RC Rocketry - Ready to Fly to Orbit

On Saturday, January 24, 2015 at 8:05:58 AM UTC+13, Fred J. McCall wrote:
Mookspew to avoid answering a simple question.

Nonsense. You're asking for a list of flying hardware that uses composite cryogenic tanks. I'm saying that list is classified. Now, you admit USAPS exist and are flying and are using composite tanks. Yet, you refuse to admit composite tanks are flying.

Mookie has made the
claim that composite hydrogen tank technology developed during a
program which never successfully built

No I didn't. I said composite tanks were flying in USAPS (unacknowledged special access program) well before X-33 and the fellows at Lockheed knew it.. You are repeating the line we've been given to explain it all away and that there's nothing to see here folks. lol.

Fact is, there were those at Lockheed who wanted to take the open skill sets and produce an advanced space plane for NASA. There were those who worked on USAPS who didn't want that to happen.

Guess who won?

The black hats won. You're pitching for the black hats, that's clear enough. You're not getting many across the plate these days though. People are waking up. When they start demanding answers there's going to be a lot of embarassment. When they start chopping off heads, you'd better have a place to hide fella... lol.

such a tank is in use in
commercial vehicles today.

I said they're in use today. You're attempting to change the goal posts, because even you recognizes that your position that composite cryogenic tanks cannot exist is untenable. However, since USAPS are built by contractors, the USAP vehicles are commercial vehicles in the sense that they're owned by private companies and flown for DOD buyers.

Still, enthusiasts for composites are still bound and determined to see more open commercialization of the technology. As this 2013 Aerospace America article details;

http://www.aerospaceamerica.org/Docu..._AANov2013.pdf

I have called on him to provide the names
of any such vehicles.

Yeah, and jack booted thugs would show up at my door step and eliminate me with extreme prejudice - and you'd tell everyone I died of pneumonia or something.

He's done nothing but wriggle since.

Nonsense. As the Aerospace America article indicates, Boeing uses 5320-IM7 composite in their tank builds a mixture which is used in commercial cryogenic tanks.


I'm calling bull****.

Wow, that's a surprise - NOT! lol.

Mookspew - the spraying of huge volumes of irrelevant bull**** to try
to obscure the original bull****, in the hopes that the sheer volume
will cause the other person to let a Mook have the last word.

Nonsense - now you're just making things up! lol.

William Mook wrote:

On Thursday, January 22, 2015 at 9:43:48 AM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Tuesday, January 20, 2015 at 11:40:14 PM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Tuesday, January 20, 2015 at 12:26:19 AM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Sunday, January 18, 2015 at 11:16:52 PM UTC-5, Fred J. McCall wrote:
William Mook wrote:

Clueless people ranting ...

Clueless person ranting elided



Interesting that Mookie thought it was 'clever' to edit his original
comment below, replacing "$1,000" with "$10,000". I don't know how to
break it to him, but that is STILL far too low.

(The space shuttle costs about $10,000 per pound of payload,


BWAAAHAHAHAHAHAHA! The Space Shuttle never got anywhere near $1,000
per pound of payload! This is the sort of absolute boner (along with
the nutty things) that leaves people laughing at you, Mookie.


A typo!

That's right, I meant to say $10,000 per pound - and that more advanced systems wanted to reduce that to $1,000 per pound - thanks for the pointer.


And that's typical of you.


To admit to a typo when it occurs? lol. Thanks I guess.


Try reading complete thoughts. I know it's hard for you...


Your brain is off by at least an order of
magnitude.

Nonsense.


Yes, that's generally what your mental deficiencies lead to.


Despite being under-funded, the X-33 brought numerous new technologies to light, including

1) lightweight composite fuel tanks (which is used commercially in hydrogen fueled systems today)


Please identify FLYING HARDWARE using such composite tanks.

https://www.youtube.com/watch?v=C5dmJZzAzxE


Already knew about that. It's well behind what you claimed and
doesn't stem from where you said it does.

Former NASA director Ivan Bekey appeared in front of the Subcommittee on Space and Aeronautics, Committee on Science, at the US House of Representatives. His testimony on April 11, 2001, on NASA's FY2001 budget request 'Aero-Space Technology Enterprise,' spoke extensively about composite LH2 tank structures.

His address to US lawmakers stressed that the X-33 had to continue with composite tanks.


And that's what killed it, since every engineer on the program knew
that the composite tank just couldn't be made to work.

'The principal purpose of the X-33 program is to fly all the new technologies that interact with each other together on one vehicle, so that they can be fully tested in an interactive flight environment,' said Bekey during his testimony.

'Even though the thermal protection system and the engine would be tested, the structure and its interaction with the tanks and support for the thermal protection system would not be tested. Since the biggest set of unknowns in this vehicle configuration have to do with the structure-tankage-aeroshell-TPS-airflow interactions, it is my belief that to fly the vehicle with an aluminium tank makes little sense from a technical point of view..'


You mean the flying hardware using composite tanks that are NOT part of unacknowledged programs. Or flying hardware using composite tanks that are part of unacknowledged programs extend further back - but cannot be talked about openly.


Your claim was "used commercially in hydrogen fueled systems today".
I'm calling bull**** based on your wriggling, above.

Composite hydrogen storage containers are in wide use and under extensive development for a wide range of hydrogen fueled vehicles.


Again, please cite the currently flying vehicles using such tanks.
Stop wriggling and either provide the vehicles or admit you're talking
out your ass.

snip remaining Mooklunacy unread

Those with relevant Q-clearances who pointed to flying hardware throughout unacknowledged programmes, would be subject to arrest. So, all they can do is urge open program managers strenuously to follow specific guidelines without getting themselves arrested by pointing to things in the open literature!


You're an ignorant moron.

Nonsense.

The 'Q Clearance' is a Department of ENERGY
clearance that is equivalent to DoD TS.


And now we dive into Mookie's fictional world. It's all bull**** and
he STILL doesn't know enough to even understand what he's going on
about in order to avoid answering the simple question I originally
asked him.

And Mookie should learn to not bloviate on on topics about which he is
abysmally ignorant.


Since Peter Benchley's book "Q Clearance" was published in 1986, the term Q-Clearance has a more general meaning than the one you've chosen to mean.. This is particularly useful when talking about SAP and USAP clearance process since it reveals very little information the projects to those who have need to know someone is cleared, but they don't want to say what it is they're cleare to do. A more technically accurate description of clearance process may be too revealing - so Q-clearance has gained this sort of informal use.


Wrong.


You are quite correct however that in the U.S. you only have 3 types of classification: Confidential, Secret, and Top Secret. That's it. But this doesn't matter, since the true power of the classification system is the famous 'need to know' policy.

Just because you have a Top Secret clearance doesn't mean you can gain access to all the different Top Secret documents of the CIA, Army, Navy, and Air Force.

However, this 3-tiered classification system is not enough to protect some of the more sensitive information. Therefore additional levels of compartmentalization have been created.

The DOE was the first to formalize this 'need to know' process among its contractors. Thus Q clearance started out as a United States Department of Energy (DOE) security clearance and is still the technical meaning of the term today. Q Clearance in this context is more or less equivalent to a United States Department of Defense Top Secret (TS) clearance as you say. However, its use is far wider ranging outside the DOE particularly among non-military personnel.


Wrong.


Much of the DoE information at the Q level requires collateral access to Critical Nuclear Weapon Design Information (CNWDI).

Such information bears the page marking TOP SECRET//CNWDI and the paragraph marking (TS-N). Note that there is also a Department of Energy "Top Secret" clearance, which is, in fact, rather more limited.


Note that that is a 'caveat', not a 'compartment'. So you're wrong
again.


DOE clearances apply for access specifically relating to atomic or nuclear related materials ("Restricted Data" under the Atomic Energy Act of 1954) and thus Q-Clearance, particularly following Peter Benchley's 1986 novel, "Q Clearance" has become a generic term describing generally the process of proving one's need to know in a SAP or USAP particularly among non-military personnel in unacknowledged programs, since the DOE Q-clearance is issued predominantly to non-military personnel. Military personnel have a more formalized process and generally use Q-clearance in a more technically accurate way as a result.

In 1946 U.S. Army Counter Intelligence Corps Major William L. Uanna, in his capacity as the first Chief of the Central Personnel Clearance Office at the newly formed Atomic Energy Commission, named and established the criteria for the Q Clearance.

There are actually two types of Q clearance: Q-sensitive, abbreviated Q(S), and Q-nonsensitive, abbreviated Q(NS). The difference is that both have access to TOP SECRET Formerly Restricted Data (FRD) and National Security Information (NSI), but Q(S) can access TOP SECRET Restricted Data (RD) whereas Q(NS) can only access Restricted Data up to the SECRET level.

That is Q-Clearance is sometimes used to refer to the additional Sensitive Compartmented Information (SCI) clearance, under which information is buried that needs to be restricted to even fewer individuals.

This TS-SCI is generally called Q-Clearance among non-military types after 1986 following Benchley's Book "Q-Clearance".


Only by the massively ignorant. There is no such thing as 'TS-SCI'
and people with compartmentalized access 1) don't talk about it, and
2) have nothing specific in their clearance level to indicate it.


The informal use of the term to describe higher levels of access is particularly useful if one doesn't even wish to discuss the details of that access. Particularly when even the TS-SCI clearance doesn't provide the secrecy needed for some of the most sensitive projects.


No, it isn't, since one never wants to discuss such things.


This is the reason that Special Access Programs (SAP) are created all the time.


Wrong. SCI and SAP are different things.


In this case only a predetermined list of authorized personnel has access to the project and additional security measures can be taken to keep outsiders away from it.

Most SAPs start out as Unacknowledged Special Access Programs (USAP), better known as Black Projects. The F-117A Nighthawk and the B-2 Spirit are examples of projects that started out as Unacknowledged SAPs.

A DOD manual describes a USAP as follows:

"Unacknowledged SAPs require a significantly greater degree of protection than acknowledged SAPs... A SAP with protective controls that ensures the existence of the Program is not acknowledged, affirmed, or made known to any person not authorized for such information. All aspects (e.g., technical, operational, logistical, etc.) are handled in an unacknowledged manner."

Persons involved in a particular USAP are ordered to deny such a program exists. It's not allowed to react with a "no comment", because that way someone immediately suspects something is being hidden and might be motivated to look further into it. Officers not 'accessed' for a USAP, even superior ones, are to be given the same response. The more sensitive the program, the more protection the commanding officer can demand. He could even subject his personnel to lie-detector tests to see whether or not they have been talking about it to anyone. According to a 1997 Senate investigation:

"Additional security requirements to protect these special access programs can range from mere upgrades of the collateral system's requirements (such as rosters specifying who is to have access to the information) to entire facilities being equipped with added physical security measures or elaborate and expensive cover, concealment, deception, and operational security plans."

There are two versions of the Unacknowledged Special Access Programs. The first one is the regular USAP. These regular USAPs are reported in the same way as their acknowledged versions. In closed sessions, the House National Security Committee, the Senate Armed Services Committee, and the defense subcommittees of the House and Senate Appropriations committees can get some basic information about them. The Secretary of Defense, however, can decide to 'waive' particularly sensitive USAPs. These are unofficially referred to as Deep Black Programs. According to the same 1997 Senate investigation as mentioned earlier:

"Among black programs, further distinction is made for "waived" programs, considered to be so sensitive that they are exempt from standard reporting requirements to the Congress. The chairperson, ranking member, and, on occasion, other members and staff of relevant Congressional committees are notified only orally of the existence of these programs."

This leads to the conclusion that only very few people are aware of these waived Unacknowledged Special Access Programs. Congress certainly doesn't get the information it needs to speak out against newly established waived USAPs and I haven't read anywhere that their opinion is actually appreciated. You could also ask yourself if Congress is told the truth about many of the most sensitive Special Access Projects or if their successors are informed about previously activated (waived) USAPs. Even with regular SAPs Congress is ignored at times:

"Last summer, the House Defense Appropriations Committee complained that "the air force acquisition community continues to ignore and violate a wide range of appropriations practices and acquisition rules". One of the alleged infractions was the launch of an SAP without Congressional notification."

What makes Unacknowledged Special Access Projects even more impenetrable is the fact that a lot of these programs are located within private industry. The U.S. government generally doesn't develop a whole lot. If you look at the defense industry, you have companies like Boeing, Lockheed, Northrop, McDonnell Douglas, TRW, Rockwell, Bechtel, SAIC, or Decision-Science Applications (DSA Inc.), who develop certain technologies for the U.S. government.

Look, the SLWT massed 26.5 tonnes and had a gross lift off weight of 760.5 metric tons - whilst carrying 630 tonnes of LOX and 104 tonnes of LH2. Each tank also had 820 kg of ullage. The tank cost $50 million according to NASA sources.

http://www.aerospaceamerica.org/Docu..._AANov2013.pdf

According to this article - the weight savings we can expect with a composite ET is 40% and the cost savings 20% - So a composite ET would likely mass 15.9 tonnes and cost $40 million whilst carrying 735.64 metric tons of LOX/LH2 propellant.

Rocketdyne had a LOX/LH2 aerospike rocket engine in 1961 that produced 1033..1 kN of thrust and an Isp of 421 seconds at altitude. This is known as the J-2.

It was used on LV's SA-201 through 207 and SA-501 to 503.

Sea level versions with reduced expansion ratio proposed for Saturn II first stage use. These were to use upgraded toroidal aerospike versions (J-2T-200K and J-2T-250K). Studies for toroidal upgrades to Saturn upper stages was also undertaken.

Modestly improved J-2S was tested and provides basis for X-33 linear aerospike engine thirty years later.

https://www.youtube.com/watch?v=-0Y0FS8Z1Qk

The Rocketdyne LOX/LH2 toroidal rocket engine had a thrust of 1111.6 kN. This was proposed for later versions of Saturn V. Toroidal aerospike plug nozzle version of J-2 has Isp of 441 sec.

Thrust: 1,111.60 kN (249,898 lbf).
Expansion Ratio: 119:1
Specific impulse: 441 s.
Unfuelled mass: 1007 kg (2,220 lb).
Thrust to weight: 112.5 to 1.
Status: Study 1967.
Height: 1.25 m (4.10 ft).
Diameter: 2.97 m (9.74 ft).

Now, an 8.4 m diameter toroidal engine at the base of this composite tank has 8x the thrust of the J2-2T-250K - to produce 2 million pounds of thrust. 909.1 metric tons of thrust (8.9 mega-Newtons)producing 441 seconds Isp. (4,324 m/sec exhaust speed). The mass is 8 metric tons. This is 1967 level of performance. The X-33 program saw a 45% increase in performance so we can expect 1,318.2 metric tons of thrust at this Isp.

The Inflatable Reentry and Descent Technology (IRDT) demonstrator was launched on Soyuz-Fregat on 8 February 2000. The inflatable shield was designed as a cone with two stages of inflation.

http://www.spaceflight.esa.int/irdt/factsheet.pdf

A similar system built into the nose of a Space Shuttle External Tank sized composite tank would mass 2.9 tonnes.

http://www.astronautix.com/graphics/z/zirdtiss.gif

and slow the ship to subsonic speeds,

And would use a relatively small 30 tonne aerospike engine at the nose for soft landing down range - this engine masses 0.3 tonnes.

This is the simplest version. A more complex version involves the use of ILC dover inflatable wings;

http://www.engr.uky.edu/~fml/papers/05WAC-61.pdf

Which add another 3 tonnes to the flight system, but give the tank the ability to be air-towed back to the launch center by a recovery plane loitering down range.

Composite Tank 15.9 tonnes
Re-entry System: 2.9 tonnes
Boost Engine: 1.0 tonnes
Landing Engine: 0.3 tonnes
Wings: 3.0 tonnes
----------------------------
TOTAL 22.0 tonnes

This is lighter than the original Al-Li tank without the add-ons! Still carrying 734 tonnes of LOX/LH - and attaining 4.34 km/sec exhaust speed.

Now, propellant fraction to attain 9.20 km/sec orbital speed (7.9 km/sec actual speed, 1.3 km/sec air drag and gravity loss) is;

u = 1 - 1/exp(9.2/4.34) = 0.7145

propellant fraction

and we have 734 MT propellant mass - so

TOW = 734/0.7145 = 1027.2

When we solve Calc of Variation problem we'll need something like 1.28 gee at lift off for optimal performance. So, we need 1,314.8 MT at lift off. A shade under what our performance is.

So, subrtracting off our inert weight and propellant weight from our take off weight we obtain our payload;

p = 1027.2 - 22.0 - 734.0 = 271.2 metric tons (598,250 lbs!)

With cross feeding, and using this as a common core booster, we can get even more performance.

This is something that could have been done any time after 1970 had we the sense to do it!

A careful review of capabilities and publications indicate that aerospace vendors since about the 1970s have had the ability to achieve 2% structure fraction with LOX/LH2 propellant combination and have also had the ability to create advanced aerospike engines that seamlessly operate as a rocket at subsonic speeds and as an external combustion ramjet and scramjet at higher speeds.

Such capabilities give rapid response and other important capabilities to a wide range of USAP platforms.

Meanwhile over this period, NASA oversaw the gradual unraveling of US space faring capabilities.

For this reason when engineers at various aerospace firms tried to push composite technology into the open, after decades of seeing our space program slowly erode, they were slammed down.

Something the size of the External Tank, shaped into a lifting body shape, equipped with advanced thermal protection, carries 734 metric tons of LOX/LH2 propellant, and masses less than 22 metric tons inert weight.

The aerospike engine which comprises most of the aft of a disc shaped lifting body operates like a rocket at roll out, and accelerates the vehicle by rocket action to Mach 1, while maintaining a 7 to 1 LD through Mach 3 and falling to LD 3 through Mach 5.

Ve is 4.35 km/sec at SL and rises to 4.51 km/sec at altitude - for the LOX/LH2 rocket. The external combustion ramjet/scramjet, has an effective Ve of 30 km/sec at Mach 1 and that falls to 22 km/sec at Mach 7 on an almost linear scale.

Mach 1 = 0.34 km/sec
Mach 7 = 2.38 km/sec

The lifting body shape helps reduce gravity drag losses to 1/5th typical, reducing delta vee required to get to orbit moving at 7.9 km/sec from 9.2 km/sec to 8.16 km/sec.

Averages over the speed ranges are;

0 to Mach 1 = 0.34 km/sec -- Ve=4.42 km/sec -- u = 0.0740
Mach 1 to Mach 7 = 2.04 km/sec -- Ve=26.0 km/sec -- u = 0.0755
Mach 7 to Mach 23.2 = 5.78 km/sec - Ve=4.51 km/sec -u = 0.7224

This is a total propellant fraction of 0.8719. Now with 734 metric tons of propellant we have a take of weight of;

734 / 0.8719 = 841.84 metric tons.

841.84 - 734.00 - 22.00 = 85.84 metric tons payload!

189,363.04 lbs of useful material on orbit!



On Friday, January 23, 2015 at 3:41:06 PM UTC-5, Fred J. McCall wrote:
William Mook wrote:

On Saturday, January 24, 2015 at 8:05:58 AM UTC+13, Fred J. McCall wrote:
Mookspew to avoid answering a simple question.

Nonsense. You're asking for a list of flying hardware that uses composite cryogenic tanks.


You claimed COMMERCIAL VEHICLES were doing so. Provide their names.

http://www.fuentek.com/technologies/...Tanks-Cryo.php

There are hosts of commercial applications of cryogenic systems made of composite materials.



I'm saying that list is classified.


So your claim that commercial vehicles are flying using such tanks was
bull****. Thank you for admitting that.

No, your interpretation of what I was talking about is bull****.


Now, you admit USAPS exist and are flying and are using composite tanks.


Bull****. Where did I "admit" any such thing?

Hmm.. I really don't keep any closer track of what you say than you keep track of what I say.

Okay, so you are now saying USAPS do not exist and that composite materials have never ever been used in any flight hardware anywhere ever.

Got it.

Of course you're an idiot to believe that. lol.


Yet, you refuse to admit composite tanks are flying.


No,

So, you admit that composite tanks are flying. Where are they flying exactly if its not in USAPs?

I'm merely calling bull**** on your original claim.

You mean on what you claim is my original claim. lol.

You are now
trying to drag the goalposts to cover the stench of the original
bull****,

Nonsense. Here's what's going on. I made some comments about composite cryogenic structures, which have nothing to do with what you're ranting about - and instead of let that conversation go forward in any meaningful way, here we are catering to your childish outbursts and name calling - and talking about what a liar I am and who said what when. lol.

Fact is, we have the capacity to build 2% structure fraction LOX/LH2 tanks today and we've had that capacity since the 1970s.


but that won't work.

Whatever.

OK, you claim there are secret programs flying liquid hydrogen using
composite tanks. Name one.

You're asking me to create a list of Unacknowledged Special Access Programs to win a bar bet on usenet. haha - that ain't happening.

If you can't,

I won't.

you are merely relating
your delusions

Nonsense. Look, you're the one confused. Let's parse this out logically.

(1) Do you believe there are USAPS that use composite cryogenic
tanks flying yes or no?

and insisting that we must believe you because the
proof is 'secret'.

Nonsense. We started down this track when folks said Lockheed said 'trust me' and didn't know what they were doing. That's bull****. Lockheed knew what they were doing and was using a vast array of technologies in a wide range fo commercial applications and very likely has USAPS flying using the technology.

Look at the toolsets Lockheed and others had in this area since the 1950s. Look at the publications. Look at the solid advice that was given to NASA and ignored by management.

Its OBVIOUS that no company is going to spend the kind of money thease aerospace firms spend on composites and on these types of composites without some need. To insist that they're just doing it for no reason is insanity.

Very like so many of your claims. I call bull****.

Like many of your calls, you provide absolutely not knowledgeable analysis. You just spin things into word games and name calling. A propagandist. That's what you are.

Mookie has made the
claim that composite hydrogen tank technology developed during a
program which never successfully built

No I didn't. I said composite tanks were flying in USAPS (unacknowledged special access program) well before X-33 and the fellows at Lockheed knew it. You are repeating the line we've been given to explain it all away and that there's nothing to see here folks. lol.


Liar.

No, I'm responding to comments that Lockheed said 'trust me' and had no knowledge and somehow fooled NASA. That's not what happened.

You can't change your history, Mookie.

I can respond to your attempt to twist meaning.

Everyone read your
original claim.

You're the one making claims and ignoring meaning.

So now you can provide evidence for your CURRENT
claim.

I'm making statements, you're twisting them into claims which you rant about and come to the inevitable conclusion that whatever I say is bull**** lies and worse. lol. Very predictable you are.

If you can't,

Who died and made you god of usenet? lol.

you are merely relating your delusions

You're the one with the delusion that you can rant on and define what is real and what is not. lol.

and
insisting that we must believe you

Because its true.

because the proof is 'secret'.

Nonsense. You can't have it both ways. Its fa fact the USG runs USAPS. They are very serious about the secrecy of those programs.

I believe given the commercial applications of materials used in cryogenic composite tanks programs, and given the scale of the tools and depth of technical knowledge that is acknowledged in this area, its pretty damn clear that Lockheed and others have significant capacity in this area beyond their immediate need, and that this suggests flying composite fuel tanks as early as 1970s and perhaps earlier.

Its also a fact that when engineers tried to push the technology into the open, I think a careful review of what actually happened in the program the X-33 program, shows it drew the negative attention of the intelligence community. MSM has said 'nothing to see here' since that time. Enthusiasts who know the benefits of the technology are still pushing it into the open in a more conventional airframe. Which is how I would have proceeded all along.


Very like so many of your claims. I call bull****.

Yes, you are deluded that you control reality aren't you? lol. Your calls based upon word games that amount to a misreading of what was intended, have no real basis in reality - other than the fantasy world you attempt to construct. lol.


Fact is, there were those at Lockheed who wanted to take the open skill sets and produce an advanced space plane for NASA. There were those who worked on USAPS who didn't want that to happen.

Guess who won?

The black hats won. You're pitching for the black hats, that's clear enough. You're not getting many across the plate these days though. People are waking up. When they start demanding answers there's going to be a lot of embarassment. When they start chopping off heads, you'd better have a place to hide fella... lol.


Mookie relates his paranoid delusions

Nonsense. Paranoia involves feelings of persecution and an inflated sense of self importance. I'm relating what happened to the X-33 program when folks at Lockheed tried to push composite tank technology into th eopen. In response you are the one 'calling bull****' on that and exhibiting inflated feelings of self importance, and when I say you're not that important, you're hte one feeling persecuted by me! lol.

When you accuse me of paranoid delusions you are projecting your own mental state into the world and hating me for the things you hate most in yourself.

Its sad really.


and insists we must believe him
because it's all 'secret'.

You can't read anything I say for meaning and blame me for it! Look, I will say again this time slowly connecting all the dots.

The black budget of the USG is over half of all defense spending. The USG definitely has USAPS that are flying today, and make the SR-71 look primitive. This is a safe bet.

Now, what would these craft be capable of? SSTO-RLV I would wager.

They likely use advanced composite LH2/LOX tanks. At least older versions. They probably used aerospike technology, and even 'stretched' aerospike technology that uses external combustion scramjets that push the aerospike like a pumpkin seed forward by squeezing it between two shock waves.

All these details were reported over the years in AW&ST and other professional journals.

Now, who is building these advanced aircraft? The usual suspects I would wager is a safe bet.

So, if you look at what sorts of tool sets each major aerospace vendor has, and what they reported to NASA to get the work on the X-33, you get a sense that they've got a lot of experience, over a long period of time.

Far more than they need for known programs. Despite the commercial uses they have put this technology to over the years. It doesn't justify the investment.

This suggests very strongly the tools are being used in USAPS.

This is before we get to the specifics of how the X-33 program was managed.

I call bull****.

Of course you do. Of course you do. Feel better now? Of course you do.


such a tank is in use in
commercial vehicles today.

I said they're in use today. You're attempting to change the goal posts, because even you recognizes that your position that composite cryogenic tanks cannot exist is untenable. However, since USAPS are built by contractors, the USAP vehicles are commercial vehicles in the sense that they're owned by private companies and flown for DOD buyers.


You're a liar

No I'm not. You are.

and you're the one wanting to move the goalposts.

Look, many things get said on usenet. Many more meanings are taken from what is said. The only way to have a fruitful discussion with anyone is to show mutual respect, and not call names. Of course that would mean you have to set aside this self-importance you have - telling people what is true and what is not - and if they disagree with you then they're a liar - and if they don't like being called anmes and continue to disagree with you then they're crazy! lol.

Can you see its all a projection of your own mental instability? Of your own insanity? Of course you can. That's why you hate me so much isn't it?

For telling you the honest to god's truth about your mental state.


I call bull****.

Of course you do. But when you go to bed at night, you hate me don't you? And you cry that you can't make me pay for the lies you think I spread about you. Don't you? Don't you! Of course you do.


Still, enthusiasts for composites are still bound and determined to see more open commercialization of the technology. As this 2013 Aerospace America article details;

http://www.aerospaceamerica.org/Docu..._AANov2013.pdf

I have called on him to provide the names
of any such vehicles.

Yeah, and jack booted thugs would show up at my door step and eliminate me with extreme prejudice - and you'd tell everyone I died of pneumonia or something.


Paranoid liar.

Wait a minute, I didn't say it was happening. I didn't say it was happening to me.

I said serious **** would happen if.. This is what is known as a hypothetical. A hypothetical that you choose to read for your own reasons as literal.

So, see how you're the one who's so very full of bull****? So full of bull**** it must hurt your ample gut when you sit at your terminal

I call bull****.

Of course you do. Of course you do! lol.


He's done nothing but wriggle since.

Nonsense. As the Aerospace America article indicates, Boeing uses 5320-IM7 composite in their tank builds a mixture which is used in commercial cryogenic tanks.


I'm calling bull****.

Wow, that's a surprise - NOT! lol.

Mookspew - the spraying of huge volumes of irrelevant bull**** to try
to obscure the original bull****, in the hopes that the sheer volume
will cause the other person to let a Mook have the last word.

Nonsense - now you're just making things up! lol.


You're a lying paranoid loon.

No I'm not. You on the other hand, are projecting all those things you hate most about yourself on to innocent people and hating them. That way you can feel just a little bit better about yourself can't you?

That's why you're such a good propagandist. You can be relied upon to create a toxic environment wherever you post - and destroy every relationship you've ever had.

Sad really.

I call bull****.

Of course you do. Of course you do!

* * * *

On Friday, January 23, 2015 at 3:58:12 PM UTC-5, William Mook wrote:
Look, the SLWT massed 26.5 tonnes and had a gross lift off weight of 760.5 metric tons - whilst carrying 630 tonnes of LOX and 104 tonnes of LH2. Each tank also had 820 kg of ullage. The tank cost $50 million according to NASA sources.

http://www.aerospaceamerica.org/Docu..._AANov2013.pdf

According to this article - the weight savings we can expect with a composite ET is 40% and the cost savings 20% - So a composite ET would likely mass 15.9 tonnes and cost $40 million whilst carrying 735.64 metric tons of LOX/LH2 propellant.

Rocketdyne had a LOX/LH2 aerospike rocket engine in 1961 that produced 1033.1 kN of thrust and an Isp of 421 seconds at altitude. This is known as the J-2.

It was used on LV's SA-201 through 207 and SA-501 to 503.

Sea level versions with reduced expansion ratio proposed for Saturn II first stage use. These were to use upgraded toroidal aerospike versions (J-2T-200K and J-2T-250K). Studies for toroidal upgrades to Saturn upper stages was also undertaken.

Modestly improved J-2S was tested and provides basis for X-33 linear aerospike engine thirty years later.

https://www.youtube.com/watch?v=-0Y0FS8Z1Qk

The Rocketdyne LOX/LH2 toroidal rocket engine had a thrust of 1111.6 kN. This was proposed for later versions of Saturn V. Toroidal aerospike plug nozzle version of J-2 has Isp of 441 sec.

Thrust: 1,111.60 kN (249,898 lbf).
Expansion Ratio: 119:1
Specific impulse: 441 s.
Unfuelled mass: 1007 kg (2,220 lb).
Thrust to weight: 112.5 to 1.
Status: Study 1967.
Height: 1.25 m (4.10 ft).
Diameter: 2.97 m (9.74 ft).

Now, an 8.4 m diameter toroidal engine at the base of this composite tank has 8x the thrust of the J2-2T-250K - to produce 2 million pounds of thrust. 909.1 metric tons of thrust (8.9 mega-Newtons)producing 441 seconds Isp. (4,324 m/sec exhaust speed). The mass is 8 metric tons. This is 1967 level of performance. The X-33 program saw a 45% increase in performance so we can expect 1,318.2 metric tons of thrust at this Isp.

The Inflatable Reentry and Descent Technology (IRDT) demonstrator was launched on Soyuz-Fregat on 8 February 2000. The inflatable shield was designed as a cone with two stages of inflation.

http://www.spaceflight.esa.int/irdt/factsheet.pdf

A similar system built into the nose of a Space Shuttle External Tank sized composite tank would mass 2.9 tonnes.

http://www.astronautix.com/graphics/z/zirdtiss.gif

and slow the ship to subsonic speeds,

And would use a relatively small 30 tonne aerospike engine at the nose for soft landing down range - this engine masses 0.3 tonnes.

This is the simplest version. A more complex version involves the use of ILC dover inflatable wings;

http://www.engr.uky.edu/~fml/papers/05WAC-61.pdf

Which add another 3 tonnes to the flight system, but give the tank the ability to be air-towed back to the launch center by a recovery plane loitering down range.

Composite Tank 15.9 tonnes
Re-entry System: 2.9 tonnes
Boost Engine: 1.0 tonnes
Landing Engine: 0.3 tonnes
Wings: 3.0 tonnes
----------------------------
TOTAL 22.0 tonnes

This is lighter than the original Al-Li tank without the add-ons! Still carrying 734 tonnes of LOX/LH - and attaining 4.34 km/sec exhaust speed.

Now, propellant fraction to attain 9.20 km/sec orbital speed (7.9 km/sec actual speed, 1.3 km/sec air drag and gravity loss) is;

u = 1 - 1/exp(9.2/4.34) = 0.7145

I made a mistake here - this should be 0.87995


propellant fraction

and we have 734 MT propellant mass - so

TOW = 734/0.7145 = 1027.2

So, the TOW is reduced to

TOW = 734/0.87995 = 834.1

When we solve Calc of Variation problem we'll need something like 1.28 gee at lift off for optimal performance. So, we need 1,314.8 MT at lift off. A shade under what our performance is.

This changes the thrust at take off to; 1,067.6 metric tons

So, subtracting off our inert weight and propellant weight from our take off weight we obtain our payload;

p = 1027.2 - 22.0 - 734.0 = 271.2 metric tons (598,250 lbs!)

Which becomes

p = 834.1 - 734.0 - 22.0 = 78.1 metric tons (172,288.6 lbs!)

Still bigger than the Saturn V payload!

With cross feeding, and using this as a common core booster, we can get even more performance.

This is something that could have been done any time after 1970 had we the sense to do it!

Some call this fantasy, yet its all 1970s engineering! The fact the major aerospace companies have extensive capabilities in this area and have developed COMMERCIAL USES for that - suggests USAPs using the technology are flying.

Using this as a starting point for a common core booster,

On Friday, January 23, 2015 at 10:35:20 PM UTC-5, Fred J. McCall wrote:
William Mook wrote:

Look, the SLWT massed 26.5 tonnes and had a gross lift off weight of 760.5 metric tons - whilst carrying 630 tonnes of LOX and 104 tonnes of LH2. Each tank also had 820 kg of ullage. The tank cost $50 million according to NASA sources.

http://www.aerospaceamerica.org/Docu..._AANov2013.pdf


Note there's nothing here about anything that can actually fly. The
closest is a 30% scale pressure test.


According to this article - the weight savings we can expect with a composite ET is 40% and the cost savings 20% - So a composite ET would likely mass 15.9 tonnes and cost $40 million whilst carrying 735.64 metric tons of LOX/LH2 propellant.

Rocketdyne had a LOX/LH2 aerospike rocket engine in 1961 that produced 1033.1 kN of thrust and an Isp of 421 seconds at altitude. This is known as the J-2.

It was used on LV's SA-201 through 207 and SA-501 to 503.


Wrong. The J-2 was a conventional engine. The aerospike engine that
Rocketdyne DID RESEARCH ON was based on the J-2.

Correct. A typo. Remove the errant 'aerospike'. The aerospike was built in 1967 as a test engine.



Sea level versions with reduced expansion ratio proposed for Saturn II first stage use. These were to use upgraded toroidal aerospike versions (J-2T-200K and J-2T-250K). Studies for toroidal upgrades to Saturn upper stages was also undertaken.


You don't seem to understand the point of an aerospike engine.

Projecting again?

Aerospike and plug nozzles increase the efficiency of low altitude operation while aerospike reduces engine weight and size in this way thrust to weight and performance are both improved in the aerospike.

Here's data complied by Tomita in 199

http://www.aerospaceweb.org/design/a...ures/fig14.jpg

You can see the aerospike does well at low expansion ratios, whilst the conventional bell nozzle does not.


snip Mookfantasy

The Linear Aerospike was based on the J2 Toroidal Aerospike

https://www.youtube.com/watch?v=-0Y0FS8Z1Qk

A 40% reduction in the weight of the External Tank reduces structure fraction to 2% overall from 26.5 metric tons to 15.9 metric tons to carry 734 metric tons of LOX LH2, all for $40 million.

http://ntrs.nasa.gov/archive/nasa/ca...0060056194.pdf

A high efficiency nozzle of low mass combined with exceptionally stiff and strong low mass cryogenic tanks provides a SSTO capability along with a very capable common core booster.


--
"Ordinarily he is insane. But he has lucid moments when he is
only stupid."
-- Heinrich Heine

On Friday, January 23, 2015 at 10:46:59 PM UTC-5, William Mook wrote:
On Friday, January 23, 2015 at 3:58:12 PM UTC-5, William Mook wrote:
Look, the SLWT massed 26.5 tonnes and had a gross lift off weight of 760.5 metric tons - whilst carrying 630 tonnes of LOX and 104 tonnes of LH2. Each tank also had 820 kg of ullage. The tank cost $50 million according to NASA sources.

http://www.aerospaceamerica.org/Docu..._AANov2013.pdf

According to this article - the weight savings we can expect with a composite ET is 40% and the cost savings 20% - So a composite ET would likely mass 15.9 tonnes and cost $40 million whilst carrying 735.64 metric tons of LOX/LH2 propellant.

Rocketdyne had a LOX/LH2 aerospike rocket engine in 1961 that produced 1033.1 kN of thrust and an Isp of 421 seconds at altitude. This is known as the J-2.

It was used on LV's SA-201 through 207 and SA-501 to 503.

Sea level versions with reduced expansion ratio proposed for Saturn II first stage use. These were to use upgraded toroidal aerospike versions (J-2T-200K and J-2T-250K). Studies for toroidal upgrades to Saturn upper stages was also undertaken.

Modestly improved J-2S was tested and provides basis for X-33 linear aerospike engine thirty years later.

https://www.youtube.com/watch?v=-0Y0FS8Z1Qk

The Rocketdyne LOX/LH2 toroidal rocket engine had a thrust of 1111.6 kN.. This was proposed for later versions of Saturn V. Toroidal aerospike plug nozzle version of J-2 has Isp of 441 sec.

Thrust: 1,111.60 kN (249,898 lbf).
Expansion Ratio: 119:1
Specific impulse: 441 s.
Unfuelled mass: 1007 kg (2,220 lb).
Thrust to weight: 112.5 to 1.
Status: Study 1967.
Height: 1.25 m (4.10 ft).
Diameter: 2.97 m (9.74 ft).

Now, an 8.4 m diameter toroidal engine at the base of this composite tank has 8x the thrust of the J2-2T-250K - to produce 2 million pounds of thrust. 909.1 metric tons of thrust (8.9 mega-Newtons)producing 441 seconds Isp. (4,324 m/sec exhaust speed). The mass is 8 metric tons. This is 1967 level of performance. The X-33 program saw a 45% increase in performance so we can expect 1,318.2 metric tons of thrust at this Isp.

The Inflatable Reentry and Descent Technology (IRDT) demonstrator was launched on Soyuz-Fregat on 8 February 2000. The inflatable shield was designed as a cone with two stages of inflation.

http://www.spaceflight.esa.int/irdt/factsheet.pdf

A similar system built into the nose of a Space Shuttle External Tank sized composite tank would mass 2.9 tonnes.

http://www.astronautix.com/graphics/z/zirdtiss.gif

and slow the ship to subsonic speeds,

And would use a relatively small 30 tonne aerospike engine at the nose for soft landing down range - this engine masses 0.3 tonnes.

This is the simplest version. A more complex version involves the use of ILC dover inflatable wings;

http://www.engr.uky.edu/~fml/papers/05WAC-61.pdf

Which add another 3 tonnes to the flight system, but give the tank the ability to be air-towed back to the launch center by a recovery plane loitering down range.

Composite Tank 15.9 tonnes
Re-entry System: 2.9 tonnes
Boost Engine: 1.0 tonnes
Landing Engine: 0.3 tonnes
Wings: 3.0 tonnes
----------------------------
TOTAL 22.0 tonnes

This is lighter than the original Al-Li tank without the add-ons! Still carrying 734 tonnes of LOX/LH - and attaining 4.34 km/sec exhaust speed.

Now, propellant fraction to attain 9.20 km/sec orbital speed (7.9 km/sec actual speed, 1.3 km/sec air drag and gravity loss) is;

u = 1 - 1/exp(9.2/4.34) = 0.7145

I made a mistake here - this should be 0.87995


propellant fraction

and we have 734 MT propellant mass - so

TOW = 734/0.7145 = 1027.2

So, the TOW is reduced to

TOW = 734/0.87995 = 834.1

When we solve Calc of Variation problem we'll need something like 1.28 gee at lift off for optimal performance. So, we need 1,314.8 MT at lift off. A shade under what our performance is.

This changes the thrust at take off to; 1,067.6 metric tons

So, subtracting off our inert weight and propellant weight from our take off weight we obtain our payload;

p = 1027.2 - 22.0 - 734.0 = 271.2 metric tons (598,250 lbs!)

Which becomes

p = 834.1 - 734.0 - 22.0 = 78.1 metric tons (172,288.6 lbs!)

Still bigger than the Saturn V payload!

With cross feeding, and using this as a common core booster, we can get even more performance.

This is something that could have been done any time after 1970 had we the sense to do it!

Some call this fantasy, yet its all 1970s engineering! The fact the major aerospace companies have extensive capabilities in this area and have developed COMMERCIAL USES for that - suggests USAPs using the technology are flying.

Using this as a starting point for a common core booster,

A 3 element common core booster with 2 outboard elements is capable of putting 270 metric tons (595,620 lbs) into Low Earth orbit.

2538 Take off Weight
1,468 S1 Propellant
0.578 u1
3.749 V1

1026 S2 Weight
734 S2 Propellant
0.715 u2
5.454 V2

9.202 dV

Now, 164 metric tons of hydrogen, which is basically the LH2 tank from the tank just described, stretched by 50% and with the LOX tank equipped for occupation - as in the case of the Skylab - we have a 22 ton element with 164 metric ton hydrogen tank forming a flight system - and an updated NERVA engine at the tail end of the upper stage;

NERVA has the following characteristics;

DoE nuclear/lh2 rocket engine. 867.4 kN. Developed 1950-74. Isp=825s.

Status: Developed 1950-74.

Unfuelled mass: 11,860 kg (26,140 lb).

Height: 4.24 m (13.91 ft).
Diameter: 10.55 m (34.61 ft).

Thrust: 867.40 kN (194,999 lbf, 88,451 kgf)
Specific impulse: 825 s.
Exhaust Velocity: 8.09 km/sec.

So we have as an upper stage;

164 metric tons - hydrogen
12 metric tons - NERVA engine
22 metric tons - inert weight airframe

198 metric tons - sub total

72 metric tons - payload

270 metric tons - TOTAL

Now, to boost from LEO to the moon and back requires;

2.95 km/sec - LEO to TLI
2.30 km/sec - TLI to LS
2.30 km/sec - LS to TEI

7.55 km/sec - TOTAL

Alright

u = 1 - 1/exp(7.55/8.06) = 0.60673

And 164 metric tons divided by this fraction is 270 kg - leaving 72 kg of useful load.

82.5 metric tons of LH2 is used to propel the ship into a Trans Lunar Trajectory. 187.5 metric tons arrives at the vicinity of the moon. At 1/6 gee 31.3 metric tons of force is sufficient to support the fully laden ship above the moon. The NERVA engine produces 88.5 metric tons of force and is capable of efficiently slowing the stage to zero velocity at zero altitude 46..55 metric tons of LH2. Thus 140.95 metric tons settle on the lunar surface.

Returning the 72 tonnes to Earth requires 35.0 tonnes of LH2 to blast off. Accelerating at 2/3 gee on the 1/6 gee environment of the moon!

At 200 kg per passenger, 360 passengers may be transported to the moon and back in this way. The main nuclear engine is shut down during the return flight, and the cold engine enters

Using aerobraking at Earth, the system lands and the stage lands 'cold'. This reverses the process of launch. The stage takes off cold and is started on orbit, where it boosts the ship into a lunar transfer orbit and is shut down until it lands on the moon. Once on the moon, the reactor is shut down again until needed for launch. After the boost for Earth return, the reactor is shut down for the last time, this flight.

In this way 4,000 passengers per year may visit the moon and return to Earth.

A fleet of five vehicles of this type built in the 1970s transport 10 tons to the moon per week. Using figures from the USN nuclear submarine program, and realizing that with nuclear power from a smaller nuclear reactor on board, a person may be supported on the moon with 1/4 ton per year. So, 520 tons per year support a moon population of 2,000 after a 1 year build up.

More advanced propulsion does more.

Math is also known as analysis. Its an important part of system design. The basic equations for rocketry is the Tsiolkovsky equation;

Vf = Ve * LN(1/(1-u)) and u = 1 - 1/EXP(Vf/Ve)

and the Rindler equation for relativistic rockets;

Vf = c * TANH(LN(1/(1-u)) and u = 1 - 1/EXP(ATANH(Vf/Vc))


These are important. There are other things too, but understand these and you have the basics.

Another important detail is where we are in the cosmos. All people are on the surface of a ball, which energetically is pretty much the same compared to the energy needed. Energy is a function of speed squared and it takes a different speeds to reach different places in space.

Cost of lift, cost of momentum, are key factors.

We proceed by;

(1) suborbital flight,
(2) orbital flight,
(3) cislunar flight,
(4) inner solar system,
(5) outer solar system,
(6) extra solar,

Suborbital flight first occurred 3 Oct 1942. The first orbital flight occurred 4 Oct 1957 a scant 15 years later. The first lunar flyby 2 Jan 1959. First Venus flyby 12 Feb 1961. First Jupiter flyby 3 Mar 1972. First extrasolar spacecraft 5 Sep 1977.

There are other dimensions as well. Size of payload, cost of system, are people on board?

This thread originally began talking about sub-scale spacecraft that are available for sale. Small spacecraft can be built using MEMS and NEMS technology to implement chemical and solar or laser powered ion propulsion and direct laser propulsion.

MEMS and NEMS can also be used with aneutronic fusion in larger scale systems that is quite capable.

MEMS and NEMS self-replicating systems is capable of significant and rapid growth of capabilities.




On Friday, January 23, 2015 at 11:12:52 PM UTC-5, Fred J. McCall wrote:
It's fantasy until someone does actual design work on it and not just
Mookie-Mathing it.

William Mook wrote:

On Friday, January 23, 2015 at 3:58:12 PM UTC-5, William Mook wrote:
Look, the SLWT massed 26.5 tonnes and had a gross lift off weight of 760.5 metric tons - whilst carrying 630 tonnes of LOX and 104 tonnes of LH2. Each tank also had 820 kg of ullage. The tank cost $50 million according to NASA sources.

http://www.aerospaceamerica.org/Docu..._AANov2013.pdf

According to this article - the weight savings we can expect with a composite ET is 40% and the cost savings 20% - So a composite ET would likely mass 15.9 tonnes and cost $40 million whilst carrying 735.64 metric tons of LOX/LH2 propellant.

Rocketdyne had a LOX/LH2 aerospike rocket engine in 1961 that produced 1033.1 kN of thrust and an Isp of 421 seconds at altitude. This is known as the J-2.

It was used on LV's SA-201 through 207 and SA-501 to 503.

Sea level versions with reduced expansion ratio proposed for Saturn II first stage use. These were to use upgraded toroidal aerospike versions (J-2T-200K and J-2T-250K). Studies for toroidal upgrades to Saturn upper stages was also undertaken.

Modestly improved J-2S was tested and provides basis for X-33 linear aerospike engine thirty years later.

https://www.youtube.com/watch?v=-0Y0FS8Z1Qk

The Rocketdyne LOX/LH2 toroidal rocket engine had a thrust of 1111.6 kN. This was proposed for later versions of Saturn V. Toroidal aerospike plug nozzle version of J-2 has Isp of 441 sec.

Thrust: 1,111.60 kN (249,898 lbf).
Expansion Ratio: 119:1
Specific impulse: 441 s.
Unfuelled mass: 1007 kg (2,220 lb).
Thrust to weight: 112.5 to 1.
Status: Study 1967.
Height: 1.25 m (4.10 ft).
Diameter: 2.97 m (9.74 ft).

Now, an 8.4 m diameter toroidal engine at the base of this composite tank has 8x the thrust of the J2-2T-250K - to produce 2 million pounds of thrust. 909.1 metric tons of thrust (8.9 mega-Newtons)producing 441 seconds Isp. (4,324 m/sec exhaust speed). The mass is 8 metric tons. This is 1967 level of performance. The X-33 program saw a 45% increase in performance so we can expect 1,318.2 metric tons of thrust at this Isp.

The Inflatable Reentry and Descent Technology (IRDT) demonstrator was launched on Soyuz-Fregat on 8 February 2000. The inflatable shield was designed as a cone with two stages of inflation.

http://www.spaceflight.esa.int/irdt/factsheet.pdf

A similar system built into the nose of a Space Shuttle External Tank sized composite tank would mass 2.9 tonnes.

http://www.astronautix.com/graphics/z/zirdtiss.gif

and slow the ship to subsonic speeds,

And would use a relatively small 30 tonne aerospike engine at the nose for soft landing down range - this engine masses 0.3 tonnes.

This is the simplest version. A more complex version involves the use of ILC dover inflatable wings;

http://www.engr.uky.edu/~fml/papers/05WAC-61.pdf

Which add another 3 tonnes to the flight system, but give the tank the ability to be air-towed back to the launch center by a recovery plane loitering down range.

Composite Tank 15.9 tonnes
Re-entry System: 2.9 tonnes
Boost Engine: 1.0 tonnes
Landing Engine: 0.3 tonnes
Wings: 3.0 tonnes
----------------------------
TOTAL 22.0 tonnes

This is lighter than the original Al-Li tank without the add-ons! Still carrying 734 tonnes of LOX/LH - and attaining 4.34 km/sec exhaust speed.

Now, propellant fraction to attain 9.20 km/sec orbital speed (7.9 km/sec actual speed, 1.3 km/sec air drag and gravity loss) is;

u = 1 - 1/exp(9.2/4.34) = 0.7145

I made a mistake here - this should be 0.87995


propellant fraction

and we have 734 MT propellant mass - so

TOW = 734/0.7145 = 1027.2

So, the TOW is reduced to

TOW = 734/0.87995 = 834.1

When we solve Calc of Variation problem we'll need something like 1.28 gee at lift off for optimal performance. So, we need 1,314.8 MT at lift off. A shade under what our performance is.

This changes the thrust at take off to; 1,067.6 metric tons

So, subtracting off our inert weight and propellant weight from our take off weight we obtain our payload;

p = 1027.2 - 22.0 - 734.0 = 271.2 metric tons (598,250 lbs!)

Which becomes

p = 834.1 - 734.0 - 22.0 = 78.1 metric tons (172,288.6 lbs!)

Still bigger than the Saturn V payload!

With cross feeding, and using this as a common core booster, we can get even more performance.

This is something that could have been done any time after 1970 had we the sense to do it!

Some call this fantasy, yet its all 1970s engineering! The fact the major aerospace companies have extensive capabilities in this area and have developed COMMERCIAL USES for that - suggests USAPs using the technology are flying.

Using this as a starting point for a common core booster,

In article ,
says...

William Mook wrote:


A careful review of capabilities and publications indicate that aerospace vendors since about the 1970s have had the ability to achieve 2% structure fraction with LOX/LH2 propellant combination and have also had the ability to create advanced aerospike engines that seamlessly operate as a rocket at subsonic speeds and as an external combustion ramjet and scramjet at higher speeds.


Cite? You truly don't understand the point of an aerospike engine, do
you?

snip remaining Mookspew unread

He's not only missed the point entirely, he's confused the very basic
operation of a rocket engine with those of air breathing engines. :-(

Mook completely and absolutely missed the mark on this one.

Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

On Saturday, January 24, 2015 at 11:16:27 AM UTC-5, Jeff Findley wrote:
In article ,
says...

William Mook wrote:


A careful review of capabilities and publications indicate that aerospace vendors since about the 1970s have had the ability to achieve 2% structure fraction with LOX/LH2 propellant combination and have also had the ability to create advanced aerospike engines that seamlessly operate as a rocket at subsonic speeds and as an external combustion ramjet and scramjet at higher speeds.


Cite? You truly don't understand the point of an aerospike engine, do
you?

snip remaining Mookspew unread

He's not only missed the point entirely, he's confused the very basic
operation of a rocket engine with those of air breathing engines. :-(

The aerospike is an altitude compensating engine that changes its expansion ratio with altitude as air pressure changes. Anyone who thinks the aerospike operates totally and completely independently of the atmosphere has failed to understand the advantages of the aerospike operation.

A vehicle with an aerospike engine uses 25-30% less fuel at low altitudes, where most missions have the greatest need for thrust. Aerospike engines are the baseline engines for many single-stage-to-orbit (SSTO) designs and were also a strong contender for the Space Shuttle Main Engine.

Now, the aerospike is easily converted to an air-augmented rocket. Air-augmented rockets use the supersonic exhaust of the aerospike rocket engine to compress air collected by ram effect during flight to use as additional working mass, leading to greater effective thrust for any given amount of fuel than either the rocket or a ramjet alone.

Air-augmented rockets are a hybrid class of rocket/ramjet engines, similar to a ramjet, but able to give useful thrust from zero speed, and is also able to operate outside the atmosphere, with fuel efficiency not worse than both a comparable ramjet or rocket at every point.

Running the exhaust oxygen rich (which is true for the case of a LH2/LOX combination running at 5.5:1 O/F ratio (fuel rich compared to stoichiometric) leads us to consider additional combustion of fuel in the air surrounding the engine to gain additional thrust.

This is the scramjet engine. Scramjet engines operate on the same principles as ramjets, but do not decelerate the flow to subsonic velocities in order to burn fuel using incoming oxygen. Rather, a scramjet combustor is supersonic.

Now the simplest approach is not to slow the air AT ALL. This reduces drag and heating to a minimum. What one does is eject fuel into the EXTERNAL air flow so that the fuel is at rest relative to the air, and the REMOTELY DETONATE the air fuel mixture over an EXTERNAL THRUST STRUCTURE.

To do this efficiently requires structuring the detonation of air/fuel as a SHAPED CHARGE to create PROPULSIVE DETONATION WAVES against the aerospike thrust structure.

In this way, the modest aerospike gives far more than 25% improvement in performance.


Mook completely and absolutely missed the mark on this one.

No, as per usual, you have completely missed the mark, and are too proud to admit it, so project your shortcomings on to me and denigrate me for your stupidity.

Time to grow up dude.


Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer

On Saturday, January 24, 2015 at 4:30:49 PM UTC-5, William Mook wrote:
On Saturday, January 24, 2015 at 11:16:27 AM UTC-5, Jeff Findley wrote:
In article ,
says...

William Mook wrote:


A careful review of capabilities and publications indicate that aerospace vendors since about the 1970s have had the ability to achieve 2% structure fraction with LOX/LH2 propellant combination and have also had the ability to create advanced aerospike engines that seamlessly operate as a rocket at subsonic speeds and as an external combustion ramjet and scramjet at higher speeds.


Cite? You truly don't understand the point of an aerospike engine, do
you?

snip remaining Mookspew unread

He's not only missed the point entirely, he's confused the very basic
operation of a rocket engine with those of air breathing engines. :-(

The aerospike is an altitude compensating engine that changes its expansion ratio with altitude as air pressure changes. Anyone who thinks the aerospike operates totally and completely independently of the atmosphere has failed to understand the advantages of the aerospike operation.

A vehicle with an aerospike engine uses 25-30% less fuel at low altitudes, where most missions have the greatest need for thrust. Aerospike engines are the baseline engines for many single-stage-to-orbit (SSTO) designs and were also a strong contender for the Space Shuttle Main Engine.

Now, the aerospike is easily converted to an air-augmented rocket. Air-augmented rockets use the supersonic exhaust of the aerospike rocket engine to compress air collected by ram effect during flight to use as additional working mass, leading to greater effective thrust for any given amount of fuel than either the rocket or a ramjet alone.

Air-augmented rockets are a hybrid class of rocket/ramjet engines, similar to a ramjet, but able to give useful thrust from zero speed, and is also able to operate outside the atmosphere, with fuel efficiency not worse than both a comparable ramjet or rocket at every point.

Running the exhaust oxygen rich

I meant to say FUEL rich here, not OXYGEN rich... correction.

(which is true for the case of a LH2/LOX combination running at 5.5:1 O/F ratio (fuel rich compared to stoichiometric) leads us to consider additional combustion of fuel in the air surrounding the engine to gain additional thrust.

This is the scramjet engine. Scramjet engines operate on the same principles as ramjets, but do not decelerate the flow to subsonic velocities in order to burn fuel using incoming oxygen. Rather, a scramjet combustor is supersonic.

Now the simplest approach is not to slow the air AT ALL. This reduces drag and heating to a minimum. What one does is eject fuel into the EXTERNAL air flow so that the fuel is at rest relative to the air, and the REMOTELY DETONATE the air fuel mixture over an EXTERNAL THRUST STRUCTURE.

To do this efficiently requires structuring the detonation of air/fuel as a SHAPED CHARGE to create PROPULSIVE DETONATION WAVES against the aerospike thrust structure.

In this way, the modest aerospike gives far more than 25% improvement in performance.


Mook completely and absolutely missed the mark on this one.

No, as per usual, you have completely missed the mark, and are too proud to admit it, so project your shortcomings on to me and denigrate me for your stupidity.

Time to grow up dude.


Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer