Author Topic: Mariner IV  (Read 9291 times)

Offline Jim

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Re: Mariner IV
« Reply #20 on: 09/22/2022 08:45 pm »

1.  Bit of a disadvantage there compared with the Soviet program which could reuse R-7 pads in just two days.

LV reliability was improving by 1964 but still potentially an issue and the standardized Atlas SLV core had not been adopted across the board yet; Mariner 3 and 4 were still using custom-built Atlas D vehicles tailored for the particular mission needs.

LC-13 was used for Vela in 1963-65 with the sole exception of Mariner 3 while LC-12 was used for NASA missions--Ranger, OGO, and Mariner as well as the FIRE Apollo heat shield tests but each of these required the pad to be reconfigured (also note that 15 months passed between Ranger 5 and 6 so LC-12 didn't get used at all during 1963). Plus of course Ranger used Agena B while Mariner used Agena D which necessitated further modifications.

1.  Not at all a disadvantage since there were three Atlas Agena pads.  R-7 didn't have as many pads

2.  Not really, spacecraft reliability was more of a concern

3.  Pads did not have to be modified between Agena B and Agena D missions

Offline WallE

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Re: Mariner IV
« Reply #21 on: 09/23/2022 01:35 am »
The drewexmachina link seemed to suggest there were differences between Agena B and D launches but they could be wrong. As for spacecraft reliability, it was the biggest concern but LV gremlins did still pop up from time to time, even though CCAS had a better record with Atlas-Agena than Vandenberg. After all, two GATVs were lost to booster malfunctions and this was after the standardized Atlas SLV was flying.

Also there were not three Atlas-Agena pads at the Cape in 1963-64, there were two (LC-12 and 13). LC-14 was in the process of being converted from Mercury launches to GATV during this time and then it was used exclusively for those until being retired from use at the end of the Gemini program.

Offline Jim

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Re: Mariner IV
« Reply #22 on: 09/23/2022 01:57 pm »

Also there were not three Atlas-Agena pads at the Cape in 1963-64, there were two (LC-12 and 13). LC-14 was in the process of being converted from Mercury launches to GATV during this time and then it was used exclusively for those until being retired from use at the end of the Gemini program.

LC-14 had supported Agena before Mercury.  Most of the infrastructure was still there, the reconversion didn't take much.  It was used exclusively for GATV, but didn't have to.
Still doesn't change the fact that Atlas Agena didn't have to rely on one pad and do a quick turn around and hence didn't have a "disadvantage"
« Last Edit: 09/23/2022 01:59 pm by Jim »

Offline WallE

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Re: Mariner IV
« Reply #23 on: 10/03/2022 04:24 pm »
(report is as of January '62)

I agree they seemed to have a worse record with West Coast Atlas-Agena and that was attributed in here to how VAFB lacked some of CCAS's checkout and diagnostic capabilities that had been set up for the Atlas R&D flights (as for example verifying autopilot functionality prior to launch).

As for the point about LC-14 yeah it had hosted those two MIDAS launches way back in 1960 using the prototype Agena A, and even before that the first Atlas-Able launch which a hypergol upper stage. I suppose the infrastructure for Agena such as the propellant tanks was still there though they'd have had to keep it maintained for over four years of non-use--the equipment would rust quickly in the salty coastal air if not kept cleaned and painted (LC-14's umbilical tower rusted fast after the pad's active use ended in 1967 and had to eventually be demolished for safety reasons).

This report also makes the interesting complaint that CCAS had "inadequate" storage facilities for the Agena's propellants.
« Last Edit: 10/03/2022 04:30 pm by WallE »

Offline edkyle99

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Re: Mariner IV
« Reply #24 on: 10/04/2022 07:05 pm »
I agree they seemed to have a worse record with West Coast Atlas-Agena and that was attributed in here to how VAFB lacked some of CCAS's checkout and diagnostic capabilities that had been set up for the Atlas R&D flights (as for example verifying autopilot functionality prior to launch).
By my count, the Cape at no time after the first few months had a better Atlas-Agena launch record than Vandenberg/Point Arguello. 

 Atlas-Agena Flights(Failures)
     with Raw Success Rate

       Running Totals

        Cape         VAFB
------------------------------
1960  2(1)  0.50    1(1)  0.00       
1961  4(3)  0.25    7(5)  0.29
1962  9(5)  0.44   15(6)  0.60
1963 10(5)  0.50   22(7)  0.68
1964 16(6)  0.63   32(8)  0.75
1965 20(7)  0.65   42(9)  0.79
1966 30(8)  0.73   57(10) 0.82
1967 36(9)  0.75   60(10) 0.83
...
1978 48(10) 0.79   61(10) 0.84
------------------------------

Total      109(20) 0.82   

 - Ed Kyle
« Last Edit: 10/04/2022 07:08 pm by edkyle99 »

Offline WallE

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Re: Mariner IV
« Reply #25 on: 10/04/2022 09:09 pm »
By my count, the Cape at no time after the first few months had a better Atlas-Agena launch record than Vandenberg/Point Arguello. 
Broken down more summarily:

10 Atlas failures (4 CCAS, 6 VAFB)
7 Agena failures (4 CCAS, 3 VAFB)
2 failures caused by ground support equipment (2 VAFB)
1 failure caused by the payload shroud (1 CCAS)

To be entirely fair the document I posted was from early 1962 at which point VAFB had more failures (4 including an on-pad explosion) against 3 CCAS failures. Taken in the context of that time CCAS would have been seen as better especially because those 3 failures were due entirely to Agena problems--right after that Ranger 3 failed due to an Atlas guidance system malfunction. Taken as a whole and to the end of the program in 1978 it evens to 10 failures from each launch site.

It should be noted that VAFB had many more failures that occurred in the first two minutes of launch, including a few low altitude explosions. These malfunctions would be fairly preventable with proper prelaunch checks whereas failures like a rocket stage not restarting in orbit are harder to prevent from happening and the evidence does indicate that VAFB did not have as good facilities for prelaunch testing and checkouts of LVs.
« Last Edit: 10/04/2022 10:43 pm by WallE »

Offline Jim

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Re: Mariner IV
« Reply #26 on: 10/05/2022 03:45 am »
By my count, the Cape at no time after the first few months had a better Atlas-Agena launch record than Vandenberg/Point Arguello. 
Broken down more summarily:

10 Atlas failures (4 CCAS, 6 VAFB)
7 Agena failures (4 CCAS, 3 VAFB)
2 failures caused by ground support equipment (2 VAFB)
1 failure caused by the payload shroud (1 CCAS)

To be entirely fair the document I posted was from early 1962 at which point VAFB had more failures (4 including an on-pad explosion) against 3 CCAS failures. Taken in the context of that time CCAS would have been seen as better especially because those 3 failures were due entirely to Agena problems--right after that Ranger 3 failed due to an Atlas guidance system malfunction. Taken as a whole and to the end of the program in 1978 it evens to 10 failures from each launch site.

It should be noted that VAFB had many more failures that occurred in the first two minutes of launch, including a few low altitude explosions. These malfunctions would be fairly preventable with proper prelaunch checks whereas failures like a rocket stage not restarting in orbit are harder to prevent from happening and the evidence does indicate that VAFB did not have as good facilities for prelaunch testing and checkouts of LVs.

It was only CCAS for a short time in the 90's.  It was either CCAFS or CKAFS in this time frame.

It was a known and even studied byt Booz Allen.   The Cape had R&D facilities and Vandenberg used operational facilities. 
Here is a Vandenberg launch console
https://airandspace.si.edu/collection-objects/upper-stage-launch-vehicle-agena-b/nasm_A19650291000
It is like the Atlas ICBM consoles


Offline WallE

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Re: Mariner IV
« Reply #27 on: 10/05/2022 08:26 pm »
Yeah VAFB had an automated countdown sequence designed for operational missile launches--the sequencer logic was modified as a result of Samos 3 to prevent premature umbilical ejection. That particular failure mode probably wouldn't have happened with the Cape's manual countdown sequences.

VAFB launches seemed to have considerable difficulty with the Atlas autopilot since they didn't have the capability of testing them prior to launch. The guidance system on Atlas-Agena was a lemon and it failed routinely on both coasts until being redesigned during 1963. A couple VAFB (both missile and SLV) flights were lost due to the rise-off disconnect falling off and allowing the hydraulics system fluid to escape. At the Cape the mostly they had upper stage issues and the guidance system, which had recently been changed from a vacuum tube to a transistor setup that did not work very well and had to be redesigned. However, it should also be stressed that the guidance system was another component not used during the first two minutes of launch so harder to test on the ground.

And that's not even getting into the endless parade of disastrous Thor-Agena launches from VAFB while CCAFS had a better overall success rate with Thor-based SLVs.

Online catdlr

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Re: Mariner IV
« Reply #28 on: 11/20/2022 09:15 am »
Computers Were So Slow Scientists 'Painted' The First Close Up Image Of Mars



Quote
Nov 19, 2022
Mariner 4 would https://forum.nasaspaceflight.com/Themes/nsf2019/images/bbc/quote.gifbe the first successful deep space spacecraft to fly by another planet and take a close-up image of the surface. The data rates were so low that it would take 8 hours to downlink the 200x200 images to Earth before the computers could start processing the image and printing them out. 
Engineers who had been working on the camera system famously short-circuited the process and began assembling their own image using strips of telemetry printout and coloring them with pastels bought from a local art store.
Tony De La Rosa

Offline Vahe231991

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Re: Mariner IV
« Reply #29 on: 11/21/2022 01:55 am »
It's common knowledge that images taken by the Mariner 4 mission showed the supposed "canals" spotted on Mars by Italian astronomer Giovanni Schiaparelli in 1877 to be non-existent. Were the planners of the Mariner 4 mission aware of suggestions made by some scientists in the early 20th century (e.g. Barnard, Antonialdi, Maunder, Wallace) that the features on Mars that Schiaparelli considered to be canals were not features built by Martian extraterrestrials?

Online Phil Stooke

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Re: Mariner IV
« Reply #30 on: 11/21/2022 02:11 am »
Yes, of course.  Nobody had believed that for a long time. But there were still suspicions that the canals might be real features of some kind such as cracks in the crust caused by impact cratering.  This is from a period when some people thought that lunar crater rays might be cracks in the lunar crust caused by impact craters, possibly brightened by gases escaping through the cracks.  Clyde Tombaugh of Pluto fame drew a map of the region to be imaged by Mariner 4 with a network of canals, and he interpreted small dark spots at canal intersections as impact craters.  The Mariner 4 imaging scientists were looking for possible features like that, not artificial canals.  The attached image is a redrawing of Tombaugh's map.

Tombaugh, C. W., 1965. Provisional Map of Mars, Mariner 4 Region. NASA report CR-64772, TN-701-
66-8. Las Cruces, New Mexico: New Mexico State University, July 1965.
« Last Edit: 11/21/2022 02:25 am by Phil Stooke »

Tags: Mars mariner 4 NASA 
 

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