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Aurora speculation thread (rational discussion only pls)
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After a chat with Stingy via email she has allowed me to create this topic under the condition that we keep this discussion on a rational level. Besides I need a hard aerospace discussion in my life right now because of the coronavirus lockdown and im going P Swayze here lmao. If we can centre our exchange around the known facts as much as possible and avoid random anecdotal bs, i think this thread can adhere to the general forum rules regarding speculative discussions.

So the aerospace community on the subject of Aurora can be divided into these groups...

1. those who don't believe in its existence nor any reported sightings and insist that its only a myth, end of discussion.

2. those who entertain the possibility, but are highly sceptical (hence this topic)

3. those that believe, but are sceptical about the nature of it and may have some plausible theories (also hence this topic)

4. absolutely believe and have many wild theories that are beyond the realm of reality, like reverse-engineered alien tech and stuff.

If we can stay in the range of no 2-3, that would be just lovely TY. :)

What we know thus far...

"Aurora" is absolutely unlikely to be the craft's real name! The story begins in March 1990 when Aviation Week revealed the name "Aurora" connected to a US DOD funded 455 million dollar "black aircraft production" in 1985. According to Ben Rich (former Skunk works director) the name was randomly stuck to the B-2 when the programme was still under wraps then got leaked to media. It was just a budgetary code name not referring to any specific design.

right, so back in the late 80's it was hypothesized that the US had the capability of developing hypersonic successors to the Blackbird. There were plenty of sightings being reported then and around the 90s about unidentified craft and other such phenomena of this nature. Ever since the name leak, these sigtings were referred to by Aurora ever since.

Today we have access to sooooooo much more information on hypersonic tech and former black projects than back in those days, which i think could help construct some plausible theories and would really make this discussion interesting. :)

Thoughts?



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Except a thread on Aurora will likely spur discussion based on anecdotal evidences since no hard evidence to prove OR disprove it exists. Hypotheticals on reverse-engineered alien tech would be as valid as any other speculation since there aren't any verifiable references to go on, only best guesses. Who is to judge who's guesswork is more logical over the other? Kind of a slippery slope IMHO.



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Clearly it was swamp gas.



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AURORA A orbital spy system that dropped the film canister for pick up by air craft equipped with Fulton airborne grapple -

Father worked for Steward Davis testing the stresses applied to the cables in the operation [Air Force Contract]

On one test they paid out the cable with 1500 lbs on the end and the cable separated, through the clouds they saw the boat for Catalina Island below.

near miss,,,,,\./,,,,,,

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I hope that what I can offer is constructive enough to fit the thread's criteria.

I consider myself one of the folks that believe in Aurora, but I also accept that the truth is probably a lot more boring than others make it out to be. Bill Sweetman's examination of the defense budget does reveal that there is a lot going on behind the scenes and provides for an interesting lead, but it doesn't exactly point to a single black project. The sightings can have alternate explanations as well. I've seen things flying over the Nevada desert that I couldn't explain myself, but I also don't claim to have a flawless mental index for aircraft recognition.

That being said, I do find some of the reports interesting, like the unusual seismic phenomenon and ATC radar signatures that were characteristic of a vehicle exhibiting hypersonic flight technology.

I try to keep an open mind.



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Rafale D wrote:

 Kind of a slippery slope IMHO.


 "slippery slope" fallacy in argumentative logic infers that a minor event or idea would lead to a largely negative outcome or chain of events, i think you mean a reification?

granted most "evidences" available are purely anecdotal but at the risk of sounding like an appeal to authority, the reports come from rather credible sources rather than garden variety hatters. 

Personally i hypothesize that some of the sightings may have actually been the F-117 since it fits the delta winged / flying triangle shape generally and is appropriate for the era of the earliest sightings. the other phenomena is possibly unrelated, maybe connected to the SR-71? dunno. :/



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I'll bite.

How about the SR-72? This is a legit proposal for a successor to the SR-71 from Lockheed and it was reported around the early 2000s... I wonder if the earlier sightings might be prototype aircraft. The shape looks like a match to most of the Aurora concept art all over the net.



-- Edited by Pepper on Wednesday 8th of April 2020 02:17:45 PM

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Leela25 wrote:
Rafale D wrote:

 Kind of a slippery slope IMHO.


 "slippery slope" fallacy in argumentative logic infers that a minor event or idea would lead to a largely negative outcome or chain of events, i think you mean a reification?

granted most "evidences" available are purely anecdotal but at the risk of sounding like an appeal to authority, the reports come from rather credible sources rather than garden variety hatters. 

Personally i hypothesize that some of the sightings may have actually been the F-117 since it fits the delta winged / flying triangle shape generally and is appropriate for the era of the earliest sightings. the other phenomena is possibly unrelated, maybe connected to the SR-71? dunno. :/


 Well either way judging the best guesswork seems counterproductive but that's my viewpoint.smile

@Pepper...SR-72 was never built and the 2007 reports are unsubstantiated. I'm willing to go along with the SR-71 theory though, since it has been in service in the 80's and until the late 90's, and I'll also include the theory of it being the F-117 for the visual sightings. So I agree with Leela25 in that the reports could very likely be pointing to separate phenomenon.



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Pepper wrote:

How about the SR-72? This is a legit proposal for a successor to the SR-71 from Lockheed and it was reported around the early 2000s... I wonder if the earlier sightings might be prototype aircraft. The shape looks like a match to most of the Aurora concept art all over the net.


 this is more of a case of form following function, like Rafale D said no prototypes were ever built. BUT i can entertain the possibility of other test aircraft meant to be successors to the SR-71 in hypersonic technology, before the SR-72 was proposed. Highly speculative (as to be expected of such hypotheses) but its an interesting thought. :)



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Another what-if: highly modded experimental variant of the SR-71.

And another: highly modded experimental variant of the F-117.

Is this feasible from an engineering or aerodynamic standpoint? Is it more cost effective than a new airframe?



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Rafale D wrote:

@Pepper...SR-72 was never built and the 2007 reports are unsubstantiated. 


 I wouldn't necessarily call them unsubstantiated since they were technically confirmed when the proposal was unveiled in 2013. Lockheed was studying the design long before they attached a name to the concept.



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Pepper wrote:

Another what-if: highly modded experimental variant of the SR-71.

And another: highly modded experimental variant of the F-117.

Is this feasible from an engineering or aerodynamic standpoint? Is it more cost effective than a new airframe?


 Doing this would in the end result being overhauling the airframe to be able to accommodate the design of its reported capability in which you might as well have invested the time and money into a whole new airframe.

The stress of hypersonic speed needs to be considered for the airframe to be structurally sound, first of all, and you need a sutable surface with minimal drag and that allows the equal distribution of frictional heat plus a way to manage heat internally which, second of all creates the issue of the type of fuel and suitable powerplant... in the most feasible artist's impressions you'll see that the combined cycle ramjet or pulsejet designs utilize a common breathing system accommodated throughout the whole underside of the fuselage (essentially all-body layout) where air is compressed to expel enough thrust through the nozzle for a high cruising speed. At this range we are looking at thermal conditions of around 760 C internally and externally, so this creates the issue of high energy output from the powerplant in just cooling the system alone. Common hypothetical solution: cryogenic fuel. Methane and liquid hydrogen are a logical choice in this matter since the fuel type for the SR-71 lacks the sufficient heat absorption (kerosene derived jet fuel types like JP-7 can't allow higher than a little over the range of mach 3) but have a low density and require appropriate accommodation e.g. large enough fuel tanks. In all liquid methane would be the most efficient with high heat absorption plus higher density than liquid hydrogen and statistically can support speeds around mach 7.



-- Edited by Leela25 on Wednesday 8th of April 2020 05:13:46 PM

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1997 driving back from the state line near Vegas after a jug change in the field on the S-58 -
Driving along in the after noon and in the middle of nowhere the whole truck imploded the oil buckets in the bed jumped, the 1820 engine hopped up 4 inches the dirt on the floor blew up to the seat.
Pulled over and looked to see if the road had a big bump in it. nothing.
Oil all over lose engine tied back down, continued home.
Never saw what caused the 'sonic boom'
Was it the Aurora ?

What if you used a nose spike to make a shockwave barrier to shield the airframe from the hyper sonic air? Ride the wave...

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There was a 1997 report about sonic booms in Kentucky and other places nearby too, but it could be anything really. 1996-1997 is when the Aurora buzz started to fade out because there were less reports being made about sightings and other phenomenon, leading to the belief that it was just a short-term experimental type or family of types... or people just stopped caring and gave up making a thing out of it lol :P

 

hillberg wrote:

What if you used a nose spike to make a shockwave barrier to shield the airframe from the hyper sonic air? Ride the wave...


 What youre referring to is called a drag reducing aerospike, its designed for blunt nosed objects to form a displaced shockwave ahead of the forebody that creates a recirculating flow for the object. This is not to be confused with the aerospike engine which is a kind of altitude compensating rocket engine (ive seen people confuse the two when talking about hypersonic aerodynamics before and so i feel obligated to clear this up for any of the uninitiated that happen to be reading this)

The design is very effective for missles based on the rounded nosecones being needed to reduce frictional heat, while also requiring a streamlined body to reduce drag, the result being a displaced shockwave that stretched past the stabilizing surfaces and reduced friction and drag, essentially "riding the wave" like you put it lol. It would also result in a significant noise reduction. The method is employed on ICBMs like the Trident... in fact tests were done in 1995 with aerospike equipped missiles that were reported able to achieve teh speed of mach 6 in order to evaluate the feasibility of hypersonic missiles. Theoretically this method could be used on manned hypersonic vehicles and tests were done with similar nosecone spikes on manned aircraft around the early 2000s (see Quiet Spike.)

Here are major problems with this relating to Aurora...

The hypersonic body needs to conform to the capabilities of the aerospike to achieve maximum effectiveness. Current iterations are designed for cylindrical objects like missiles that can travel through the displaced wave with minimal surfaces exceeding the boundary, i.e. wings or a widened fuselage that would reintroduce frictional heat and drag. Yes you can design a hypersonic fuselage to conform to this issue and there have been some proposals in recent times, but thats not the point im making. The point is that it was only in recent times that things like this were becoming considered for manned hypersonic vehicles, waaaayyy after the Aurora reports. None of the sightings describe a fuselage shape that entails these kind of aerodynamics. And with reports of unusually loud booms and "pulsing" roaring noise (like a pulsejet), it doesnt make sense for a shockwave displacement method that would *reduce* noise levels!

Its a neat thought though. :)



-- Edited by Leela25 on Saturday 11th of April 2020 05:26:35 PM

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Not sure how an aerospike would modify the sound emanating from whatever engine type it used, but I agree that it would muffle the effect of the shockwave itself and make a quieter boom. A streamlined surface shouldn't disrupt the flow from the displaced wave since I don't think the wave is narrow enough for this to be an issue. Especially if the aircraft has a blunt nose, it would spread further than the widest points.



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I'm quoting my questionable memory but I think I remember reading reports that the SR-71 went through wind tunnel tests with an aerospike, probably not the same one in most of the mainstream photos because I'm sure that's a data probe. I could be wrong. I most likely am. Why am I posting. Delete this post. Ban me forever. Take away my social security benefits...



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Further reading into the Chris Gibson sighting in the North Sea gave me an idea just now. Compare his sketch to the Northrop LAP (Low Altitude Penetrator) concept. Similar isosceles triangle shape and it fits the era. These drawings are from the 1980 DARPA study featured in the B-2 Systems Engineering Case Study. The LAP was one of two Northrop designs that were proposed to fulfill separate roles of the low-observable strategic bomber concept, one for high altitude and the other low altitude. The high altitude design was selected and modified for both roles which eliminated the LAP design and became the B-2. This could be a stretch but what if it actually was considered and a flying example did exist?



-- Edited by Pepper on Monday 13th of April 2020 09:48:54 PM

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Roots could be drawn from this 1979 Boeing proposal also.



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Pepper wrote:

I'm quoting my questionable memory but I think I remember reading reports that the SR-71 went through wind tunnel tests with an aerospike, probably not the same one in most of the mainstream photos because I'm sure that's a data probe. I could be wrong. I most likely am. Why am I posting. Delete this post. Ban me forever. Take away my social security benefits...


 le banned forever! Poor Anthony, confusing your aerospikes again. x3

You're talking about the NASA LASRE (Linear Aerospike SR-71 Experiment) when it was tested with an aerospike engine, it was part of a programme to study reusable launch vehicles and was a part of the Lockheed X-33 development. Theres a crapton of info online.

 

Pepper wrote:

Further reading into the Chris Gibson sighting in the North Sea gave me an idea just now. Compare his sketch to the Northrop LAP (Low Altitude Penetrator) concept. Similar isosceles triangle shape and it fits the era. These drawings are from the 1980 DARPA study featured in the B-2 Systems Engineering Case Study. The LAP was one of two Northrop designs that were proposed to fulfill separate roles of the low-observable strategic bomber concept, one for high altitude and the other low altitude. The high altitude design was selected and modified for both roles which eliminated the LAP design and became the B-2. This could be a stretch but what if it actually was considered and a flying example did exist?


 I had considered this too, for the Gibson sighting but i didn't entertain it in this thread because of why it wasnt considered, which was mostly because having two separate designs wouldnt have been cost or operationally effective and the LAP was limited in its overall capability, which made modifying the M/HAP for low altitude operation a better alternative. To hypothesize that time and money and so much research was put into building a prototype demonstrator anyway doesnt make much sense. It would be redundant especially after the B-2 was built and capable of both roles.

now, to say the design may have inspired other delta shaped low observable platform studies, its quite possible but... who knows :P

Pepper wrote:

Roots could be drawn from this 1979 Boeing proposal also.


 Maybe. but not a direct connection since it was proposed without prior knowledge of there already being a low observable bomber programe and was dropped.



-- Edited by Leela25 on Tuesday 14th of April 2020 03:07:44 PM

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Leela25 wrote:
Pepper wrote:

Further reading into the Chris Gibson sighting in the North Sea gave me an idea just now. Compare his sketch to the Northrop LAP (Low Altitude Penetrator) concept. Similar isosceles triangle shape and it fits the era. These drawings are from the 1980 DARPA study featured in the B-2 Systems Engineering Case Study. The LAP was one of two Northrop designs that were proposed to fulfill separate roles of the low-observable strategic bomber concept, one for high altitude and the other low altitude. The high altitude design was selected and modified for both roles which eliminated the LAP design and became the B-2. This could be a stretch but what if it actually was considered and a flying example did exist?


 I had considered this too, for the Gibson sighting but i didn't entertain it in this thread because of why it wasnt considered, which was mostly because having two separate designs wouldnt have been cost or operationally effective and the LAP was limited in its overall capability, which made modifying the M/HAP for low altitude operation a better alternative. To hypothesize that time and money and so much research was put into building a prototype demonstrator anyway doesnt make much sense. It would be redundant especially after the B-2 was built and capable of both roles.

now, to say the design may have inspired other delta shaped low observable platform studies, its quite possible but... who knows :P

Pepper wrote:

Roots could be drawn from this 1979 Boeing proposal also.


 Maybe. but not a direct connection since it was proposed without prior knowledge of there already being a low observable bomber programe and was dropped.



-- Edited by Leela25 on Tuesday 14th of April 2020 03:07:44 PM


 Well that destroys the hypersonic theory doesnt it?smile

NLAP wasn't designed for Mach 6 speeds it was for low altitude operations as an answer to contemporary Soviet detection and surface-to-air threats. Using it or any of the real life Flying Dorito designs for hypersonic travel would be an engineering nightmare and the trailing edge would be highly detectable without adequate RAM, making it a bad candidate for stealth operations too.



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When did she say anything about the LAP being designed for mach 6 speeds? That really came out of nowhere.

You even both agreed on the sightings and sonic booms being separate phenomenon, yes? How does her explanation of the LAP design have anything to do with the hypersonic theory when she wasn't even drawing a connection between the two?

 

Leela25 wrote:
Pepper wrote:

I'm quoting my questionable memory but I think I remember reading reports that the SR-71 went through wind tunnel tests with an aerospike, probably not the same one in most of the mainstream photos because I'm sure that's a data probe. I could be wrong. I most likely am. Why am I posting. Delete this post. Ban me forever. Take away my social security benefits...


 le banned forever! Poor Anthony, confusing your aerospikes again. x3

You're talking about the NASA LASRE (Linear Aerospike SR-71 Experiment) when it was tested with an aerospike engine, it was part of a programme to study reusable launch vehicles and was a part of the Lockheed X-33 development. Theres a crapton of info online.


 Well I feel dumb now. Thanks for correcting my crap memory. In hindsight I probably should've researched that before posting, especially since putting the research work into those Northrop studies.



-- Edited by Pepper on Wednesday 15th of April 2020 12:01:46 AM

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Don't sweat it we all have our moments. Like me so desperate from boredom that I started an Aurora thread... im starting to regret it. x_x

Rafale D's watch was probably running a little slow when he wrote his comment too. Of course it would suck for hypersonic travel, me and Anthony were simply speculating about one of the sightings which we already concluded probably not having anything to do with the other reports. IIRC Chris Gibson was a bit irritated with his sighting being roped into the Aurora buzz himself, but we can thank Bill Sweetman for that ( his book on Aurora is a really neat read though!)

I really lean towards the Have Blue/Senior Trend/F-117 being the subject of the sighting most of all, if not some super secret modded one (not hypersonic like you speculated, Anthony) plus maybe for other sightings and the SR-71 responsible for other phenomenon (the supersonic/hypersonic reports). The B-2 should not be left out of the equation either. These are the most rational speculations that I can come up with given what is publicly known but i am open to the possibility of black programmes just because black programmes are a real thing. Maybe with some time passing data will become declassified and we will finally have answers. Until then the myth and the stigma behind it lives on unfortunately. :P



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Well my comment on a highly modded F-117 was more generalized if anything, it wasn't limited to the discussion about hypersonic capability. The F-117 would explain the isosceles triangle shape a lot, and you're likely correct about the B-2. The relationship between the two designs being that they could explain a majority of flying triangle UFO reports from that time.



-- Edited by Pepper on Monday 20th of April 2020 01:29:25 PM

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Pepper wrote:

The relationship between the two designs being that they could explain a majority of flying triangle UFO reports from that time.


 Nuuuuuu those were the super secret X-project DARPA stealth blimps powered by marmite and xenomorph scat dont you know anything?? :P



-- Edited by Leela25 on Sunday 26th of April 2020 06:02:55 PM

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Vegemite engines are more fuel efficient, just saying.biggrin



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:O  heresy! instabanned!!!



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biggrin

By the way I apologize for straying off topic for a moment, but I want to go back to the discussion on aerospikes. Leela, you mentioned the aerospike engine further up this thread. I was wondering why the linear aerospike is not a practice over using standard bell type rocket engines? From what I understand a rocket or turbojet would increase efficiency with an aerospike since it adjusts to variable air pressure with differential thrust, it is lighter and consumes less fuel = an efficient answer to conventional space shuttle engines and could be an aswer to efficient hypersonic vehicles.



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An Aurora thread on this forum? Times are a changin'!

I'm half expecting this discussion on aerospikes to somehow coalesce with the "donuts on a rope" contrails. They always seem to.



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retroistic wrote:

An Aurora thread on this forum? Times are a changin'!

I'm half expecting this discussion on aerospikes to somehow coalesce with the "donuts on a rope" contrails. They always seem to.


 IKR?? what was i thinking *headdesks*

Only hatters who have not a clue what an aerospike is would connect the two. The pulsejet explanation is equally absurd. Sometimes i see both theories mashed together. Doughnut contrails happen wih anything that make contrails... they are commonly caused by turbulence or ambient wind conditions.

So you see we still havent lost our minds while you were away! :3

or maybe we did ? did we have them to begin with?? ;o

Rafale D wrote:

biggrin

By the way I apologize for straying off topic for a moment, but I want to go back to the discussion on aerospikes. Leela, you mentioned the aerospike engine further up this thread. I was wondering why the linear aerospike is not a practice over using standard bell type rocket engines? From what I understand a rocket or turbojet would increase efficiency with an aerospike since it adjusts to variable air pressure with differential thrust, it is lighter and consumes less fuel = an efficient answer to conventional space shuttle engines and could be an aswer to efficient hypersonic vehicles.


 In short?

1. they are a massive engineering hassle for what theyre worth (see no 5)

2. they are very expensive to build and integrate, again for what they're worth (see no 5)

3. they are NOT lighter, for the most part. They can be significantly heavier with rocket engines despite the reduced profile from a conventional bell nozzle, but turbojets may find more benefit regardless of the weight penalty. Unless it is fully integrated into the system though, like on the Lockheed X-33 then the weight is reduced a lot... weight is a variable from the specific design, really... they are not just all universally lighter.

4. they ARE fuel efficient yes, but with this comes the issue of high temperatures and another engineering hassle in figuring out an effective cooling solution. Besides what if you used it as a reentry shield? it could work in theory but good luck dealing with the frictional heat on top of everything :)

5. they don't really work. Ok, they do partially but not enough to be worth it. Yes they are a one-up from conventional engines because they adapt to ambient pressures at varying altitudes sufficiently but at the cost of some pretty negative factors. And they reduce base drag a little bit, woooo. Bottom line theit total efficiency is nothing too spectacular.

In the end better fuel efficiency and partial base drag reduction are overshadowed by too many negatives to make them worth regular usage, especially facing the factor of cost... if its not the least bit cost effective its essentially a dead end. Most of the time anyway... :/

Maybe not as short of an answer that i planned but it does the job xD



-- Edited by Leela25 on Monday 4th of May 2020 04:20:47 PM

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Informative answers are the best kind, thank you.smile

Now to be constructive : Why would you want to use it as a re entry shield when the SSTO lifting body is designed with adequate heat shielding? Besides, even if you did, I think that if it can withstand the extreme temperatures of rocket thrust it can handle atmosphere friction. The fuel type could also play a part in temperatures, if you used a denser type with higher heat absorption it should aid in temperature reduction. My impression is that an aerospike is flexible between solid and liquid fuel and should be able to handle a cryogenic fuel type. You seem to have a better grasp of rocket science tho so I'm eager for some schooling.

How did they handle these problems on the SR-71 aerospike and what was the overall conclusion?



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