA-1 failure, then why did they Big Joe capsule, essentially the same shape as the MA-1 capsule (though lighter) make it through Max-Q? I understand they reshaped the trajectory after MA-1 but weren't the aerodynamic forces on the Big Joe shot essentially the same as the ones on the MA-1 shot. I don't understand how weight would affect the aerodynamics.  I understand the shape of the Mercury Capsule was different than the "standard" Atlas warhead, but I'm assuming that the weight of the Mercury capsule was LESS than the Atlas warhead, given the velocity requirements for an orbital vs a ballistic shot.

I found out the answer. Turns out that in fact Big Joe (and its backup vehicle Atlas 20D) had both thicker fuel and LOX tank skin and then on MA-1 they inexplicably went back to using the thinner Atlas ICBM LOX tank skin. In addition, 67D, which launched MA-2, and 77D, which would have launched MA-3, were built this way. They put a reinforcing band on 67D and 77D was recalled and not flown.

[WallE]

Guess there were no changes to the LV-3A propulsion system after all and it was just the standard Atlas D ICBM engines. This also describes vehicles 29D, 45D, 75D, and 84D as assigned for the MIDAS program. Obviously MIDAS did get moved to VAFB after the second launch and most likely because Pad 14 was completely turned over to the Mercury program. 75D did end up launching MIDAS 9 long afterwards in July '63 and it seems a bit strange that the vehicle sat in storage for so long while MIDAS 3-8 used higher numbered boosters built later. 84D ended up not a space booster at all but an on-duty missile at Offutt AFB and launched September '63 in a very late Atlas operational test from VAFB.

Second MIDAS 3 launch attempt: An ominous sign of things to come.

This was the first Atlas-Agena B launch and booster performance was normal despite the satellite failing not long after reaching orbit. Although not mentioned here, the programmer reset itself after BECO which had no real effect on anything but NASA asked the Air Force to look into it just in case. It was apparently an open circuit somewhere and judged a random Q/C fault that the more tightly controlled Mercury program should not have to worry about.

NASA were also a little unhappy that it had taken so long to fly this LV combination as they assumed the Air Force would fly it first and obtain data for them on its performance. Instead, Ranger 1 went up a few weeks later with just one previous Atlas-Agena B launch--the Ranger program had ended up progressing quickly while MIDAS/SAMOS were beset with endless delays which was why it took so long.

[WallE]

Atlas 12D (Tall Fellow) was the first West Coast Atlas launch. It lifted from Pad A-2 on the morning of September 9, 1959, six hours after Big Joe's launch at Cape Canaveral. The flight was an essentially flawless one and impact of the blunt-nosed R/V in the South Pacific occurred nearly on target. However, T/M data was lost from T+112 to 194 seconds due to an apparent short in a wiring harness, preventing evaluation of missile performance during that portion of the flight. The Atlas 9C disaster on September 24 notwithstanding, the second half of 1959 and the first two months of 1960 saw an overall excellent run of Atlas flights with only minor hardware glitches. One other launch occurred in September '59, 17D which launched from Pad 13 at the Cape on the 17th. This one was also trouble free except for another recurrence of telemetry issues during portions of the flight, in this case due to a power supply problem.

[Blackstar]

It would be great if we had a source for all these assertions about why launches failed.

[Jim]

It would be great if we had a source for all these assertions about why launches failed.

Like the like full documents of  accident report or flight test report attached to each post vs clips?

[Blackstar]

It would be great if we had a source for all these assertions about why launches failed.

Like the like full documents of  accident report or flight test report attached to each post vs clips?

Anything. Anything at all.

[WallE]

Oh, this was from the Atlas instrumentation difficulties doc which you can get from DTIC.

[WallE]

Atlas-Able 2 was launched on Atlas 80D from Pad 12 on September 25, 1960, a year and a day since the 9C disaster demolished the pad and put it out of use for eight months. Aside from restoring Pad 12, now with only a small umbilical mast instead of the large tower that got knocked over on 9/24/59, it had taken a long time before another Atlas vehicle was available to fly. 80D was sixty vehicle #s ahead of 20D which had launched the first Able attempt the previous November and unlike 20D, a recycled Mercury booster, it was a mostly stock D-series Atlas with vernier solo mode and only a few small changes to support the use of upper stages. The lunar probe was mostly similar to the Able 1 probe.

The Atlas began its journey from the GD/A plant in San Diego to Florida August 12, the same day that Pad 12 hosted the mostly successful R&D flight of Atlas 66D. It was erected on the pad September 2. The probe arrived September 6. The approach of Hurricane Donna on the 10th necessitated removing the booster from Pad 12 and Missiles 76D, 79D, and 3E on adjacent pads. The Atlas was re-stacked on Pad 12 and prelaunch preparations continued. The probe was heat sterilized on the 22nd to prevent possible contamination of the Moon with microbes. There was no PFRF for this vehicle like the one that led to the loss of 9C; PFRFs had mostly been discontinued on D-series vehicles for a year now.

At 10:13 AM on the morning of the 25th, the Atlas was launched. Engine start and vehicle rise-off were normal and it began steering downrange. The booster was visible until disappearing behind clouds at 90 seconds. BECO occurred at 134 seconds, payload fairing jettison at 170 seconds, and SECO at 271 seconds. At about 14 minutes after liftoff, all tracking and telemetry data was lost. Something had gone very wrong. An initial analysis of telemetry found that the malfunction had occurred entirely in the Able second stage, apparently the AJ10 engine and interstage section. Atlas performance during powered flight had been normal and uneventful, except that the booster failed to act on the programmed VECO discrete; vernier solo mode was only planned for five seconds on this flight but ended up burning until propellant depletion nearly 20 seconds later. This added 100 extra miles of trajectory, but that alone was not enough to be detrimental to the flight.

Due to the late VECO, staging was initiated by a backup signal from an oxidizer valve switch in the second stage, which was set to activate when the valve was 80% open. The intention was that the Able engine would ignite and separation from the Atlas occur when it reached 60% thrust level. The late VECO caused the engine to be at 100% thrust when staging occurred. This caused higher than nominal pressure in the interstage section. As soon as the separation signal was received, the AJ10 engine began to experience thrust decay and pitch control was lost due to an apparent broken wire in the potentiometer. Oxidizer began to leak due to possible damage to the thrust chamber. The combination of the oxidizer leak and loss of pitch control caused vehicle tumbling. Thrust was at essentially zero by 352 seconds. The manual fuel cutoff command was received from the ground at 379 seconds and the solid third stage ignited at 382 seconds and completed its 40 second burn as planned. However, the third stage and probe were now pointed downward and back towards Earth. Final loss of signal and telemetry occurred at 14 minutes.

The Atlas's non-response to the VECO discrete was believed due to a short in the engine relay box but the precise cause of the propulsion system failure in the Able was not determined. The oxidizer leak would have caused the thrust decay, but it was unclear why the gimbaling failed or an oxidizer leak developed and the unintended 100% thrust at separation was not thought to be in of itself enough to damage the vehicle.

Complete flight report can be found on the STL archives on sdfo.org

[WallE]

Atlas 105D/Agena 1202 ("Big Town") launched from PALC 1-2 on October 21, 1961, carrying the fourth MIDAS satellite and the last "open" mission before the early warning and intelligence-gathering satellite programs were made top secret. The flight was normal throughout booster phase and part of sustainer phase; at T+186 seconds the Atlas lost roll control. The booster rolled about 8-1/2 times before staging. As pitch and yaw stability were maintained, the booster was able to complete its burn on time and place the Agena and satellite vehicle on the proper flight trajectory, but the latter ended up using a significant amount of attitude control gas correcting the roll imparted into it by the Atlas. Once in orbit, a malfunction of the Agena horizon sensor combined with the control gas depletion caused an uncontrolled rotation in the pitch plane.

MIDAS 4 successfully detected the launch of a Titan I from Cape Canaveral on October 24; shortly afterwards, one solar panel failed. The satellite vehicle's batteries ran down and the mission was ended in a week. The horizon sensor on the Agena was modified afterward. The Atlas roll control issue was concluded to be the result of one of the booster retrorocket heat shields falling off and exposing transistors in the gyro package to aerodynamic heating, causing their failure. After a repeat of this failure on SAMOS 4 a month later, except in that case the satellite vehicle didn't even make it to orbit, the heat shields were redesigned and the transistors replaced with a different type less prone to thermal runaway.

"Agena Flight History as of 31 December 1967" describes the roll control issue as being largely responsible for the mission failure as it caused the expenditure of most of the Agena's control gas in order to correct it despite GD/A docs claiming it had no effect on anything.

[WallE]

Atlas 70D is raised on PALC 1-2 on August 26, 1960 in preparation for SAMOS 2. The booster launched January 31, 1961, a chilly, gray, overcast winter day and it was out of visibility within 40 seconds. Atlas and Agena performance were normal and the electroscan photo system was tried out, but all T/M was abruptly lost on orbit 21 during an attempted antenna deployment, apparently the antenna separation mechanism caused major damage to or the total disintegration of the satellite. The dead satellite vehicle remained in orbit for 12 years before decaying. The fuzzy images returned from SAMOS 2 were of little value except as a tech demo.

This was also the final launch of the original non-restartable Agena A, which required a direct ascent trajectory to polar orbit. The improved Agena B, which would allow placing the payload in a LEO parking orbit first, had begun flying on Thor vehicles the previous October.

The electroscan system was tried out again on the 7th through 11th SAMOS satellites after a reversion to a conventional film capsule system on 4-6 but the poor quality images were of little use for reconnaissance and the program was abandoned at the end of 1962 by which point CORONA was performing with a high degree of reliability and returning valuable image data.

[WallE]

Atlas 45D/Agena 1007 launched the second MIDAS satellite from Pad 14 at Cape Canaveral on May 24, 1960. As the first MIDAS attempt three months ago had been lost due to an apparent malfunction of the Agena ISDS, it was removed from Vehicle 1007 while being redesigned. Operational MIDAS satellites would be polar orbiting but this was merely a test model to verify the system's functionality and polar orbit was not possible from the Cape so it was launched into a 33 deg orbit.

This was the second East Coast Atlas launch since the twin 51D/48D disasters and special measures were undertaken such as restoring the turbine exhaust ducts to the pads, going back to a wet engine start, having an extended hold down time between engine start and launcher release, and putting extra cameras around the pad, including on the launcher heads (some photos of MIDAS 2's launch show this more clearly than others).

The Atlas and Agena performed well throughout powered flight. In orbit, the satellite vehicle became unstable due to propellant venting which the Agena's attitude control system was unable to compensate for. The infrared sensor returned some data until a probable multicoupler malfunction resulted in completely garbled T/M after orbit 4. Part of the mission plans included detecting a Titan I launch as well as detecting flares on the ground; they could not be carried out due to the T/M failure. What had been a planned 40 month mission, to conclude in September 1963, ended in a mere two days. MIDAS 2 remained in orbit until reentering in 1974.

The operational MIDAS program, to use Agena B, would be moved to VAFB and Pad 14 was turned completely over to NASA and Project Mercury after this launch.

[WallE]

It's apparent from this that there was little improvement a decade after NASA lodged numerous complaints about the quality control of Atlases during the Ranger/Mariner 2 days. Launch vehicles were still requiring extensive modification and repair work at factory acceptance testing and after delivery to Cape Canaveral before they could be deemed flight-ready, and a few times like with Mariner 8 a hardware fault still eluded ground testing and caused loss of the mission.

[Big RI Joe]

I hope this might be of interest

[Big RI Joe]

I have to ask: regarding all these premature cutoff issues: If the flight did not end up going the full range to its intended hostile target would the warhead still explode?

[Proponent]

I would think not. Especially given 1950s reliability, there must be a very reliable way of ensuring that an ICBM launched from Arizona toward Moscow did not blow up Fargo, North Dakota.

[WallE]

I would think not. Especially given 1950s reliability, there must be a very reliable way of ensuring that an ICBM launched from Arizona toward Moscow did not blow up Fargo, North Dakota.

ICBM reliability was only expected to be about 75%. As we have mentioned, quality control on Atlas vehicles always seems to have been pretty bad outside man-rated Mercury boosters where rigid quality standards were enforced. The SLV versions did undergo preflight checks but Atlas missiles were always the low man on the totem pole.

Titan was not any better, the Martin-Marietta plant in Denver was well known to have abominable workmanship and production of Titan II GLVs was moved to a different facility in Maryland to ensure maximum quality control. To be fair Titan SLVs were mostly extremely dependable until the Shuttle caused the planned phase-out of them and quality control collapsed.

And no, nuclear warheads have arming mechanisms on them, actually getting them to detonate/perform fission of the radioactive material is not that easy. If one fell off an exploding missile it's not going to just go off. At most you'd have a conventional explosion like Bluegill Prime when the RSO blew up the warhead on the pad and it just sprayed plutonium everywhere.

[Big RI Joe]

But what about an Atlas ICBM whose sustainer shut down early? The warhead would survive reentry, but would it detonate far short of its intended target?

[Jim]

ICBM reliability was only expected to be about 75%. As we have mentioned, quality control on Atlas vehicles always seems to have been pretty bad outside man-rated Mercury boosters where rigid quality standards were enforced. The SLV versions did undergo preflight checks but Atlas missiles were always the low man on the totem pole.

Titan was not any better, the Martin-Marietta plant in Denver was well known to have abominable workmanship

that isn't true.
a.  Weapon system reliability was 75%.  Not just ICBMs.
b.  Quality control wasn't as bad as you state for either.