Need Accurate ATK GEM-46 Booster Dimensions

[Ez2cDave]

Back in 2008 or 2009, the R.S. Barker "Silverleaf Design" drawing of the DELTA III was being discussed on another forum group. That drawing incorrectly shows the DELTA III as having GEM-40 boosters.

The creator of that drawing was made aware of the errors and posted an acknowledgment on the other forum, but the dimensions for the GEM-46 Boosters have never been changed on the drawing.

Does anyone have the actual dimensions for the GEM-46 boosters ?

Actual diameter ( I have heard 45.898" & 1170mm /46.06", but that is unconfirmed ) . . . Motor Case Length . . . Nose Cone Length and "shoulder" contour ( "shoulder" is not present on the GEM-40 ). . .

Overall lengths for the 3 different GEM-46 configurations (fixed/ground-ignited / 495.1", vectorable/ground-ignited / 493.9", & fixed/air-ignited /511.2" ).

I am assuming that the variety in overall lengths are due to the different nozzle configurations, with casing dimensions and nose cone details remaining constant.

I have the ATK Space Propulsion Products Catalog, but it is not specific in dimensions . . .

Thanks !

[Ez2cDave]

I have been provided with the dimensions of the GEM-46 case case and a few other details , which is certainly a big help !

I still need the dimensions for the Nose Cone / Frustum for the GEM-46, which a very different from the one used on the GEM-40.

Somebody out there must have this data . . .

Thanks, in advance !

[rocketguy101]

I just found this astronautix article (http://www.astronautix.com/engines/gem46.htm)... now I am curious how far off from the "1.17 m (3.83 ft" your information shows? 1.17 m = 46.06285 inch

[troj]

Here's what I have for Delta III boosters. It took quite a bit of digging to find it; I found this years ago, when we did our big one, so don't ask where I found it -- I'd have to dig out my notes, and I have zero clue where those are. What I do have is my scaling spreadsheet.

Diameter: 46" (Thus GEM-46)
Length: 577.2"
Nose Length: 88"
Nose Tip Radius: 5"
Nozzle Diameter (ground start): 36.96"
Nozzle Diameter (air start): 49.32"
Nozzle Length: 30 2/3"

Them GEM-40s are for the Delta II.

-Kevin

[rocketguy101]

I still need the dimensions for the Nose Cone / Frustum for the GEM-46, which a very different from the one used on the GEM-40.

could you scale that from the drawing in this article (http://www.spacelaunchreport.com/thorh13.html)?

[Ez2cDave]

could you scale that from the drawing in this article (http://www.spacelaunchreport.com/thorh13.html)?

That would be assuming that the drawing was accurate and to scale.

It might be possible from a highly-detailed photo, taken 90 degrees perpendicular to the Nose Cone, but I have not seen anything like that.

[Ez2cDave]

...

[Ez2cDave]

,,,

[Ez2cDave]

Anyone have any info on the Nose Cone dimensions for the GEM-46 ?

[Delta-IV]

Anyone have any info on the Nose Cone dimensions for the GEM-46 ?

I am curious as to why you need such great detailed dimensioned drawings.

Most of the drawings that aerospace companys have are either proprietary or ITAR restricted. If anyone here on these forums had access and provided them they would be liable.


Please contact ATK.

[Ez2cDave]

I am curious as to why you need such great detailed dimensioned drawings.

Most of the drawings that aerospace companies have are either proprietary or ITAR restricted. If anyone here on these forums had access and provided them they would be liable.


Please contact ATK.

"Why" is simple . . . Accuracy in dimensions and surface detailing, mainly for precision scale, but not critical for sport scale where models are not measured directly.

As for "great detailed dimensioned drawings", I don't see asking for basic external dimensions such as overall length, nose tip radius, separation points, and fastener details as being a matter of "national security".

I have many highly detailed photo's, but would like supporting information to be able to accurately size and place those details.

The Delta is not a "weapons system" and I doubt if anything, other than a lot of its payloads, is highly "classified" about it.

I have contacted ATK & ULA, both by e-mail and surface mail. It is virtually impossible to speak with anyone by telephone ( believe me, I have tried ). I was hoping that they had a PAO or an archivist / historian that I could talk to.

After a reasonable length of time, I will file FOIA requests, if I don't receive any action on the correspondence. It is certainly not the first time I have had to do that, but FOIA is such a slow, lengthy process !

I care NOTHING about any internal structures or functions and am only interested in surface details, dimensions, textures, and colors, as is any other modeler looking to build an accurate scale model.

[Ez2cDave]

Like the title says, I've "gone fishing", so to speak via e-mail and surface mail.

Let's see what comes of this inquiry I have sent out to various companies. I believe that someone out there will provide me with the data I am seeking . . .
I have already received a couple of "nibbles". . . Time will tell !

BTW - Is there a GEM-46 on display anywhere ???

http://i1140.photobucket.com/albums/n561/Ez2cDave/GEM-46_NOSECONEDIMENSIONS_UPDATED-5-23-2011.jpg?t=1306206921

http://i1140.photobucket.com/albums/n561/Ez2cDave/Technicans_between_heavy_booster_and_Delta_III_fir st_stage-2.jpg?t=1306207662

[troj]

BTW, I'd be interested in the numbers you collect, if you wouldn't mind sharing them -- I'd love to go back to my original spreadsheet, and validate the numbers.

As you've already learned, finding information on the Delta III is difficult, at best.

-Kevin

[Delta-IV]

BTW - Is there a GEM-46 on display anywhere ???



Yes there are a few: 9 of them at SLC-17B

http://www.spaceflightnow.com/news/n1105/23grail/

But you need special access to see them. :wink:

[Ez2cDave]

Yes there are a few: 9 of them at SLC-17B

http://www.spaceflightnow.com/news/n1105/23grail/

But you need special access to see them. :wink:

Very funny . . .

I do have a "contact" in the Delta program at KSC . . . I have been out of touch with him for a couple of years, but he would definitely have "access" to any Delta data.

I need to hunt up his e-mail address again !

[Ez2cDave]

BTW, I'd be interested in the numbers you collect, if you wouldn't mind sharing them -- I'd love to go back to my original spreadsheet, and validate the numbers.

As you've already learned, finding information on the Delta III is difficult, at best.

-Kevin

I don't have a problem sharing data, as long as the "Men In Black" don't come to haul me off because I find out what size bolts they use to hold on a nose cone or some other asinine government restriction . . .

As for DELTA III data, I currently have about 400mb of data on it .

[Delta-IV]

Very funny . . .

I do have a "contact" in the Delta program at KSC . . . I have been out of touch with him for a couple of years, but he would definitely have "access" to any Delta data.

I need to hunt up his e-mail address again !

Well I work on the Delta Program here at the Cape...I'll see what I can do... ;)

[Ez2cDave]

Well I work on the Delta Program here at the Cape...I'll see what I can do... ;)

That would be most excellent !

Thanks to everyone who is participating in and contributing to this thread !

[bobkrech]

You might want to look at the Delta II Payload Planners Guide. http://www.ulalaunch.com/site/docs/product_cards/guides/DeltaIIPayloadPlannersGuide2007.pdf

The attachment shows several scaled configurations.

Bob

[Ez2cDave]

The main reason that I am resisting simply scaling an "eye-balled" drawing is that I have already located very accurate data for the GEM-46 motor case . . .

Examples of precise dimensions:

Length of GEM-46 Motor Case, excluding Nose Cone & Nozzle - 447.474"

Diameter of GEM-46 Motor Case - 46.120"

I can't "justify" saying using "approximated / scaled" data from an "approximated" source ( an illustration, for example) on a precisely-built model. This would be OK for Sport Scale, but I want to be more exact.

I need to keep digging and hunting . . .

[GuyNoir]

The main reason that I am resisting simply scaling an "eye-balled" drawing is that I have already located very accurate data . .

Can you build to that level of accuracy?

I know I can't.

[Ez2cDave]

Can you build to that level of accuracy?

I know I can't.

No, I can't, but it seems to me like it "cheapens" a scale model, not to have accurate, dimensioned data. I am talking about a Scale model here, not a Sport Scale model.

Of course, one option would be for a modeler to primarily use un-dimensioned data for his/her model. Then, the model would be built and, using the scale factor in "reverse", the drawing would then be scaled, according to the ACTUAL dimensions of the MODEL, as built . . . 100% accuracy every time !

Frankly, I would be surprised if no one has done / tried that yet . . .

The NAR PINK BOOK has this Scale Data requirement:

QUOTE:

50.12.1 Scale Data: 50 points
Points shall be awarded for data that exceeds the minimum requirements; however, data will be judged on quality, not quantity. All data presented should apply to the particular prototype that is being modeled. Minimum allowable data consists of:

* Scale factor
* Overall length
* Significant body diameter(s)
* Nose cone length
* Fin length and width (if applicable to the prototype)
* Length of transition pieces (if applicable)
* Color pattern (documented either in writing or by photographs)
* One clear photograph, halftone, or photo-reproduction
* For at least all required dimensions listed above, both the actual (prototype) dimensions and the scaled (model) dimensions presented in a table or on a drawing


Dimensional data must be from an accurate source, such as magazines, books, the prototype manufacturer's specifications or data sheets, and so on. Dimensions for which explicit data cannot be found may be calculated by proportioning drawings or photos; dimensions obtained in this manner must be so identified in the data. Drawings prepared by the modeler to facilitate judging must be accompanied by substantiating data or drawings. Photographs from any source are acceptable. The photograph requirement may be satisfied by reproductions of pictures from books and other printed material only if the reproduction is equal in clarity to the original. Any entry not accompanied by the minimum allowable data as listed above shall be disqualified. In addition, the modeler should make an effort to include in the table (or drawing) any additional dimensions (both prototype and scaled) that he/she has tried to accurately scale. Points may be deducted if the scale packet contains data not pertinent to the prototype model, or is presented in such a manner as to complicate judging. The entry shall be judged by the data presented in the scale packet.

END QUOTE:

[Ez2cDave]

Any more thoughts or possible data sources out there ?

[Ez2cDave]

I have a few "feelers" out there . . . Looks promising for getting that Nose Cone / Frustum dimension.

Dave

[troj]

BTW, Dave, I may have a lead on someone who could help get the information you're looking for.

I'm currently waiting for a response from an email I just sent.

-Kevin

[Ez2cDave]

BTW, Dave, I may have a lead on someone who could help get the information you're looking for.

I'm currently waiting for a response from an email I just sent.

-Kevin

Kevin,

Is there any update on the e-mail you sent ?

Thanks,

Dave

[troj]

Is there any update on the e-mail you sent ?

None, unfortunately. :(

If that changes, I'll let you know. This guy was a true insider, and would know how to ask for that kind of information.

-Kevin

[troj]

I heard back from my potential source; give me a bit, and I'll see if I can get dimensional data, or a contact who may be able to get that data.

-Kevin

[Ez2cDave]

I heard back from my potential source; give me a bit, and I'll see if I can get dimensional data, or a contact who may be able to get that data.

-Kevin

Kevin,

Thank you, sir . . . Got my fingers crossed !

Dave

[Ez2cDave]

I finally got the data I had been looking for . . . A long time waiting, but well worth it !

Dave F.