Rocket launch

Reading about it, there is only 15% more thrust with this rocket compared to the Saturn rocket of the original moon landing missions. I ain't no rocket engineer, but you'd think science and technology would have this some massive factor ahead. But I suppose the materials wouldn't be able hold together. Wild to say the least. Thanks for the pics and sharing. I've always been fascinated with rockets. 10th grade in the library when the shuttle blew apart. M
 
spikedaddy99 said:
Reading about it, there is only 15% more thrust with this rocket compared to the Saturn rocket of the original moon landing missions. I ain't no rocket engineer, but you'd think science and technology would have this some massive factor ahead. But I suppose the materials wouldn't be able hold together. Wild to say the least. Thanks for the pics and sharing. I've always been fascinated with rockets. 10th grade in the library when the shuttle blew apart. M
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It is thrust over weight. Flight systems are significantly lighter these days. Regardless the go-juice is the bulk of the mass.
 
ttmott, Do you have any idea of the BTUs released when burning a gallon of the Oxygen/Hydrogen blend compared to how much we can get out of gasoline?
 
Halfhitch said:
ttmott, Do you have any idea of the BTUs released when burning a gallon of the Oxygen/Hydrogen blend compared to how much we can get out of gasoline?
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Not sure how one would compare BTU's to KNS. But IIRC they still use a modified star core for the APCP boosters. Which more the triples the thrust over a bates core. I would have to dust off the address book and call a friend to get thrust curves and other data.
 
Halfhitch said:
ttmott, Do you have any idea of the BTUs released when burning a gallon of the Oxygen/Hydrogen blend compared to how much we can get out of gasoline?
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In air Hydrogen is about 52,000 BTU's as a heating value per pound. Gasoline is around 19,000 in air. A pound of liquid hydrogen consumes much more volume than a pound of hydrocarbon based fuel. A gallon of liquid hydrogen weighs quite a bit less than a gallon of gasoline. This is ideal sociometry with oxygen approximately at 21 percent however oxygen is oxygen wither a component of air or pure.
However, we use the efficiency of propellants in terms of ISP (specific impulse); measured in seconds. ISP is probably best understood here - https://en.wikipedia.org/wiki/Specific_impulse#:~:text=Specific impulse (usually abbreviated Isp) is a measure,exactly proportional to the effective exhaust gas velocity.
 
JHornsby3 said:
Not sure how one would compare BTU's to KNS. But IIRC they still use a modified star core for the APCP boosters. Which more the triples the thrust over a bates core. I would have to dust off the address book and call a friend to get thrust curves and other data.
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Actually, and I'm not the solid motor expert but rather liquid propellants, the core design is specific to the propellant that is used and the initial thrust needed vs the total burn time. A "star" core exposes more propellant grain for a larger initial thrust but a much faster consumption of the propellant. Designs, and there are many, want to ensure all of the propellant is consumed when the burn gets to the casing. Designs are also concerned with the ejection of unburned propellant - a waste.
 
ttmott said:
In air Hydrogen is about 52,000 BTU's as a heating value per pound. Gasoline is around 19,000 in air. A pound of liquid hydrogen consumes much more volume than a pound of hydrocarbon based fuel. A gallon of liquid hydrogen weighs quite a bit less than a gallon of gasoline. This is ideal sociometry with oxygen approximately at 21 percent however oxygen is oxygen wither a component of air or pure.
However, we use the efficiency of propellants in terms of ISP (specific impulse); measured in seconds. ISP is probably best understood here - https://en.wikipedia.org/wiki/Specific_impulse#:~:text=Specific impulse (usually abbreviated Isp) is a measure,exactly proportional to the effective exhaust gas velocity.
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Thanks ttmott, The beginning of your answer to my question made sense to me and I was impressed with the energy in that rocket fuel but then when reading through that explanation from Wiki, I gotta admit I felt like one does when swimming in heavy breaking surf. Totally overwhelmed and was glad when it was over.;)
 
Halfhitch said:
Thanks ttmott, The beginning of your answer to my question made sense to me and I was impressed with the energy in that rocket fuel but then when reading through that explanation from Wiki, I gotta admit I felt like one does when swimming in heavy breaking surf. Totally overwhelmed and was glad when it was over.;)
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Sorry about that - There was no way I could explain with anymore "clarity" - I'm in the Menucha when it comes to that stuff. It's not cut and dry with respect to simply burning for counting BTU's which is the message.
 
When you explained that gasoline has a heating value of 19,000 compared to the rocket fuel having 52,000, It made me figure out right off that since you have to jump back really quick when you throw a cup of gasoline on a campfire to liven it up, evidently there would be no jumping back if you threw a cup of rocket fuel on your campfire.
 
Halfhitch said:
When you explained that gasoline has a heating value of 19,000 compared to the rocket fuel having 52,000, It made me figure out right off that since you have to jump back really quick when you throw a cup of gasoline on a campfire to liven it up, evidently there would be no jumping back if you threw a cup of rocket fuel on your campfire.
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Yet to throw a cup of kerosene on the fire is different again - but, refined kerosene (known as RP1) or Rocket Propellant No 1 is used in higher ISP propulsion systems. The Atlas V and Dragon both use RP1 and Liquid Oxygen for the booster propellant - they are both bad to the bone boosters. Actually, the Saturn V (Apollo era) first stage was RP1 and LO2.
 
carterchapman said:
Had a good view from Ft. Myers - not a picture quality view though - thanks for posting the great pics.

@dwna1a - doesn't she have 4 shuttle engines?

$100 Billion - wonder what Musk has spent on the reusable Falcon Heavy?
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You are right, I was thinking of the shuttle. She had three main engines. I stand corrected
 
ttmott said:
Actually, and I'm not the solid motor expert but rather liquid propellants, the core design is specific to the propellant that is used and the initial thrust needed vs the total burn time. A "star" core exposes more propellant grain for a larger initial thrust but a much faster consumption of the propellant. Designs, and there are many, want to ensure all of the propellant is consumed when the burn gets to the casing. Designs are also concerned with the ejection of unburned propellant - a waste.
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The formula for the solid propellant is said to be the same formula used by most "Hobby" propellant manufacturers. Aerotech calls it a White Lightening. CTI and others are similar. It has a high aluminum content, thus the white flame. Its a formula that will slow the burn when the chamber pressure gets high. The star core will burn more completely than a Bates core. The star is used for the amount of surface to be burnt being higher and allowing it to come up to pressure faster. A bates will come up to pressure longer and uneven between the two SRB's.

Makes me wonder what two end burners or Moon core grains would do. If a 4" motor can push a 50# rocket to 40k agl at M1.8 and have a burn time of nine plus seconds. How far would a SRB go?

I had a friend that made a high magnesium formula. It lit and had a burn time of .4 seconds. In a Bates grain it would light and if the pad wasn't tied to the ground, would carry the pad with the rocket. He did a star grain in a 38mm L impulse motor. He put that in a minimum diameter rocket that was clocked at mach 3.8 at burnout and flew to 36k agl. The burn time on that one was closer to 0.2. He later redesigned the aerospike nozzle and used that propellant to get a constant burn rate at all altitudes, unlike the tested military design that was only good for horizonal flight. He was asked to work with White Sands when he designed and was successful at a two stage aerospike with a motor inside of a motor. I tried two of his motors in a complex two stage rocket I had. Booster lit and boosted to 7k agl then the sustainer lit with a loud pop. It successfully flew to 13k agl with the motor shoved into the electronics bay 3' up in the rocket. I have photos of it somewhere.
 
370Dancer said:
Doesn't matter right now, but my life has revolved more or less around the space program since Apollo as a kid with relatives in the program, and right up to SLS, and the Human Landing System as work stuff. A few decades ago, I was troubleshooting the Motorola 6800 processors in the Shuttle program, trying to figure out why 2 out of 3 ain't bad, but no launch. We fixed it.
Godspeed to Artemis. I'll stand on my roof, but I think it will be too cloudy to see anything from the West Coast.
Off to captain a survey/sea trial/haul out at 6am. Probably the best 460 I've ever laid eyes and hands on.
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cool were you in Huntsville at any point it time (I've been here 22+ years now )
 
Still am off and on, but mostly on the Army side of the arsenal. Did some stuff at the HOSC. Shuttle, and ISS. Lived there from 2010 to 2012, up at the top of Roberta, where the Rocket Boys built their houses. Now I stay off Hobbs Island road, near Ditto. E Dock was our home base for Beach House back then.
 
370Dancer said:
Still am off and on, but mostly on the Army side of the arsenal. Did some stuff at the HOSC. Shuttle, and ISS. Lived there from 2010 to 2012, up at the top of Roberta, where the Rocket Boys built their houses. Now I stay off Hobbs Island road, near Ditto. E Dock was our home base for Beach House back then.
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awesome I have the largest boat in dry storage at Ditto with the gas prices last summer never got past hobbs island really but hopefully will this summer. I hate that Marcus left for greener pastures but wish him well.
 
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