Of Sea Dragons and other such monsters
Matt Jackson
Truax Engineering site there is nothing more than a couple of drawings and a few
figures, and on Mark Wade's Encyclopeadia Astranautica there is nothing but a
simple line drawing with no textual information.
I also vaguely remember seeing something in a book or magazine about 10 years
ago about a proposed HLLV which was conical in shape (looking rather like a
colossal Apollo capsule) powered by no less than 22 SSME-type engines which
would have been launched and recovered at sea. Has anyone else seen this at all?
Matt Jackson
> I also vaguely remember seeing something in a book or magazine about 10 years
> ago about a proposed HLLV which was conical in shape (looking rather like a
> colossal Apollo capsule) powered by no less than 22 SSME-type engines which
> would have been launched and recovered at sea. Has anyone else seen this at all?
Soon after posting this, I stumbled onto what I think it
was:http://vulcain.fb12.tu-berlin.de/koelle/Neptun/Nep2015.html
lexco...@my-deja.com
You might also be thinking of the Boeing "Big Onion." This was a
mid-late 1970's concept for an SSTO HLLV designed for carrying Solar
Power Satellite payloads into orbit. 2STO versions were also produced.
Aerospace Projects Review will have articles on both the Big Onion and
the Sea Dragon in a few months. The Sea Dragon article will contain
drawings I've never seen anywhere outside of an Aerojet report... very
detailed inboard profiles, separate stage drawings, etc.
Sent via Deja.com http://www.deja.com/
Before you buy.
Maury Markowitz
> I've been trying to look for info about Bob Truax's Sea Dragon, however, on
> the Truax Engineering site there is nothing more than a couple of drawings
> and a few figures
Speaking of, what ever happened to his varioues earlier designs?
> I also vaguely remember seeing something in a book or magazine about 10
> years
> ago about a proposed HLLV which was conical in shape (looking rather like a
> colossal Apollo capsule) powered by no less than 22 SSME-type engines which
> would have been launched and recovered at sea. Has anyone else seen this at
> all?
If it's the one I'm thinking of, it was offered up in the 70's as a
super-heavy SSTO platform, capable of something like 500k to LEO. I saw it
in some silly book on space colonies.
It took off from a drained basin, and landed in the Florida inland waterway
near the Cape, where it was simply towed back for refit. It was to be
constructed cheaply, like a boat as opposed to a spaceship (hmmmm). It also,
IIRC, mounted a full 20 F-1's.
Actually now that I think of it I believe it was a "zero stage" system with
the accent boosters falling off while still well within the atmosphere for
splashdown off the coast.
Maury
Lawson Robinson
The reports with "CASI" and a price after them are available through the NASA
technical report servor CASI. The journal papers should be avaiable from a
university technical library if you have acces to them, or through the AIAA
technical library (www.aiaa.org)
Sea Launch and Recovery of Very Large Rocket Vehicles, J.M. Armstrong and P.L.
Mullins, Aerojet General Corporation, Sacramento, Calif., presented at the IAS
national meeting on large rockets, Sacramento, California, 28 to 31 October
1962. (a lot of detailed information on an earlier version of the concept)
"Sea Dragon concept. Volume 1: Summary," NASA-CR-52817, NAS 1.26:52817,
LRP-297-VOL-1, Aerojet General Corp. Liquid Rocket Plant. (Sacramento, CA), Jan
28, 1963, Contract No.: NAS8-2599/ORDER 6403-SC(STL), 243p, (CASI $47.00 +
$1.50 handling) (detailed report on the final concept)
"Sea Launch Booster System, Feasibility and Cost Study," Volume II,
NASA-CR-50839/LRP-297, VOL. II, Aerojet-General Corp. Liquid Rocket Plant,
Sacramento Calif., Feb. 12, 1963, 521P, NASA contract NAS8-2599, P.O.
6403-SC/STL, (Unclassified report available to U.S. government agencies and
U.S. government contractors only.) (this really is what it says it is, a lot of
program planning and cost projections)
"Sea Dragon concept. Volume 3," NASA-CR-51034, NAS 1.26:51034, LRP-297-VOL-3,
Aerojet General Corp. Liquid Rocket Plant, (Sacramento, CA), Feb 12, 1963,
Contract No.: NAS8-2599/ORDER 6403-SC(STL), 386p, (CASI $62.00 + $1.50
handling) (appendices for the detailed report on the final concept, explaining
specific technical approaches used)
R. C. Truax and J. D. Ryan, "Sea Launch of Rocket Vehicles" (SAE 433A,
presented at the 1961 National Aeronautic and Space Engineering and
Manufacturing Meeting, Los Ange-les, Calif., 13 October 1961), 6-7.
Robert C. Truax, "Sea Dragon in the Manned Mars Mission," The Journal of
Practical Applications in Space, Fall 1990, 8.
R. A. Raffety, "Sea Launch Flight Test Program of a Liquid-Propellant Rocket,"
Aerojet- General Corporation, 20 November 1961, supplement to SAE paper 433A,
presented 13 October 1961, 1.
William H. Ganoe, "Rockets from the Sea," Ad Astra, July/August 1990, 71.
Robert C. Truax, "Thousand Tons to Orbit," Astronautics, January 1963, 45.
(general description of the concept, little technical detail)
Also, the SEALAR program was a US Navy funded effort to develop a much smaller
waterlaunched booster,run by Truax, and unfortunately cancelled in '93 or so.
Lawson Robinson
Lawson Robinson
laws...@aol.com
Derek Lyons
>It was to be constructed cheaply, like a boat as opposed to a spaceship (hmmmm).
A common misconception. Shipbuilding is *not* cheap. And any large
booster is gonna demand QA far in excess of that commonly encountered
in shipbuilding. (Outside of the Naval vessels.) And that alone is
going to drive up cost.
Derek L.
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Jonathan A Goff
> A common misconception. Shipbuilding is *not* cheap. And any large
> booster is gonna demand QA far in excess of that commonly encountered
> in shipbuilding. (Outside of the Naval vessels.) And that alone is
> going to drive up cost.
Shipbuilding is cheap wrt aerospace manufacturing. Quick
comparison. IIRC, the biggest airplanes are less than 1000tons.
The biggest boats are nearly several hundred thousand tons
(once again IIRC). However, despite being almost 500 times
bigger, you never see $100B boats. At least, I haven't seen
any. An airplanes are considered to be cheaper than rockets.
As for QA, it depends a lot on manufacturing practices, design,
simplicity, robustness, tolerances, etc. It is quite possible
with a large vehicle that is very simple (pressure fed engines,
no turbopumps), manufactured with loose tolerances, etc might
actually be easier to build. As it is, the engines they were
planning on using had a parts count two orders of magnitude
lower than average. That alone will really help QA.
Paul Wheeler
run about 100 to 200B.
George Herbert
A few shipbuilding numbers... APL's first set of jumbo containerships
(130 foot beam, couldn't traverse the Panama Canal) would have cost
around $90 million on the open market (they actually paid around $45m
per, due to German government shipbuilding subsidies, but the actual
costs were around/a bit under $100M and would have been if they'd
been made in Finland or South Korea instead). The hull cost was
around 2/3 of the raw cost ($65 million), and hull mass was 15,000
metric tons plus or minus a bit (I am rounding to not disclose
confidential information; my conclusions are accurate to within a
few percent). Price per metric ton was about $4,300, or under $2/lb.
In the late 1980s, the US Navy was procuring AEGIS cruisers for
$300 million or so apiece, with hull costs around $110 million
and hull mass around 4,000 metric tons. That's $27,500 per
metric ton or around $12.50 per pound.
I have fabrication bids from nearby steel fabricators for large
cylindrical steel pressure vessels which might happen to be
intended for aerospace applications with costs ranging from
$2.60 to $5.50 per pound, depending on the bells and whistles
and exact size (all of these were for large sized tanks weighing
tons each (dry mass)).
The low estimate current production run cost for the Space Shuttle
External Tank is around $45 million per; SLWT weighs around 66,000
lbs (30 metric tons) for a cost of $681/lb. This is roughly typical
of current expendable spacecraft structures on a per-pound basis.
-george william herbert
gher...@crl.com
Jonathan A Goff
China is looking at $5B for an aircaft carrier.
Jonathan Goff
"America goes not abroad in search of monsters to destroy. She is the
well wisher to the freedom and independence of all." -- John Q. Adams
Derek Lyons
>The low estimate current production run cost for the Space Shuttle
>External Tank is around $45 million per; SLWT weighs around 66,000
>lbs (30 metric tons) for a cost of $681/lb. This is roughly typical
>of current expendable spacecraft structures on a per-pound basis.
Hmm.... I wonder how the number work out for say, the Roton ATV, a
707, 777, and Airbus....
Derek Lyons
>On Wed, 1 Dec 1999, Derek Lyons wrote:
>
>> A common misconception. Shipbuilding is *not* cheap. And any large
>> booster is gonna demand QA far in excess of that commonly encountered
>> in shipbuilding. (Outside of the Naval vessels.) And that alone is
>> going to drive up cost.
>
>Shipbuilding is cheap wrt aerospace manufacturing. Quick
>comparison. IIRC, the biggest airplanes are less than 1000tons.
>The biggest boats are nearly several hundred thousand tons
>(once again IIRC). However, despite being almost 500 times
>bigger, you never see $100B boats. At least, I haven't seen
>any. An airplanes are considered to be cheaper than rockets.
The difference is because of the complexity of the systems and the
reliability levels of the installed systems. Using the shipbuilding
example; You could build a rather nice (if smallish) container ship
of the same displacement as an 726 (Ohio) class submarine. And the
cost will at least an order of magnitude less. The container ship
uses (in general) things that are produced in far greater quantities
and has a mission that is far more fault tolerant. The *number* of
components in the container ship is several orders of magnitude less.
The systems are simpler, etc... You sea the trend.
A 'big onion' will have far more in common with an Ohio than a
container ship.
>As for QA, it depends a lot on manufacturing practices, design,
>simplicity, robustness, tolerances, etc. It is quite possible
>with a large vehicle that is very simple (pressure fed engines,
>no turbopumps), manufactured with loose tolerances, etc might
>actually be easier to build.
False conclusions from false data sadly. There simply won't *be* any
loose tolerances in a 'Big Onion'. Tolerance slop is deadly. The
costs of the welding and related inspections alone will be
astronomical. (Not to mention the costs of producing and procuring
the parts to be welded.
>As it is, the engines they were
>planning on using had a parts count two orders of magnitude
>lower than average. That alone will really help QA.
It's not just the parts count... It's the stresses that the materials
must withstand, and the care in manufacture and assembly. Simple does
*NOT* mean cheap.
JHare10079
(Derek Lyons) writes:
>Jonathan A Goff <jon...@et.byu.edu> wrote:
>>As for QA, it depends a lot on manufacturing practices, design,
>>simplicity, robustness, tolerances, etc. It is quite possible
>>with a large vehicle that is very simple (pressure fed engines,
>>no turbopumps), manufactured with loose tolerances, etc might
>>actually be easier to build.
>
>False conclusions from false data sadly. There simply won't *be* any
>loose tolerances in a 'Big Onion'. Tolerance slop is deadly. The
>costs of the welding and related inspections alone will be
>astronomical. (Not to mention the costs of producing and procuring
>the parts to be welded.
>
There are many ways of sidestepping the 'astronomical' welding
and inspections cost. Composites is one way. Personal resposibility
is another, notice how often people get careless when everything gets
checked and rechecked. Also, there are many parts that can live with
looser tolerances. Not valves and controls of course, but does a pressure
tank really need to be built with tolerances measured in ten thousandths?
>>As it is, the engines they were
>>planning on using had a parts count two orders of magnitude
>>lower than average. That alone will really help QA.
>
>It's not just the parts count... It's the stresses that the materials
>must withstand, and the care in manufacture and assembly. Simple does
>*NOT* mean cheap.
>
Material stresses are part of design procedure.
Using materials that are easier and cheaper to work with cuts down
on cost. Higher margins lower the critical nature of all those inspections.
Lower parts count can lower costs dramatically. I agree that
simple is not automatically cheap. However, complex is automatically
expensive.
John Hare
Jonathan A Goff
> In article <384e7b35....@hurricane.ispnews.com>, el...@hurricane.net
> (Derek Lyons) writes:
> >False conclusions from false data sadly. There simply won't *be* any
> >loose tolerances in a 'Big Onion'. Tolerance slop is deadly. The
> >costs of the welding and related inspections alone will be
> >astronomical. (Not to mention the costs of producing and procuring
> >the parts to be welded.
> >
> There are many ways of sidestepping the 'astronomical' welding
> and inspections cost. Composites is one way. Personal resposibility
> is another, notice how often people get careless when everything gets
> checked and rechecked. Also, there are many parts that can live with
> looser tolerances. Not valves and controls of course, but does a pressure
> tank really need to be built with tolerances measured in ten thousandths?
Yes, in the long run, lower end composites are likely to
be far cheaper than metal hulls, as welding is labor
intensive, as is the QA. E-beam cured S-glass/epoxy
tanks OTOH are fairly simple, especially if you aren't
using cryogenic fuels. There is more than one way to build
a rocket. Admittedly, Sea Dragon was supposed to be welded
metal. My personal opinion though is that fiberglass is
now mature enough of a technology to be superior when all
costs are considered.
> >It's not just the parts count... It's the stresses that the materials
> >must withstand, and the care in manufacture and assembly. Simple does
> >*NOT* mean cheap.
Pressure fed engines run at lower temperatures, and lower
pressures than turbopump fed engines. TRW was able to
fabricate an engine that was capable of 250klbf for only
$60k (manufacturing costs were only about $12-15k or that).
It's doable, it has been done before.
As it is, the design I'm working on is about as simple as
thiers. It also uses a lower temperature fuel, and has
100% film cooling of the thrust chamber and the nozzle.
Since it is meant to run at 300-500psi, it also has a lower
overall pressure than most rockets (by an order of magnitude).
Also, the pump design (John's design actually) has so few
parts that it actually might have less parts than the pressure
fed engines that Truax was working on.
Simplicity + Large margins + Robust Design + Low Stress
+Low Temperature = Much easier to make.
> Material stresses are part of design procedure.
> Using materials that are easier and cheaper to work with cuts down
> on cost. Higher margins lower the critical nature of all those inspections.
> Lower parts count can lower costs dramatically. I agree that
> simple is not automatically cheap. However, complex is automatically
> expensive.
Pretty much so. Inspection time is proportional to both
size and parts count. By eliminating high inspection items
such as welds, and reducing parts count by ~99% you can
greatly simplify the QA process while still keeping the
reliability high .
Yvan Bozzonetti
Matt Jackson <Mattj...@cableinet.co.uk>
3840683C...@cableinet.co.uk...
> I've been trying to look for info about Bob Truax's Sea Dragon, however,
on the
> Truax Engineering site there is nothing more than a couple of drawings and
a few
but a
> simple line drawing with no textual information.
>
>
launched, two stages liquid booster with presure feed motors; Few, large
motors are used to simplify desing. The SSME bunch is at the opposite side.
Sea Dragon(s) would use H2O2 and jet A, the nearest thing to it (them) is
the Be2 launcher from Beal, indeed a baby dragon.
Yvan Bozzonetti.
Jonathan A Goff
> I think Sea Dragon is a concept with many variants. The basic is a sea
> launched, two stages liquid booster with presure feed motors; Few, large
> motors are used to simplify desing. The SSME bunch is at the opposite side.
> Sea Dragon(s) would use H2O2 and jet A, the nearest thing to it (them) is
> the Be2 launcher from Beal, indeed a baby dragon.
Actually, Sea Dragon planned on using LOX/Kerosene,
because LOX/Kerosene has a specific density of .96,
whereas H2O2/Jet A has a specific density of about
1.3 or more. Anything over specific density of about
1.05 won't float (sea water is a bit more dense than
fresh water).
Jonathan A Goff
> JRS: In article <Pine.GHP.4.21.991209...@leo.et.byu.ed
> u> of Thu, 9 Dec 1999 22:12:11 in news:sci.space.tech, Jonathan A Goff
> Is that a real problem? Just add a zeroth stage, with large tanks but
> no engines, and "drop" it at take-off. Easily recovered; won't need
> avionics. Might conflict with strategy for "abort directly after lift-
> off", though.
Well, the approach I would take if I ever got to that point
would be to use a low density platform underneath the
rocket. A little hole in the middle to let the exhaust not
burn the platform up. It could even be inflated tubes.
Dr John Stockton
u> of Thu, 9 Dec 1999 22:12:11 in news:sci.space.tech, Jonathan A Goff
<jon...@et.byu.edu> wrote:
>On Thu, 9 Dec 1999, Yvan Bozzonetti wrote:
>
>> I think Sea Dragon is a concept with many variants. The basic is a sea
>> launched, two stages liquid booster with presure feed motors; Few, large
>> motors are used to simplify desing. The SSME bunch is at the opposite side.
>> Sea Dragon(s) would use H2O2 and jet A, the nearest thing to it (them) is
>> the Be2 launcher from Beal, indeed a baby dragon.
>
>Actually, Sea Dragon planned on using LOX/Kerosene,
>because LOX/Kerosene has a specific density of .96,
>whereas H2O2/Jet A has a specific density of about
>1.3 or more. Anything over specific density of about
>1.05 won't float (sea water is a bit more dense than
>fresh water).
Is that a real problem? Just add a zeroth stage, with large tanks but
no engines, and "drop" it at take-off. Easily recovered; won't need
avionics. Might conflict with strategy for "abort directly after lift-
off", though.
--
© John Stockton, Surrey, UK. j...@merlyn.demon.co.uk / JR.St...@physics.org ©
Web <URL: http://www.merlyn.demon.co.uk/> - FAQish topics, acronyms, & links.
Correct 4-line sig. separator is as above, a line precisely "-- " (SoRFC1036)
Do not Mail News to me. Before a reply, quote with ">" or "> " (SoRFC1036)
Dr John Stockton
u> of Fri, 10 Dec 1999 21:26:38 in news:sci.space.tech, Jonathan A Goff
>> u> of Thu, 9 Dec 1999 22:12:11 in news:sci.space.tech, Jonathan A Goff
>> <jon...@et.byu.edu> wrote:
>> >Actually, Sea Dragon planned on using LOX/Kerosene,
>> >because LOX/Kerosene has a specific density of .96,
>> >whereas H2O2/Jet A has a specific density of about
>> >1.3 or more. Anything over specific density of about
>> >1.05 won't float (sea water is a bit more dense than
>> >fresh water).
>>
>> Is that a real problem? Just add a zeroth stage, with large tanks but
>> no engines, and "drop" it at take-off. Easily recovered; won't need
>> avionics. Might conflict with strategy for "abort directly after lift-
>> off", though.
>
>would be to use a low density platform underneath the
>rocket. A little hole in the middle to let the exhaust not
>burn the platform up. It could even be inflated tubes.
Same thing.
But I've seen designs (for what?) with well-submerged buoyancy tanks and
struts to hold load above water. This could position itself under a
landed Sea Dragon and lift it; ISTM preferable to have sea level below
the high-tech vehicle, both at checkout and at launch
--
Š John Stockton, Surrey, UK. j...@merlyn.demon.co.uk Turnpike v4.00 MIME. Š
Web <URL: http://www.merlyn.demon.co.uk/> - FAQqish topics, acronyms & links;
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Don't Mail News. Y2k for beginners http://www.merlyn.demon.co.uk/year2000.txt
gbaikie
100...@leo.et.byu.ed
} > u> of Thu, 9 Dec 1999 22:12:11 in news:sci.space.tech, Jonathan A
Goff
} > <jon...@et.byu.edu> wrote:
} > >
} > >> I think Sea Dragon is a concept with many variants. The basic is
a sea
} > >> launched, two stages liquid booster with presure feed motors;
Few, large
} > >> motors are used to simplify desing. The SSME bunch is at the
opposite side.
} > >> Sea Dragon(s) would use H2O2 and jet A, the nearest thing to it
(them) is
} > >> the Be2 launcher from Beal, indeed a baby dragon.
} > >
} > >because LOX/Kerosene has a specific density of .96,
} > >whereas H2O2/Jet A has a specific density of about
} > >1.3 or more. Anything over specific density of about
} > >1.05 won't float (sea water is a bit more dense than
} > >fresh water).
} >
} > Is that a real problem? Just add a zeroth stage, with large tanks
but
} > no engines, and "drop" it at take-off. Easily recovered; won't need
} > avionics. Might conflict with strategy for "abort directly after
lift-
} > off", though.
}
} Well, the approach I would take if I ever got to that point
} would be to use a low density platform underneath the
} rocket. A little hole in the middle to let the exhaust not
} burn the platform up. It could even be inflated tubes.
}
the same diamater. Cap one end. Fill with water, so it's floating like
a deadhead in the water with the end about 5' above water.
Put rocket on top of it. If you don't want rocket in the water
pressurized pipe with air to add floatation. Pipe should be strong
enough to withstand somewhere around 200 psi and be rigid enough.
When ready to blast-off, put some fuel in pipe and lite- this will give
the rocket a boost. Plus, you don't need to worry about rocket exhaust,
since it will be moving (say around 100mph) at the time the rocket is
lit.
Cheap, portable launch pad that gives a launcher a leg up- and no
endangered ducks to worry about.
-gb
Lawson Robinson
is that because of the pressurized interstage and 1st stage engine areas in the
Sea Dragon, and the LH2 2nd stage fuel (and as a baseline, LH2 payload),
swithching from RP-1 to H2O2 as the 1st stage fuel would still give an overall
density less than that of sea water. In fact, the original concept used a
huge ballast weight to keep the vehicle vertical for launch (and as a plug to
avoid separation of the flow due to overexpansion during underwater start up).
If there are problems with bouancy, they would probably be in the towed
configuration on the way to the launch sight. I'm including tables of Sea
Dragon design parameters in the hope that others will play with the concept.
For the density calculations, the overall volume is needed. I'll try to work
that out later. A first order estimate could leave tank volumes as they are.
A better analysis would need some assumptions on mixture ratio and an
adjustment of the tank volumes. Of course to really do it right, a full
re-analysis of the whole system is needed. The data comes from the final
report on the Sea Dragon from Aerojet.
SUMMARY OF SEA DRAGON VEHICLE CHARACTERISTICS - CONFIGURATION No. 135
PROPULSION
Main Stape Enpines
TVC
Item Stage I Stape II
(4) Enpines
Nominal Thrust (lb) 80 x 10^6(sea level) 14.12 x 10^6
(vac) 53,200 (ea)
Operating Time (sec) 81 260
1,340
Nominal Chamber Pressure (psia) 300 75
75
Nozzle Area Ratio 5.O:1 20:1 (expanding
nozzle) 20:1
Oxidizer LO2 LO2
LO2
Weight Oxidizer - Full Tank (lb) 17,617,568 8,005,045
583,000
Fuel RP-1 LH2
LH2
Weight Fuel, Full Tank (lb) 7,659,812 1,601,009 (and
line) 116,OO0 (total)
Mixture Ratio - Oxidizer/Fuel 2.3:1 5:1
4.0:1
Stage Propellant Mass Fraction 0.888 0.887
--
VEHICLE WEIGHT
Vehicle Weight (lb)
Item Recoverable
Expendable
Payload (nominal) 1,100,000*
1,121,O00
Stage I At Launch (full tanks) 28,217,195
27,961,397
Stage I Empty (dry) (2,939,715) (2,684,O17)
Stag II At Launch (full tanks) 10,631,893
10,631,893
Stage II Empty (dry) (1,025,839) (1,025,839)
__________
__________
Nominal Total Takeoff Weight 39,950,000
39,710,0OO
VEHICLE PERFORMANCE
Stage I Stage
II
Velocity Increment (ft/sec) 5,800
17,630**
Maximum Acceleration (g) 4.21 5.2***
Altitude at Burnout (ft) 125,0OO 750,000
(150 nm)
Altitude at Injection
1,822,8OO (299.8 nm)
* This figure includes the beneficial effect of an eastward
launch.
It includes allowance for a payload decrement of 3.16% for
underwater
performance losses and 7.66% for a continuous burn versus
restart trajectory
(total penalty = 10.8%). It should be recognized that the
preliminary staging
ratio selection of 1.92 results in a payload 7% lower than the
optimum value of
1.4. Use of a more optimum staging ratio would result in a
payload of approxi-
mately 1,170,000 lb for the recoverable vehicle.
** The performance given is for the recoverable vehicle. The data
for the
expendable vehicle does not differ significantly.
*** At completion of the high thrust phase.
SEA DRAGON STAGE I RECOVERABLE
CONFIGURATION No. 135 WEIGHT BREAKDOWN
Ex
pendable Subtotal
Propellants Weight (lb) Version
(lb) (lb)
LO2 17,617,568
RP-1 7,650,812
25,277,380
Tankage
RP-1 Tank 420,496
RP-1 Slosh Baffles 33,200
LO2 Tank (Includes Common Blkhd) 948,678
(874,280)*
LO2 Slosh Baffles 40,000
LO2 Tank Insulation 18,000
Insulation, Common Bulkhead 9,479
Encapsulation Skin 13,428
Insulation (Methane RP-1) 1,760
Encapsulation Skin 2,493
(1
,413,136) 1,487,534
Skirts, Lines, and Structure
Forward Skirt and Separation Equipment 29,200
Aft Tank Support Skirt 39,000
Structure between Gimbal and Injector 54,000
Oxidizer Line from Tank to Injector 59,000
Fuel Line from Tank to Chamber 40,900
LO2 Fill and Vent System 500
RP-1 Fill and Vent System 500
Oxidizer Pressurization Equipment 3,1160
(2
12,060) 226,260
Engine System
Gimbal 122,600
Actuators 44,000
Injector Assembly 88,500
Thrust Chamber 180,000
Ballast Mounting Structure 18,400
LO2 Valve 23,400
RP-1 Valve 25,600
Oxidizer Pressurant 236,000
Heat Exchanger 8,200
Fuel Pressurant 178,000
Fuel Pressurization Equipment 700
Fuel Trapped in Tubes 100,000
1,025,400
Miscellaneous
Recovery Flare and Equipment 124,200 (0)
Insulation on LO2 Line 2,104
Insulation on Pressurant Line 840
Misc. Weight (5% Tankage) 73,477
200,621
Structural Strengthening not Required
for Expendable Vehicle
(-43,000) (33,421}
TOTAL SYSTEM WEIGHT
28,217,195
(27,961,397)
Total Propellant Weight 25,277,380
Less Outage 252,774
Total Usable Propellant 25,066,406
Stage Mass Fraction = 25,066,406/28,217,195 = 0.888 (0.896)
* The figures in parenthesis refer to weight changes for an expendable
version of Configuration No.
135.
SEA DRAGON STAGE II
CONFIGURATION No. 135 WEIGHT BREAKDOWN
Propellants Weight (lb)
Subtotal (lb)
LO2
in Tank 7,918,356
in Line to Chamber 86,689
8,005,045
LH2
in Tank 1,601,009
1,601,009
_________
TOTAL
9,606,054
Tankage
LO2 Tank 123,310
LH2 Tank (includes bulkhead) 318,396
Encapsulation skin 13,428
Insulation on Bulkhead 9,479
464,613
Skirts, Lines, and Structure
Aft Tank Skirt 211,984
Skirt Between LO2-LH2 Tank 27,137
LO2 Line to Chamber 4,700
LH2 Line %o Chamber 1,360
Vortex Structure 2,700
LO2 and LH2 Fill and Vent System 1,525
Fuel Pressurizing Equipment 1,820
251,226
Engine System
Injector Assembly 10,000
Thrust Chamber 51,400
Expandable Nozzle 71,500
TVC System (Structure, Engine, Mounts) 5,300
LO2 Valve 3,640
LH2 Valve 4,480
Heat Exchanger 13,400
TVC Pressurization System 14,550
Oxidizer Pressurization Gases 52,000
Fuel Pressurization Gases 18,500
244,770
Miscellaneous
Fuel Tank Insulation 36,000
Oxidizer Tank Insulation 6,000
Misc Weight (5% of Tankage) 23,230
65,230
TOTAL SYSTEM WEIGHT 10,631,893
Total Propellant Weight 9,606,054
Less Outage (1% of Total) 96,060
Less LH2 Cooling Requirements 40,560
Less 1st Stage TVC Weight 42,000
TOTAL USABLE PROPELLANTS 9,427,434
Mass Fraction = 9,427,434/10,631,893 = 0.887
Lawson Robinson
laws...@aol.com