Author Topic: 6 segment SRB?  (Read 17562 times)

Offline kraisee

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Re: 6 segment SRB?
« Reply #40 on: 08/08/2007 07:30 PM »
Each SRB segment tips the scales right around 150mT when coming back from Utah to KSC ready for flight.

A C-5 "Galaxy" couldn't transport a single SRB segment.

An Antonov-124 could *just* move one at a time.

An Antonov-225 is still only capable of moving one SRB segment at a time.

Train is reasonably economical right now, but any larger would probably require a barge infrastructure of some sorts, and that means Utah would be a bad location.   If you were going to move the ATK plant somewhere else to enable barges, at that point, rather than build another facility and barge everything in, it probably would be more sensible to just relocate the facility to KSC's back yard.

Ross.
"The meek shall inherit the Earth -- the rest of us will go to the stars"
-Robert A. Heinlein

Offline Lee Jay

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Re: 6 segment SRB?
« Reply #41 on: 08/08/2007 07:42 PM »
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Jim - 8/8/2007  1:12 PM

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Lee Jay - 8/8/2007  3:10 PM

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GW_Simulations - 8/8/2007  12:53 PM

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Lee Jay - 7/8/2007  11:43 PM
Bottom line, if you want to move something in the US that's both larger in diameter and heavier than the current SRB segments, you have to do it over water where the limits are, well, insanely large.

Super Guppy?

WAY too heavy.  Antonov 225, maybe.

Still too heavy

That would depend on how much bigger than the current segments.  The thing can supposedly carry 250 metric tons.

Still - totally impractical for the intended purpose.

Offline meiza

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Re: 6 segment SRB?
« Reply #42 on: 08/08/2007 07:45 PM »
As Generic Username said, the moist air in Florida is bad for the segment casting. Aerojet had the facility there, I don't know if they had any problems with that particular thing. The monolithic solids were so huge that they would sag if left lying and had to be held at an angle and rotated continuosly.

Online pippin

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Re: 6 segment SRB?
« Reply #43 on: 08/08/2007 08:01 PM »
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Lee Jay - 8/8/2007  12:43 AM

We recently did a logistics study on moving wind turbine tower sections so I have some data about this.

Rail is indeed limited to 4 meters overall height, which means about 3.7 meters in diameter.

Trucks can go to about 4.8 meters overall height which means around 4.4 meters in diameter.  Hey, send them by truck, you say!

Well...rail is limited to around 160mT, while trucks are limited to around 102mT.  I think the current segments are already too heavy to meet that 102mT requirement for the overall system, so making them bigger would necessitate making them shorter.  That means even more field joints.

There are exceptions to the weight limit, and I think the largest load ever moved over a major US highway was around 600mT (to Utah, an autoclave for a gold mine).  But that's a one-time thing that you can get permits for.  Doing something regularly is entirely different from the point of view of getting permits.

Bottom line, if you want to move something in the US that's both larger in diameter and heavier than the current SRB segments, you have to do it over water where the limits are, well, insanely large.  Did you know there are *several* off-shore cranes that can lift an entire STS stack, with fuel in the ET, and the MLP, quite easily?  Yikes!

Well, well,...
You know, a few years ago we had this startup company here in Germany, called Cargolifter. They wanted to carry 600mT payloads by Blimp. I think what remains of them could be bought quite cheaply... They used to have a H U G E (as in REALLY H U G E) hanger which is now a tropical resort...

Offline Lee Jay

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Re: 6 segment SRB?
« Reply #44 on: 08/08/2007 08:09 PM »
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pippin - 8/8/2007  2:01 PM

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Lee Jay - 8/8/2007  12:43 AM

We recently did a logistics study on moving wind turbine tower sections so I have some data about this.

Rail is indeed limited to 4 meters overall height, which means about 3.7 meters in diameter.

Trucks can go to about 4.8 meters overall height which means around 4.4 meters in diameter.  Hey, send them by truck, you say!

Well...rail is limited to around 160mT, while trucks are limited to around 102mT.  I think the current segments are already too heavy to meet that 102mT requirement for the overall system, so making them bigger would necessitate making them shorter.  That means even more field joints.

There are exceptions to the weight limit, and I think the largest load ever moved over a major US highway was around 600mT (to Utah, an autoclave for a gold mine).  But that's a one-time thing that you can get permits for.  Doing something regularly is entirely different from the point of view of getting permits.

Bottom line, if you want to move something in the US that's both larger in diameter and heavier than the current SRB segments, you have to do it over water where the limits are, well, insanely large.  Did you know there are *several* off-shore cranes that can lift an entire STS stack, with fuel in the ET, and the MLP, quite easily?  Yikes!

Well, well,...
You know, a few years ago we had this startup company here in Germany, called Cargolifter. They wanted to carry 600mT payloads by Blimp. I think what remains of them could be bought quite cheaply... They used to have a H U G E (as in REALLY H U G E) hanger which is now a tropical resort...

Yep...we looked into them in some detail.  There are some issues with that approach but some advantages as well.

Offline henrycheck

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Re: 6 segment SRB?
« Reply #45 on: 08/08/2007 08:09 PM »
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Jim - 8/8/2007  3:12 PM

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henrycheck - 8/8/2007  3:00 PM

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EE Scott - 8/8/2007  2:48 PM

I doubt that ATK would be contracted to build a recreation of an Aerojet design.  Although the way decisions seem to get made currently, one must never say never...


If you wanted to build big solids, why not ATK? Mix the propellant in Utah, ship by train, cast in Florida.

The propellant has to be cast so after it is mixed


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meiza - 8/8/2007  3:45 PM

As Generic Username said, the moist air in Florida is bad for the segment casting. Aerojet had the facility there, I don't know if they had any problems with that particular thing. The monolithic solids were so huge that they would sag if left lying and had to be held at an angle and rotated continuosly.

If we’re going to Mars we’ll need to overcome some hurdles.

At my condominium in Boca Raton I have a wonderful device called an “air conditioner.”

If you were to cluster three of these puppies you’d have a pretty good Ares V.

There are two showstoppers for me:

(1) Vibration - Haven’t seen this discussed but how smooth will the ride be for Orion sitting way up on one elongated SRB?

(2) Acceleration - Can the burn surface be shaped to control the burn rate. Otherwise, acceleration gets pretty nasty near propellant exhaustion.


Online pippin

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Re: 6 segment SRB?
« Reply #46 on: 08/08/2007 08:18 PM »
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Lee Jay - 8/8/2007  10:09 PM

Yep...we looked into them in some detail.  There are some issues with that approach but some advantages as well.

I think the biggest issues were cargo vs. ballast exchange and wind shear. I think they never really solved the latter.

Offline Lee Jay

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Re: 6 segment SRB?
« Reply #47 on: 08/08/2007 08:21 PM »
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pippin - 8/8/2007  2:18 PM

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Lee Jay - 8/8/2007  10:09 PM

Yep...we looked into them in some detail.  There are some issues with that approach but some advantages as well.

I think the biggest issues were cargo vs. ballast exchange and wind shear. I think they never really solved the latter.

Exactly.  The ballast issue invokes silly images in my head.  You have a blimp carrying a 160mT load, and you put the load down.  Next thing you know, you're heading to LEO at Mach 4.   ;)

Offline publiusr

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Re: 6 segment SRB?
« Reply #48 on: 08/10/2007 06:55 PM »
If AJ 260 were around, the upper stage could have been made wider.

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