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The SR-71 Spy Plane Was So Fast, It Outran Every Missile Fired at It (nationalinterest.org)
188 points by jrs235 59 days ago | hide | past | web | favorite | 170 comments

I don't know much about aviation, but I know there's a plane that was faster than the SR-71: The X-15 [1].

I know because my great uncle died flying the X-15 on an experimental flight [2], so it's always been an interesting story for my family.

[1] https://en.wikipedia.org/wiki/North_American_X-15 [2] https://theaviationgeekclub.com/the-story-of-mike-adams-the-...

I find it absolutely incredible that the piloted speed record set by this aircraft - set in October 1967 when William J. Knight flew Mach 6.7 - hasn't been broken in 50+ years.

It's a mix of things I think. First we haven't had a really big breakthrough in engine technology in a while and second there's no need to risk a person piloting these anymore because computers and remote control tech has gotten good enough.

Wouldnt the scramjet engines be a pretty big breakthrough?

Scramjet still needs air though, doesn't it? Thus it has to fly lower, and maybe can't get as fast as a rocket engine.

Scramjet planes are faster than other non-rocket planes I would imagine?

The SR-71 cruised at Mach 3.2. Scramjets have been demonstrated to do Mach >5, and theoretically might be capable of something between Mach 17 to Mach 25(!!!)

Scramjets do need air, although something to consider is that the faster you go, the more air you get. So at high altitudes with very thin air, you can go faster to get more air. In fact you have to go faster (true airspeed) in thin air anyways even if your brought along liquid oxygen for your engine, because as the air thins your stall speed will go up.

The whole thing is a complicated system of equations. Engine capabilities and/or critical mach number (for planes designed for subsonic flight, like the U-2) of the airframe set an upper limit on how fast you can go. Air density decreases with altitude, increasing the stall speed (according to true airspeed, not indicated airspeed.) But for a given true airspeed, with increased altitude the temperature of the air drops, consequently dropping the speed of sound, which reduces the mach number. In subsonic planes as altitude goes up the stall speed and critical mach number eventually pass each other, beyond which your plane can no longer fly. The point of that intersection is known as the 'coffin corner'. In planes designed for supersonic flight passing the critical mach number isn't a problem, but eventually you'll reach a point where the drag on the aircraft is so great that the engines simply don't have enough power to overcome it. Increasing altitude reduces drag as the air gets thinner, but that only works for so long. Air speed inside the engines needs to be considered too. The airspeed past the turbine blades needs to be such that you won't get compressor stall. When you discard the turbine requirement, that's where things start to get interesting. A ramjet has no turbines, it compresses the air using the intake geometry. At full speed the SR-71 was actually producing most of it's thrust with a ramjet effect, most of the air going into the engines was not going through the turbines. The difference between a ramjet and a scramjet is that in a ramjet, the air inside the engine becomes subsonic again for the burn, but in a scramjet the air inside the engine remains supersonic. Scramjets could go really fast.

If we put a cockpit and a pilot in it the X43A would have broken the crewed record at Mach 9.6 back in '04 but there was no need because we have computer controls now for these test flights and there's not a huge number of uses for having pilots in these insanely fast planes partially because they're just so insanely fast.

I think the hypersonic planes will all be drone munition delivery (or just munitions themselves) for a long time. Maybe some day they'll carry people but there's no supersonic aviation much less hypersonic and even then the piloting at speed will probably be all automated.

Yes, scramjets are faster than other non-rocket planes. They have a lower bounds of approx. Mach 3, but then go up from there.

The big challenge is basically making sure that you mix your fuel with the air, combust it fully, and extract the energy before it flies out the back of the engine. Scramjets are the engines capable of this at the highest speeds.

Maybe because once you start going faster than that there isn't much point staying inside the atmosphere? If you want to count spacecraft that record has been shattered.

It is like the land speed record. As soon as you get over a couple hundred miles per hour you might as well fly.

So when you get to mach 6 you might as well be in space....

And when you get to about mach 33 you might as well leave orbit.

There’s a huge new interest in hypersonic gliders.

The speed record for a car over a kilometer has not been broken since 1937 [1]

[1]: https://en.wikipedia.org/wiki/Mercedes-Benz_W125_Rekordwagen

How do you know?

Man! Hacker News is so interesting with folks like you hanging around.

"Plane" is a bit of a misnomer for the X-15, though. "Rocket with wings" is more accurate.

There are some (mostly Brazilians) who would disqualify the Wright Flyer as the first airplane on the grounds that it took off from a rail. Is the engine breathing air really an essential part of the "airplane" definition? Solar Impulse 2 didn't breath air either, yet wasn't it an airplane too?


It's certainly a glider on reentry. Now, most speed records for planes are "in level flight" which would disqualify the shuttle during reentry. But if we ignore that it's interesting that the speed record for manned aircraft is held by a glider, and the speed records for RC aircraft are also held by gliders! https://www.youtube.com/watch?v=MoaWlKC3wIM

The authoritative body for aircraft records is normally Fédération Aéronautique Internationale and I believe the SR-71 is in Class C as a Aeroplane while the X-15 is a Class P Aerospacecraft.

So as far as "Official" speed records go the fastest "airplane" is a Sr-71. Its technically the fastest manned air breathing aircraft.

There seem to be some semantic ambiguities between Aircraft, Airplane, Rocket, etc.

The X-15 also wasn't launched from the ground which seems a pretty significant distinction from a plane as well.

I think more technically the Wright Flyer was the first powered flight. People had been flying guiders successfully for decades before.

Technically that was probably New Zealander Richard Pearse, not the Wright brothers.


His flight was a bit... crashy. The Wrights managed a fully controlled powered flight first, but even then their "first flight" wasn't as far as Pearce's flight had been nine months earlier. And it also ended in a crash.

Not the "first powered flight". That honour probably belongs to Henri Giffard.

Typically the Wright Flyer is credited with "the first sustained and controlled heavier-than-air powered flight" or something similar.

If you add enough qualifiers you can be first at anything.

Is the space shuttle a plane?

The NASA Shuttle, no, the Soviet Buran, yes.

As a Brazilian (see previous comments about the Wright Brothers), I consider that an airplane:

* Is powered, otherwise, it's a glider;

* Can maintain level flight, otherwise, it's just "Falling with style";

* Can take off on it's own, assistance (RATO, catapults) is allowed for short take-offs (like from a carrier);

The Shuttle fails in all that in some point of the flight or another, Buran on the other hand, could be fitted with air breathing jet engines that allowed it to do all that.

...falling with style

I like Douglas Adams' description: The ship hung in the sky in much the same way that bricks don't.

> Can take off on it's own, assistance (RATO, catapults) is allowed for short take-offs (like from a carrier);

Well, by that definition I think the X-15 isn't a plane - it required a B-52 mothership to launch after all. IMO it's hard to find a definition of "plane" that includes the X-15 but not the Space Shuttle stack (not the orbiter on its own - the full stack).

Was the Buran ever actually flown with air-breathing jet engines or is this purely hypothetical fantasy like most of that program?

Before the OK-1 unit did it's unmanned flight, several prototypes were built to test different aspects of the craft, one of these had jet engines and made atmospheric flights, including taking off on it's own.

Not exactly the same Buran that flew, but its atmospheric analog during training and development:


That's pretty cool, I didn't know they did that.

Could the Shuttle not be fitted with jet engines? Or do you mean there was no official spec to actually do that, whereas with the Buran there was?

Nope. Rocket only.

And on descent it was gliding, not under its own power.

I feel like a basic requirement for a plane would be that it can maintain its altitude, so no?

There is a nice example now in popular culture of the problems of a X-15 in the beginning of the movie "First Man" with Neil Armstrong bouncing off the atmosphere in this rocketship.

The other popular case, the only lost ship was also similar to the bad MCAS system in the Boeing 737max, the pilot forgot to turn off the problematic flight control system, and he didn't see the 90 yaw angle because he turned it off, so he raced straight down, and the control SW kept it that way.

Is there any single piece of technology that's more retro-futuristic than the SR-71? It is undefinably iconic especially if you understand what happened behind the scenes. Lockheed's Skunk Works managed to not only look into the future, but they managed to make it manifest in the past.

The first one took flight over fifty years ago and we still talk about it as if they represent the promise of the future. As a culture and community, we rarely view Project Apollo in the same way. To me, in contrast to the Blackbird, our first step outside our cradle looks dated. The Saturn V is an ode to the sheer force of will required to send human beings to another heavenly body. It certainly looks the part. The Blackbirds, on the other hand, were precise, surgical instruments designed to cut borders and they look the part. Every element of the plane ends in that sharp-looking edge. There are no blunt surfaces on it. It’s one complex curve wrapped around itself and stretched into that timeless shape.

And that's before you pull back on the curtain. I don't have online sources for this, but I have read books about the project that explained how every single part within the Blackbirds - from the engines to the paint - was brought into being for this project. They set out to do something so daring and so pioneering that they had to invent new alloys to do it. And then they had to build the machines to work that alloy: new machines - tape-based robots - to precisely carve it into shape, new procedures to put it together, and new philosophies to let it fly. These planes were designed to fly so fast that ordinary Titanium-based alloys would melt or weaken over time leading to rapid, unplanned disassembly. They didn’t have more advanced ceramics which could do the job, so Kelly Johnson’s team came up with a new alloy that was annealed - or re-tempered - in flight, so that it became stronger and stronger over time. Theoretically above some classified altitude the Blackbird can go much faster than Mach 3 and keep on going until the airframe melts away at some crazy high, theoretical speed no one has bothered to check.

They did all of that in a past where the most sophisticated engineering tool in common use was a slide rule and the first scientific pocket calculator was nearly a decade into the future.

Do you ever wonder when we'll build something so daring that it will finally eclipse this project? I do. Paraphrasing Thiel, "what happened to the future? We were promised Blackbirds and got the F-35 instead."

> Paraphrasing Thiel, "what happened to the future? We were promised Blackbirds and got the F-35 instead."

It's kinda weird how the F-35 just looks somehow dated and like a slob compared to e.g. the older (and cooler looking) F-22. Though perhaps "cool looks" is maybe not the prime factor in fighter jet selection...

Kelly Johnson, who led the project to build the Blackbird, disagrees. "All of us had been trained by Kelly Johnson and believed fanatically in his insistence that an airplane that looked beautiful would fly the same way." --- Ben Rich, Skunk Works

This quote opens an essay on beauty by Paul Graham, http://www.paulgraham.com/taste.html

Believe he also had to be convinced by Rich to support the boxy F-117A.

The F-117 was mostly a limitation of computing technologies at the time. We (apparently) didn't have the horsepower to model radar hitting curved surfaces, so the boxy plane came as a result of the limitations of the modelling system.

Function follows form?

They merge at a point. The moment they merge you have achieved Nir... Unix ideal.

> Though perhaps "cool looks" is maybe not the prime factor in fighter jet selection...

The urban legend about why the X-32 lost out to what become the F-35 is it having a stooopid looking mouth on it: https://i.imgur.com/1GW21we.jpg

The x-32 was just happy to be there. Like a big metal basking shark.

Since the selection of the JSF was during the Clinton presidency, the X-32 was often referred to as Monica.

Some mean looking teeth, or a spooky spiral may have changed that.

The F-22 outperforms the F-35 in virtually every aspect. It's possible to stick F-35s 360 thermals on the F-22 too.

It does have some pilots who are real fans of it:

If you were to write down all the ways in which you could measure an airplane—payload, fuel, ordnance, handling—and ask 100 pilots to rank which is the most important, I guarantee you that 100 out of 100 pilots would say “situational awareness.” By far. Not a single pilot in the world would say “turn radius.” Not one. Because the more you know, the more accurately you know it, the better able you are to make a decision.

In situational awareness, the F-35 is superior to all platforms, including the Raptor. I’d never been in an airplane that so effectively and seamlessly integrates information to tell me what’s going on around me—and not just from the radio frequency spectrum, but laser, infrared, electro-optical. That’s usually the first thing people notice when they get in the airplane. They know so much more than they ever knew before.


You can stick every sensor on the F-35 onto the F-22. It would not be difficult to do so. Now, the question of why they haven't, is an interesting one. And part of the answer is that EODAS is not performing as well as promised.

It would be extremely hard to do. The F-22 bus is antiquated, and not really designed for expansion. That's one of the reasons the F-22 still doesn't have an IRTS.

First of all, I can't prove my opinion.

With that said, if push came to shove, the electronics on the F-22 could be quickly replaced/augmented to either have a focused IRST ala the SU-35 or a 360 system like F-35's EODAS. Your argument is in line with "It would be difficult to restart the F-22's production line." Sure, but neither doing that or updating it would cost nearly as much as the amount of money that went into the F-35.

I think IRST wasn't made a priority because the US expects to have AWACS wherever they operate and the F-22s to shoot based on AWACS data without ever actively emitting themselves anyway. That or planes toggling radar one at a time and passing data via datalink to their squadron, which makes them fairly safe (at least that was the idea with datalinks).

Then why are people buying F35s?

EDIT: Thanks everyone, I wasn't aware that the F22 had a higher price and additional export restrictions.

Cost. The F-22 costs $200M+ per plane. The F-35 cost $94M for the small initial production runs, and that's expected to come down as production volumes go up and the program cost (which includes large fixed costs like software and tooling) gets amortized over the production run.

One F-22 vs one F-35 is a contest obviously in favor of the F-22. One F-22 vs. three F-35s becomes a lot more ambiguous, particularly when we are not at war and there's no guarantee that any of these planes will do anything more than force projection.

(The F-35 very much seems like a peacetime fighter to me, and that may be exactly what the U.S. needs right now. History has shown that basically all your assumptions about how the next war will unfold go out the window once the next war actually starts. Under those conditions, it may make more sense to try out a bunch of new technologies, keep the defense contractors alive and the aeronautical engineers employed, contain costs, and build enough numbers that you don't get completely steamrolled in the early days of a war. Then when war actually does break out, you rapidly adjust and build the planes that you actually need, when you have real data about what's winning on the battlefield.)

"History has shown that basically all your assumptions about how the next war will unfold go out the window once the next war actually starts."

Also, don't forget that nuclear weapons still exist. Nuclear powers shooting down squadrons of each others fighters to achieve "victory" does not seem likely.

Controversial opinion here, but I think nukes are going to be an evolutionary dead-end in the history of weaponry. Either they'll end up getting used, in which case "WW4 will be fought with sticks and stones", or more likely they won't end up getting used because everybody knows that's the outcome, and we'll have more conventional proxy wars where everyone just pretends nukes don't exist.

Other controversial opinion: I think that the assumption that the next major war will be between nation-states is a likely candidate for one that'll go out the window. In my view, the next major war will be like Syria but on a global scale, with many semi-organized subnational groups duking it out in exceptionally nasty urban & guerilla warfare.

I thought those were both mainstream opinions.

1. F22's are banned from being sold to anyone but the US.

2. F22's are only fighter jets. F35 for better and worse is designed to do just about everything.

The F-15Es do better in strike roles than planes that weren't supposed to be pure fighters.

The motto of the F-15 when it was initially designed was "not a pound for air to ground."

Sure, but Han shot first.

We sell the F-35 because if it ever came to it, our F-22's would dominate their F-35's they bought from us.

But to be fair, as the other comments have pointed out the F-35 is lower cost, a decent peace time machine and is has flexible configurations.

For the same reason people buy Corollas when Audis are available. Even with all the troubles the F-35 has had, the F-22s still have a substantially higher unit cost.

The F-22 also can't be sold as an export.

Only version available for export, about half the price.

It is supposed to be the cheaper stealth fighter.

You don't need high turn rates when you have Electro-Optical Distributed Aperture System (EODAS) like the F-35's cueing High-Off Bore-Sight (HOBS) short-range air-to-air missiles like the AIM-9X.

From what I've heard, the fact that the X-35 looked cooler than the X-32 was a non trivial component of it being selected in the JSF program.

And why not? With the multitude of ground based missiles fielded today, a considerable part of the role of fighter aircraft is status. Imagine a programme as expensive as the F-35 that resulted in a plane so ugly that you'd want to hide it. It would be objectively worse at projecting power without actually fighting it out even if it had slightly better performance characteristics.

Oh sure, I'm not expressing judgement.

Given a volunteer military, and remembering their advertising in high school, they probably want people to feel as cool as possible joining up too.

That's a damn shame because the X-32 is easily one of the world's cutest airplanes.

Delivering death with a smile.

if "cool looks" was a factor, IMHO the YF-23 is near the top.

Yes, amazing looking aircraft. Never seen more beautiful lethality in an airplane.

I've always thought it was a shame the YF-23 wasn't developed into the role eventually filled by the F-35. It had a lower radar cross-section than the F-22, could supercruise faster, had better range, and with the deletion of the afterburners (not necessary for the revised role, especially when you can truck along at M1.8 without them) it could have opened up a lot of space for additional weapons storage.[0] And it was a long way to being a developed aircraft. Could have been finished much more cheaply than the F-35, no doubt.[1]

[0] Not sure of the CG shift implications, though.

[1] Not sure if those savings would have been eaten up by higher operating costs.

Well, the F-23 was never going to be VSTOL, nor take off a carrier. So it never would have fulfilled the roles of the F-35. It would have been a nice replacement for the F-111 and Strike Eagle however.

I remember an artistic rendering of the A-12 Avenger when I was younger. I thought it was the coolest plane I had ever seen.

"If it looks right, it flies right"

Quote I've heard attributed to WW2 pilots, but google isn't helping me with.

> Do you ever wonder when we'll build something so daring that it will finally eclipse this project?

We can't do that kind of engineering anymore. Computers have made us ... lazy? That's not really the word. With so much computing power at hand, we just don't have the pinpoint focus that it would take to make another SR-71 and not hobble it with over engineering and feature creep. Or even just being able to let go of a nagging problem. For example, a proper sealant couldn't be found to keep the fuel from leaking so they just said whatever and let it leak fuel until it warmed up. Nobody would do that today.

The real problem is that the mission the SR-71 was built for doesn't exist anymore, and nobody else with a need to go that fast has the money to back it up. We could build a successor the SR-71 that would go even faster and further and have fewer weird issues like fuel leaking out constantly, but it would cost a lot more (even inflation adjusted) than the SR-71 did and fulfill a mission that nobody was asking for.

Computers didn't make us lazy, but the Git-R-Done mentality of the old projects got gobbled up by the bureaucracy in all of our big defense contractors/aerospace companies. It's super hard for a Kelly Johnson type to fend off thousands of middle managers all trying to justify their position.

The SR-71 was replaced by satellites.

The F-35 is a giant weird beast because it's massively multi-mission, but really as a backstop to what we can't do with drones, missiles, and satellites.

> The F-35 is a giant weird beast because it's massively multi-mission

No, it's multimission because new airframe types for manned combat aircraft that could meet evolving demands were becoming giant weird beasts and getting exponentially more expensive (something that typically happens with classes of systems as they become unviable) anyway, and doing one airframe for almost every conceivable role was envisioned as a means of containing costs.

Containing costs -> multi mission -> giant weird beast. I don't think we disagree.

Still, I think the point about it being a backstop to unmanned aerial assets stands. I don't know if it needs to be optimized for any single mission when it's likely to be a worse choice than one of those assets.

> doing one airframe for almost every conceivable role was envisioned as a means of containing costs.

Didn't they learn from the Phantom that one airframe for all tasks simply doesn't work ?


> but really as a backstop to what we can't do with drones, missiles, and satellites


Will it not be most likely the last manned fighter jet?

Doubt it. If it is remote controlled, you have to deal with latency and are susceptible to jamming and/or hacking and I doubt AI will be good enough for many years to come to be completely reliant on.

> "Is there any single piece of technology that's more retro-futuristic than the SR-71?"

Maybe not more, but up there with it are the Concorde, and the H&K G11.

Also, if you like the SR-71, check out the A-12. The immediate predecessor of the SR-71, very easy to confuse the two, with the notable exception of the A-12 having a single seat. I think that makes it even cooler. Just one pilot, no other aircrew, up there alone with the machine. That's really incredible to me.

+1 on the G11. Any bullpup rifle already looks reto-futuristic; combine it with caseless ammunition, the ability to fire a 3 round burst in 80ms before buffering happens and the 90 degree rotating feeding system, and you've got something that still feels sci-fi today.-

I was not familiar with A-12 and looked it up. Wow.

With the wingtips are folded up, the A-12 looks like something out of Star Wars.

The triangular shape is reminiscent of B-2 Spirit, though these are of course completely different beasts. Both the A-12 and B-2 were designed during roughly the same era, late 1980s. I guess there was some kind of cross-pollination of ideas (maybe via DARPA) for a triangular design to appear like this?

I think you and GP are discussing different A-12's. GP is referring to the Lockheed A-12 https://en.wikipedia.org/wiki/Lockheed_A-12 and you are referring to the McDonnell-Douglas A-12 https://en.wikipedia.org/wiki/McDonnell_Douglas_A-12_Avenger...

Don't even bother trying to figure out US military naming schemes.

I suspect that the reason the A-12 and the B-2 looked alike is that there is enough similarity in mission that the best shape ended up that way. (Or as an old friend used to say, "aerodynamics can't lie.")

Aye, the Lockheed A-12. It was apparently the 12th iteration of the CIA's "Archangel" program, hence "A-12."

Knowing the CIA, that designation may have been misdirection too. 'Main battle tanks' are called 'tanks' today because of WWI era misdirection. Instead of calling them "armoured tractors" or something descriptive like that, the British called them "water carriers." The abbreviation of that (w.c.) was considered crude though, so they were renamed "tanks" as in a container for carrying water. This was to ensure any German spy who overheard the wrong conversation would get the wrong impression.

Oh yeah, you are right.

The Lockheed A-12 has a familiar appearance... I always thought it somehow looks like a flying dragrace car. Everything in it screams "fast".

And as for the "wrong" (McDonnell-Douglas) A-12, another thing I found interesting was that some of the modern drone designs also have the same triangular shape. (Like X47-B, X45-C/Phantom Ray, nEUROn, RQ-170)

And the X47-B can even fold its wings!

Talk by the A-12 pilot, Frank Murray. Refers to the SR-71 as the "family model".


I'd throw in the H&K XM25 grenade launcher on the list as well. Wouldn't be out of place in a sci-fi movie.

The SR-71 is amazing in many ways. It can't start it's own engines, they are started one at a time by a huge generator that drives under each wing. Adding to what you said about the skin of the plane, what I heard is that the skin isn't sealed until it's flying... that the SR takes off with a minimal fuel load, because it literally leaks fuel, and then gets refueled immediately. It's no wonder people speculate there was other-worldly inspiration.

Most military aircraft at the time and for a while after could not start themselves. I think everything on the deck when I served on a carrier in the late 80s except maybe s-3s required huffers and electric carts to get going.

The startup of an F-22 using it's jet fuel starter is pretty wild: https://www.youtube.com/watch?v=JUO-D2-OfDQ

Thank you for your service!, and for sharing.. I didn't know that.

Most aircraft, really. That's why jet engine "air start" services are provided at most airfields and airports.

> Theoretically above some classified altitude the Blackbird can go much faster than Mach 3 and keep on going until the airframe melts away at some crazy high, theoretical speed no one has bothered to check.

I'm very skeptical of these rumors. The SR-71 inlets were shaped for a specific range of mach numbers, and wouldn't work beyond that. Significant new engineering would be needed to go well beyond mach 3.5.

Using MagnetoHydroDynamic, you can. You just have to use parietal Engine invented by Jean-Pierre Petit in 1975[1]. With this technology you can fly at Mach 8, easily..

[1] https://www.youtube.com/watch?v=Jn8b3E9oUHY

> With this technology you can fly at Mach 8, easily..

In an SR-71?

Ah, I was mistaken.

Love the SR-71 and recently visited Kelly's gravesite when I found it was in the neighborhood.

However, the economics of never really made sense in regards to its utility. Only during the cold war could such a project be dragged into the realm of possibility.

F-35 is a massive success compared to UAVs. It's the only supersonic aircraft with VTOL capabilities that also simultaneously has stealth capabilities. HN constantly complains about manned fighters being obsolete but Global Hawk et. al. cost more than a F-35 per unit and they can at most only be used against ground targets that don't fire back.

>...ordinary Titanium-based alloys would melt or weaken over time leading to rapid, unplanned disassembly.

That's a rather understated way of saying "She'll fly herself apart!"

I should be working, but your comment was enthralling.

I had the good fortune to hear Bill Weaver (pilot of an SR-71 that underwent a midair unplanned disassembly) tell his story.



It bothers me to see so many projects overbudget and late, even to do mediocre things like combine a city's disparate accounting systems. Were companies better in the past?

There is a great podcast that covers this question....


I love reading about skunk works! Any specific books you can recommend?

Well, there is the book called "Skunk Works" written by Ben Rich. It's very good.

I loved the story about the F-117 (the hopeless diamond) in radar testing not showing up on the screen, so the radar operator told someone to go check to see if the model fell off the stand. That guy stuck his head out the door and was about to say "no it's still there" when a bird landed on the model and the radar operator said "Oh, I see it now"

I love this book, the accounts from the pilots (humourous and anxious) are incredible. Growing up I read this multiple times and it never fails to be a great read.

Some of my favorite stories include the fact that you could take off in the morning, fly up to the arctic circle, and back down in time for dinner in the evening.

Agreed - this is an incredible book. Highly recommend it.

More Than My Share Of It All by Kelly Johnson, himself (well, through a ghost writer)

YF-12 development film. Check out the avionics test.


> Do you ever wonder when we'll build something so daring that it will finally eclipse this project?

Maybe we have, and just haven't been told about it.

This was a joy to read, I am getting goosebumps and this feeling running down the spine when we as humans do something extraordinary. Truly extraordinary.

Eh. Weapons of maintenance of American military hegemony aren't exactly my idea of the pinnacle of human ingenuity.

It certainly looks cool though.

Technically, it is. Don’t throw political and philosophical burden and anti-American stance when we are discussing technical achievements.

The parent comment simply talks about engineering challenges and it’s frankly amazing.

I don’t think we will in the US. We are too self hating right now.

There was a story where Trump basically tried to get NASA to try and do a manned mars mission within 10 years. He said he’d offer them an unlimited budget. They said no.

Now, feasibility of any of this aside: that just depresses me more than anything I’d heard in a long while. You won’t even try? C’mon! What happened to “we are doing it not because it’s easy, but because it’s hard”? The mentality that we can do literally anything we put our minds to?

Look at the way that people want to vilify Elon Musk. Here’s a guy that embodies everything I grew believing was the American spirit, and apparently that makes him a bad guy. So sad.

>“But what if I gave you all the money you could ever need to do it?” Trump reportedly asked. “What if we sent NASA’s budget through the roof, but focused entirely on that instead of whatever else you’re doing now. Could it work then?”

"Cancel all your research projects and focus on a rushed, unsafe, mission to Mars within the next four years" isn't an offer I'd take either.

And that's even supposing he has the political power to actually give them the money he was offering. Which he doesn't.

I don’t think I’d take your uncharitable version of the offer either!

Also, many folks don't realize that going to Mars would be much harder than the Moon for multiple reasons. There are several big engineering problems not yet solved and n. Nasa knows this.

There's a Tyson show on it, perhaps still on Netflix if interested.

> Now, feasibility of any of this aside: that just depresses me more than anything I’d heard in a long while. You won’t even try? C’mon! What happened to “we are doing it not because it’s easy, but because it’s hard”? The mentality that we can do literally anything we put our minds to?

They are going to try. Just a month before, Trump himself had signed a bill outlining a manned Mars mission, and the timeline to actually do it.

What they said no to was a spur of the moment request, made without discussing feasibility (or anything else about it) with anyone else before making it, to do it way way way faster than that.

Here's an article with the details [1].

[1] http://nymag.com/intelligencer/2019/01/trump-offered-nasa-un...

Can you source the Trump story? In the Atlantic [1], it looks like Trump asks NASA if they can do it by the end of his first term with unlimited budget, so that's 4 years instead of 10 years. (10 years is still very short for a manned Mars mission.)

NASA is an enormous entity with many different branches, and each aerospace mission must be planned and funded carefully. Upper management at NASA must also consider the politics of a situation; what would happen to NASA if they agreed to such an offer and failed to deliver results?

This seems like it was a political move by Trump that allowed him to look good by making a risky request. If NASA says "yes" and gets to Mars, Trump wins. If NASA says "yes" and fails to get to Mars, Trump says "I gave the money and you didn't do your part". If NASA says "no", Trump says "I offered them the money but they didn't take it".

[1] - https://www.theatlantic.com/science/archive/2019/01/trump-ma...

There is an unbelievably good interview with Brian Shul, one of the only SR-71 pilots to take a bunch of pictures of the plane[1]. He tells the story about when his commander asks him to fly right up to the soviet border to get their anti-air radars to light the blackbird up. He asked what he should do if they shot missiles at it and his commander said to just turn around and outrun it. He was quite skeptical of this and very amusingly describes this real life encounter. He's a really funny speaker.

[1] https://www.youtube.com/watch?v=BZRP1q1PGUk&t=33m0s

UPDATE: Video with better sound thanks to https://news.ycombinator.com/item?id=19505767 I found the specific story I was referring to at 33m

+∞. I watch this anytime I need motivation. This guy is the epitome of not letting anything get in his way. Such a good public speaker and amazing career! Cannot upvote that video enough.

Here's one with better sound: https://www.youtube.com/watch?v=BZRP1q1PGUk

Thanks updated! (33m0s is the story I was referring to)

A friend of mine served in the Air Force on the refueling planes that serviced the SR-71s. He said that it was hard for the refueling plane to go as fast as the SR-71's slowest speed! So they did the refueling in a shallow dive, to give the refueling plane a boost.

The SR-71 flight manual can also be found here [0].

I was surprised to find the plane can be flown solo [1], and with no pressure suit below 50,000 feet [2].

There is also a section on "Tactical Limits" describing scenarios where exceeding normal operating limits is advised to exit a hostile area [3]

0. https://www.sr-71.org/blackbird/manual/

1. https://www.sr-71.org/blackbird/manual/5/5-23.php

2. https://www.sr-71.org/blackbird/manual/5/5-23.php

3. https://www.sr-71.org/blackbird/manual/3/3-135.php

Link [3] is hilarious in how banal it is- the same of the manual describes both how to defog your windows and how to GTFO if under hostile missile fire.

> I was surprised to find the plane can be flown solo [1],

Doubtlessly a consequence of the A-12 being flown solo. The SR-71 was a derivative of the A-12.

There is a few really great stories about the SR-71 on the internet, many out of the book "Sled Driver". I would not (as it is customary on other parts of the internet) leave the full copy-pasta here, but I do recommend the "air speed check) story (to be found e.g. at https://oppositelock.kinja.com/favorite-sr-71-story-10791270... ) and the low fly-by (e.g. at https://foxtrotalpha.jalopnik.com/the-sr-71-blackbirds-most-...).

I re-read the "air speed check" story every time it's posted. It never gets old.

Same here!

I first came across the story here on HN, and every time someone mentions it I re-read it. It truly never gets old; only now I just got goosebumps. I think it's the people bonding part that gets me.

I think there is a lesson here that applies to more than just planes. Speed often can solve a problem in a simple way.

The enemy will fire missiles at us. What shall we do? (1) Invent missile-proof armor, (2) Build computer-guided anti-missile lasers, (3) Just fly really fast.

I guess all of those are hard to do. Making the SR-71 fly at Mach 3 wasn't easy. But to me it seems more elegant.

In the early 2000s, Google made a big deal about speed in web apps. I think it still does, but I don't hear about it anymore. And everybody knows that GMail is slower. But I appreciated it while it lasted.

This resonates with how I like to solve problems. Instead of thinking about how we can fix it or mitigate it, how can we make it impossible for a certain kind of problem to occur? Maybe it's just my procrastination speaking but I find it easier to just wipe out entire kinds of issues.

To me the most interesting part of this article is that I missed there was a contract awarded for a Mach 6 SR-72, that may or may not already have a sighted test platform.

I wish more SR-71 stories focused on the sensors and defensive systems. Although not a sexy as the aircraft, in some ways the SR-71 could be considered a "sensor truck." Post-mission processing and analysis of raw data was a huge part of the total SR-71 program. The system and sensor manufacturers were on the cutting edge of airborne reconnaissance and remote sensing. Good page on some of the sensors here: http://www.sr71.us/sr_sensors_pg3.htm

My favorite story about the Blackbird is how it was designed with heat and expansion in mind.

On the ground to leaked fuel like a sieve[1][2], it was only once it reached operational speed that the joints & frame heated up and sealed it, (thus requiring a refueling shortly after take-off). [1] https://www.sr-71.org/blackbird/sr-71/ [2] http://physicsbuzz.physicscentral.com/2011/02/betrayed-by-he...

The ground crews, I'm told, hated this plane because it leaked toxic fuel everywhere while on the ground and was otherwise a pain to deal with.

These sorts of stories are what impress me about programs like this. No commercial product could ever be so expensive, so difficult, so wildly impractical. The military are practically the only ones who can do things like this, because the need is so great it justifies all the craziness. I work at NASA and we do crazy things like sending robots to Mars, but that seems tame compared to the insanity of something like the SR-71.

The other major reasons they didn't load much fuel on the ground is that the engine fuel economy at low speeds and low altitudes was atrocious. After refueling, the crews would head for the cruising altitude as soon as possible.

Y’all should really go to the National Museum of the US Air Force. You’ll see almost all of the planes mentioned here there. And it’s free. Nothing like seeing Blackbird in person as well as all the other planes. Plan on a full day at the place.

One of the authors, David Cenciotti, also has a nice aviation (primarily military) weblog [1] and made some interesting speculation about that stealth Blackhawk [2].

1. https://theaviationist.com/

2. https://theaviationist.com/tag/stealth-black-hawk/

There's a Lockheed A-12 on the USS Intrepid that you can get very close to with a guided tour. One of the facts the tour guides tell you about it is the titanium for the planes, as well as that of the SR-71s, was mostly sourced from Russia via shell companies for all kinds of bullshit reasons. So, America flew spy planes over Russia that were made from materials mostly of Russian origin.

I don't know the full veracity of this piece, but IIRC the Foxbat once acquired a lock on it: https://theaviationist.com/2013/12/11/sr-71-vs-mig-31/

Plenty of things acquired a lock on it, including ground-based SAM sites. That's the easy part.

The USSR pilot claims:

“Had the spy plane violated Soviet airspace, a live missile launch would have been carried out. There was no practically chance the aircraft could avoid an R-33 missile.”

The pilot also claims the lock was from 120km, which is the maximum range of the R-33 at the time, so I'm a bit dubious of the idea without a practical demonstration.

I do suspect the "surround from all directions" approach detailed later would've worked, but that's why we moved off to stealth and satellites.

Here are some relevant and IMO very interesting videos for your viewing pleasure:


https://www.youtube.com/watch?v=-5nSKLyrM1s (long talk by SR-71 pilot Maury Rosenberg mentioned in the first video)

https://www.youtube.com/watch?v=CeBu6mRDaro (an even longer talk by another SR-71 pilot Richard Graham)

If you're into this kind of stuff the book Skunk Works by Ben R Rich is REALLY good! IMO it carries a lot of lessons into software development and startups also. Like they did random startup type things where for example the external starter motor for the planes engines was made from a couple Buick motors. They spent lavishly where they had to but were frugal and kept it simple where they could. Fun + interesting read.

apparently "no Blackbird of any variety has ever flown over the landmass of Russia or China", according to former SR71 pilot Col. RH Graham.

so we don't really know if they have the capability, but after they downed the U2 in 1960, seems the US didn't want to find out empirically.

that said, you have to love this plane. it's a spaceship.

I recall reading a story of flying an SR71 through the cloud from a Chinese nuclear test. We wanted to know if it was a fusion weapon or not.

The Chinese sent up a fighter after it, and, well, it wasn't fast enough. It also had too low of a ceiling.

Can't cite a source (I read about this, what, four decades ago?) so I can't prove it happened.

If you haven't heard the "SR-71 Speed Check" story, it's pretty amusing. As told by the pilot: https://www.youtube.com/watch?v=8AyHH9G9et0

Remember the U2, the predecessor that was shot down famously. https://en.wikipedia.org/wiki/Francis_Gary_Powers.

A bit unrelated , but would someone please explain how come missiles fired from Stinger MANPADS are so fast?

They really aren’t. They can only get up to ~750 m/s.

You want fast, take a look at the Sprint missiles. The damn things had 100g of acceleration and could hit 3400 m/s.

Did you say Sprint missiles?


I do actually follow him, but I hadn’t seen that yet.

They're small, light weight, and about 80% fuel. Without a squishy human on board, rockets can accelerate very quickly.

On paper it would out run any missle with prior warning. But in reality in a dog fight at close range its unlikely it would be at top speed to do so quickly enough.

There is no such thing as "dogfight at close range" with an aircraft that travels at Mach 3+ when cruising into enemy territory.

Even the slightest turn at those speeds moves the airplane by 10s of miles.

Any attempt to intercept or shoot down planes that fast happens at great distances and is totally dependent on computers, radar, and missiles.

It wouldn't get much time to spy at that speed, it has to slow down at its destination and it's fuel limits won't allow great distances without speed changes. Top speed is different from real speed

You're badly misinformed on the SR-71.

> It wouldn't get much time to spy at that speed

That's why you take photos and do the spying part back on base. The SR-71's weapon was its sophisticated camera setup.

> it's fuel limits won't allow great distances without speed changes

When it set its speed record, it crossed from LA to DC on one tank of fuel. (It tanked up immediately after takeoff and immediately before landing, but the cross-country flying part didn't involve a tanker.)

Opinion: SR-71 does not deserve its records.

There are many faster objects, including the X-15 and Shuttle. Both are faster than the Blackbird but do not count. Shuttle is a spacecraft but even during reentry, shuttle could not hit such speeds unaided by other aircraft that departed from it along the way (the boosters etx). Nor could the X-15 which was dropped from a larger carrier aircraft. Both could not get to their records speed unaided.

Neither could the SR-71/YF-12. They burnt so much fuel getting off the ground that, to preform a run to top speed and get home, they needed to refuel. So how is that fundamentally different than Shuttle or the X-15? For an aircraft to qualify as an aircraft it should be able to get up and down without help. Therefore it is the Mig-25/31 that deserves the praise of "fastest aircraft".

This is an urban legend. Landing it when it was almost empty was gentler on the landing gear, so they took off with relatively little fuel in case the mission was scrubbed.

They could have taken off and accelerated to record-breaking speeds if that's all they wanted to do, but the typical mission profile was to fly to far away locations to conduct surveillance, so in-air refueling was always part of the mission profile.

That's not the information I've seen. From what I've read a fully-loaded takeoff and climb would burn so much fuel, far more than a typical profile, that it would still not have been able to break records set by the migs.

That sounds dubious to me. The SR-71 had some massive tanks and the idea that it couldn't accelerate to full speed on one tank seems unlikely. Even if you account for the burn in climbing to 50k feet ASL it seems like it has to be underselling the Blackbird quite a lot.

These two claims aren't mutually exclusive.

This article summarizes why they refueled after takeoff: https://theaviationgeekclub.com/former-sr-71-driver-explains...

TLDR: They needed full tanks (more or less) or an inert layer of nitrogen over the gas in the tanks before hitting Mach 3 or else the fumes in the tank might ignite. At the end you'll see that they had a system for fueling the tanks on the ground in order to hit mach 3 right after takeoff but it was a maintenance nightmare.

If I remember right, the SR71 could fly at Mach 3 for up to 90 minutes between refuelings. That's significantly longer than any jet ever made.

>> significantly longer than any jet ever made.

Except the XB-70. Data is rare, but it was to cruise at 3.0 for somewhere between one and two hours.

"Somewhere between one and two hours" sounds a lot like 90 minutes.

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