Author Topic: Atlas Chronology  (Read 4979 times)

Offline Spaceman Spiff

  • Member
  • Posts: 5
  • Belgium
    • Atlas Rocket Chronology
  • Liked: 7
  • Likes Given: 0
Atlas Chronology
« on: 10/31/2018 06:30 am »
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 -
- Michel -

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #1 on: 10/31/2018 03:14 pm »
Here, I'll help fill out the remainder of 1961.

May: Three missile tests, no orbital Atlas launches this month. All flights successful.

June: Atlas 27E blew up on OSTF-1 at VAFB and badly damaged the facility, it was not used again for 10 months. This was the third and last Atlas lost to booster engine rough combustion at launch, afterwards copper baffles were phased into all Atlas booster engines. Two weeks later, Atlas 17E tumbled out of control and broke up 1-1/2 minutes into launch due to the pitch gyro motor running at half speed. No orbital launches this month.

July: Two successful missile tests. One orbital launch (Midas 3). On Midas 3's launch, the Atlas's programmer reset at staging due to an electrical problem, but no apparent ill effect resulted from this. The Mercury team looked into it anyway just in case.

August: Three launches. Two successful missile tests including the first Atlas F launch. Third was Ranger 1, which failed (but not due to any fault of the Atlas).

September: Three launches. The first was Atlas 26E, which lost sustainer thrust at staging. Immediate cause of the failure was unknown, later traced to spent propellant igniting at booster jettison and damaging plumbing. A few hours after 26E launched, Samos 3's Atlas-Agena blew up on the pad at Vandenberg when an umbilical disconnected too late, causing total loss of electrical power to the launch vehicle. Damage to facilities was not too bad and repair work was completed in just over a month. Third launch of the month was Mercury-Atlas 4 which verified the modifications made after MA-3.

October: Three launches, two successful ICBM tests and one space launch, Midas 4, which made it to orbit despite an Atlas roll control failure (but the mission largely failed due to the resultant incorrect orbit).

November: Six launches, four ICBM tests and two orbital. Atlas 32E was intended to carry a monkey on a suborbital lob, instead it ended up lobbing its passenger into the drink when the sustainer engine shut down at liftoff, after which a thrust section fire caused total loss of control and RSO destruction. An incorrectly installed regulator caused loss of LOX flow to the sustainer gas generator. Then Ranger 2 repeated the same Agena control problem that doomed its predecessor. Samos 4 (notably the first DoD launch to be completely classified and top secret) was lost due to a failure of the Atlas pitch control that put it in an incorrect flight vector that made orbital insertion impossible. Loss of the rate gyro head shield during flight was determined to be the culprit on this and Midas 4. Mercury-Atlas 5 successfully carried Enos the chimpanzee aloft, after which Atlas was considered to man-rated.

December: Six launches. Three were fully successful, one was a partial success, and Atlas 6F suffered a leak in the sustainer hydraulic system at staging, leading to premature shutdown. This flight was also carrying a monkey, although his capsule separated from the Atlas successfully, he was lost at sea when recovery crews were unable to locate it. The only orbital flight this month was Samos 5, which was put into an incorrect orbit due to a late Atlas sustainer cutoff. The film capsule was believed to have reentered and impacted in northwestern Canada but it was never found.
« Last Edit: 11/20/2018 05:16 am by WallE »

Offline Spaceman Spiff

  • Member
  • Posts: 5
  • Belgium
    • Atlas Rocket Chronology
  • Liked: 7
  • Likes Given: 0
Re: Atlas Chronology
« Reply #2 on: 10/31/2018 06:00 pm »
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.

- Michel -

Offline Spaceman Spiff

  • Member
  • Posts: 5
  • Belgium
    • Atlas Rocket Chronology
  • Liked: 7
  • Likes Given: 0
Re: Atlas Chronology
« Reply #3 on: 11/02/2018 09:11 pm »
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.
- Michel -

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #4 on: 11/02/2018 10:10 pm »
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.

They also went back to using a wet start with the booster engines (that is, having the engine tubes filled with inert fluid as a shock damper). The specific reason for the rough combustion was not determined.

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.

I read the postflight report for 48D and it gives a fairly detailed description of the events during the attempted launch. It was not as severe of a fire as what happened on 9C and was more erratic. An explosion erupted out the B-2 side of the missile, followed by automatic engine cutoff commands being issued due to turbopump overspeed. Fire burned for about 30 seconds before slowing down. Around 45 seconds, the fire started up again and continued until final missile explosion at 60 seconds. The fire on 9C was very hot and intense because it was fed by a ruptured LOX line, but on 48D it appears to have been mostly fuel rich.

9C also produced an incredibly powerful explosion that leveled the entire service tower on LC-12 because the propellant valves closed at engine cutoff and the pneumatic system opened the LOX boil-off valve to prevent tank overpressure. It kept venting pressure gas until the tank lost structural integrity and the intermediate bulkhead collapsed, causing the LOX to fall into the RP-1 tank and mix.

As I mentioned, 51D also suffered an airframe failure as a result of the thrust section explosion. It most likely ruptured helium bottles or plumbing in the pneumatic system, with the loss of support pressure, the whole thing crumpled up like a giant soda can and all the propellants mixed. Kaboom. On 48D however it seems that the final explosion started in the fuel tank and there was very little propellant mixing.

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.

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 37441
  • Cape Canaveral Spaceport
  • Liked: 21451
  • Likes Given: 428
Re: Atlas Chronology
« Reply #5 on: 11/02/2018 10:29 pm »

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

Umbilical tower.  The Service tower was unaffected.

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #6 on: 11/03/2018 12:51 pm »
If I remember correctly the service tower sustained some minor damage from flying debris. The pad itself was a scene of total devastation--the concrete launch stand was caved in, the small whip umbilical towers leveled, and the top portion of the main umbilical tower, a one ton piece, was hurtled a couple hundred feet. Kerolox gel is powerful stuff. It took eight months to restore LC-12. They didn't bother rebuilding the large umbilical tower and replaced it with only a small one. The pad hosted a couple of D-series test flights and the second and third Atlas-Ables before being converted for the Atlas-Agena in early 1961.

Offline Spaceman Spiff

  • Member
  • Posts: 5
  • Belgium
    • Atlas Rocket Chronology
  • Liked: 7
  • Likes Given: 0
Re: Atlas Chronology
« Reply #7 on: 11/03/2018 05:30 pm »
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.
- Michel -

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #8 on: 11/04/2018 09:25 am »
Postflight reports that are online include 48D, 60D, 66D, 50D, 9C (the accident investigation report since that wasn't actually a launch), 93D, 13E, 26E, 32E, and 11F as well as a number of later NASA Atlas-Agena and Centaur launches. They're also all East Coast launches, I've never seen any reports for West Coast Atlas launches.

Except for 48D, they're all the "preliminary" reports which were issued three weeks after a launch and contain the basic rundown of events and flight data during the launch as well as a list of all Atlas East Coast launches to date. The full GD/A postflight evaluation reports were issued about a month after the launch. The 48D report has photos and graphs/charts of missile system performance data that aren't in the preliminary reports, and it doesn't have the list of Atlas launches to date.

And of course the reports for Atlas-Centaur AC-3, 4, and 6 are online but not 5 which is the one we really want.  ::)

Also the Wikipedia page on the Atlas D has an incorrect description of what dry/wet engine starts were. I've tried to fix it but some guy keeps reverting the page every time. I hate Wikipedia, I really do.

« Last Edit: 11/04/2018 03:03 pm by WallE »

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #9 on: 11/08/2018 06:02 pm »
Mercury-Atlas 1 of course was the unsuccessful first attempt at launching a Mercury capsule (not counting Big Joe as that was a boilerplate capsule). Hidden behind dense clouds on a rain-soaked Friday morning, the Atlas suffered an apparent structural failure. The capsule transmitted data until impact in the ocean about 6 miles downrange. About 70% of it was recovered along with the Atlas booster engines and a section of plumbing for the LOX boil-off valve.

Aside from the weather preventing any visual coverage of the flight failure, telemetry data was also inadequate. Atlas 50D had only a single telemetry package with 50 measurements being taken in contrast to R&D Atlas missiles which had three telemetry packages. Telemetry indicated an entirely normal, uneventful launch until 57 seconds when a shock was registered in the forward portion of the missile followed by loss of measurements in that area. Fuel tank pressure went to zero followed by an erratic decay in LOX tank pressure. The ASIS system immediately responded by issuing a shutoff command to the propulsion system and a further shock was registered before complete loss of telemetry at 60 seconds. The abort was issued too early in the launch for the Mercury's parachute system to activate so it just pinwheeled its way down into the ocean.

The piece of LOX plumbing recovered from the Atlas had fatigue cracks in it and it was speculated that the forward portion of the LOX tank or the Mercury adapter had experienced aerodynamic bending while approaching the point of Max Q around the one minute mark that resulted in rupture of the Atlas tank section. Telemetry from the Atlas suggested a steady flight path until final loss of data, but this was questionable due to loss of measurements following the initial disturbance. The capsule's rate gyro measurements indicated that the stack may have pitched as much as 10 degrees.

A major redesign effort was undertaken for the rest of 1960 and involved equipping Mercury-Atlas vehicles with thicker tank skin. Also the lack of a launch escape system on MA-1 was suspected to have negatively affected the booster's aerodynamic profile. Future launches would have at least a dummy LES, the flight path was changed to be somewhat shallower to reduce loads, and clear skies were made a requirement to launch so there would be adequate camera coverage. Also after the last Atlas-Able experienced a similar failure caused by bending modes, GD/A began requiring all Atlas upper stage/payload combinations to be given proper structural dynamics testing.
« Last Edit: 11/08/2018 08:18 pm by WallE »

Offline RIB

  • Member
  • Posts: 57
  • USA
  • Liked: 8
  • Likes Given: 120
Re: Atlas Chronology
« Reply #10 on: 11/08/2018 07:27 pm »
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.

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #11 on: 11/08/2018 08:16 pm »
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.

Big Joe was a boilerplate capsule, it didn't have all the hardware of a full Mercury including the life support system and it would have weighed quite a bit less. The full capsule weighed around 3000 pounds. GD/A engineers had also opposed the idea of launching without an escape tower as they said it was needed for aerodynamic purposes. 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).

Had MA-1 succeeded, the next flight would have been an orbital MA-2 using Atlas 77D, but the postflight findings led to that vehicle being recalled and it was never flown.

47D through 52D were a pretty unlucky run of Atlases (49D aside).

Offline RIB

  • Member
  • Posts: 57
  • USA
  • Liked: 8
  • Likes Given: 120
Re: Atlas Chronology
« Reply #12 on: 11/08/2018 09:52 pm »
 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.

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #13 on: 11/09/2018 12:02 am »
Some warheads flown on Atlas were quite bulky, yes. The GE Mk2 RV was around the same weight as a Mercury capsule and the Mk4 flown on Atlas E/F was close to 4000 pounds.

What Mercury had and what Atlas warheads didn't was a hollow adapter section that was prone to vibrating under in-flight loads. There was that and the weight of the capsule pressing on the adapter and causing it to buckle. When the point of Max Q was attained, the shaking, vibrating adapter may have introduced loads into the Atlas's forward tank section that were too much for it to handle. If loads on the Atlas became 5% or greater than the internal tank pressure, it would fail under the stress. Owen Maynard also recalled that at that time, the entire situation of the adapter section and mating Mercury to the Atlas was a mess and nobody had really figured it out yet.

So capsule weight+hollow adapter section that vibrates in flight+poor aerodynamics due to no LES+possibly too steep flight trajectory=loading in excess of what the Atlas could handle.

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #14 on: 11/18/2018 03:42 am »
After MA-2 successfully completed a suborbital flight in February 1961 using a thin-skinned Atlas with reinforcing braces in the adapter section, the next step was an orbital test with Atlas 100D and capsule #8. This was the first Mercury-Atlas with thick-gauge tank skin and the transistorized "square" autopilot instead of the electromechanical "round" autopilot. At mid-morning on April 25, MA-3 lifted from LC-14. Initial jubiliation turned to dismay when the 20 second mark was reached and there was no indication that the Atlas had initiated the programmed pitchover maneuver that would take it out over the ocean, instead it was heading straight upward. As anyone who knows about the physics of space launches will tell you, if a rocket keeps going up, it will reach its intended altitude, but as soon as engine cutoff takes place, it will immediately fall right back down again. If MA-3 were allowed to continue, the Mercury would never reach orbit and simply fall back down along with the spent launch vehicle once powered flight finished and have a very good chance of landing on someone or something along the crowded Florida coastline. Nobody could also be certain that an Atlas with a malfunctioning flight control system wouldn't also randomly pitch over and back towards land.

The launch crew waited as long as they possibly could, but the Atlas finally exceeded the allowable safety margins indicated on the RSO's plot board and he sent the destruct command at T+43 seconds. The Mercury LES (being flown live on an Atlas for the first time) activated and pulled the capsule away, it splashed down just off shore and was recovered 20 minutes after liftoff with minor exterior damage. A small consolation to the launch crew was that the LES had performed well.

Examination of telemetry quickly traced the malfunction to the missile programmer, but it was unclear exactly where the failure point occurred. Two months after the launch, the programmer was found along the beach and discovered to have plastic conformal coating on a pin connector which could have caused loss of electrical contact. There was also the possibility of a short or static discharge during ejection of the electrical umbilicals at liftoff that reset the programmer. Modifications were made to the programmer to prevent a recurrence of either failure mode.

GD/A docs interestingly reveal that the programmer flown in 100D was a replacement installed a few days before the launch when the original unit reset itself during testing due to a timer problem, although this may have just been a coincidence.

The Right Stuff includes an excellent video of MA-3 which also seems to suggest that the Atlas's LOX tank was ruptured by the LES activation as you can see a lot of white vapor coming from the forward end of the vehicle just prior to destruct. The video also very clearly shows the three second delay incorporated into the Range Safety destruct system on Mercury vehicles. Essentially, it worked by shutting down the propulsion system and blocking the destruct signal for three seconds. The ASIS would sense the engine shutdown and command an abort, after which the destruct signal was unblocked.
« Last Edit: 11/19/2018 01:07 am by WallE »

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 37441
  • Cape Canaveral Spaceport
  • Liked: 21451
  • Likes Given: 428
Re: Atlas Chronology
« Reply #15 on: 11/19/2018 12:20 am »
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.

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #16 on: 11/19/2018 01:03 am »
Paul Donnelly I think was the Mercury launch director? In that case, the blame was on him for launching in bad weather conditions and it was not like with Apollo 12 where they had no choice due to an extremely narrow launch window.

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.

Flickr had some photos of the recovered Atlas 50D booster engines and LOX plumbing and there was also a photo of the recovered 100D thrust section, but they don't seem to be on there now (Flickr is weird like that, images seem to appear and disappear). I've always been curious as to where exactly the debris from 100D landed. It was still directly above the pad at destruct, but I never heard anything about the engines or other major components landing on or near LC-14 (as funny as it might be to imagine them falling out of the sky onto the pad like a cartoon anvil). Perhaps the debris spread out more due to the altitude? Certainly the two months it took before anyone stumbled across the programmer would suggest that.
« Last Edit: 11/19/2018 03:58 am by WallE »

Offline Jim

  • Night Gator
  • Senior Member
  • *****
  • Posts: 37441
  • Cape Canaveral Spaceport
  • Liked: 21451
  • Likes Given: 428
Re: Atlas Chronology
« Reply #17 on: 11/20/2018 04:05 pm »

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

Offline WallE

  • Full Member
  • ****
  • Posts: 413
  • Liked: 158
  • Likes Given: 1
Re: Atlas Chronology
« Reply #18 on: 11/20/2018 10:05 pm »
The Delta Intelsat failure from 1968? That didn't go straight up, it started wobbling in the pitch plane soon after liftoff and eventually tumbled out of control, the Range Safety destruct command was set at 108 seconds. IIRC the autopilot had an open circuit that caused loss of pitch control.

Youtube has a video "Counter Catastrophe: The Range Safety Story" that shows this launch.
« Last Edit: 11/21/2018 06:17 am by WallE »

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1