Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

thedrive.com

Post reply on HN
Print view View original

41–50 of 160 posts

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#41

Post by DuskStar »

treggle wrote: post #11

Of course, because nothing matters more than getting the advantage. Same line of thinking that results in depleted uranium tank shells.

> Same line of thinking that results in depleted uranium tank shells.

Yeah, since neither was particularly toxic, and both offered significant performance gains over the alternatives. (Uranium is extremely dense, self-sharpens on impact instead of mushrooming, and catches fire after penetration giving you an incendiary payload for free. Supposedly, nothing else comes close for tank rounds)

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#42

Post by willvarfar »

blackflame7000 wrote: post #25
galangalalgol wrote: post #21

Earlier quoted context omitted.

The kingfish looked like something more modern than an f-117. The f-16xl that lost to the f-15e looked like a modern European design. The boeing jsf was... Ugly, but the grumman one was cool looking. Its kind of a trend, the losers are so much cooler.

You can definitely see the B2 exhaust design in the Y23. It seems the Northrop gets the bombers and Lockheed gets the fighters. Makes sense logistically.

Nothing about modern fighter procurement makes any sense logistically!

It seems the F22 was basically picked on the promise to make as many components in as many separate states as possible, in order to ensure every politician on the hill brought into it.

And the idea of servicing different parts of the F35 in different buying countries is another logistical masterstroke, not! Oh my god, servicing F35 engines in Turkey just when Turkey starts to dance with Russia, what were we thinking?

Right now we're telling Turkey you can't have the F35 because you've just brought the S400 SAMs from Russia, but we've already invested in servicing the F35 engines there...

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#43

Post by mgarfias »

aidenn0 wrote: post #15
galangalalgol wrote: post #8

Earlier quoted context omitted.

The sr-71 gets all the glory but go look at some of the aircraft that lost competitions. The convair kingfish that lost to the 71 was decades ahead. It lost for a number of reasons, some valid, some not. The f-22 competitor was super interesting as well.

Yeah, the YF-23 wins a lot of cool points on looks alone[1], and it was faster and stealthier than the F-22. Taking the -22 was probably the right choice given that it was lower risk and absurdly better than anything it's likely to encounter in its operational life. 1: https://en.wikipedia.org/wiki/Northrop_YF-23#/media/File:YF-...

Funny, the way i remember it happening: both YF-22s were lost do to mishaps, the YF-23 was faster, stealthier, and just as maneuverable without the vectored thrust. The AF wanted the -23, but the chairman of the senate armed services committee was from Georgia, where Lockheed promised to build the -22. and the history got rewritten.

Source: Dad was part of the YF-23 program at northrop and lost his gog when the project was shitcanned. yes, still bitter almost 30 years later.

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#44

Post by nullc »

My experience with cesium is that everyone thinks its radioactive. It isn't-- like many common elements there is a radioactive isotope, but that is not what would have been used here.

I speculate this worked by the highly reactive cesium ionizing the air. Similar things have been done with doping rocket fuels with metals to stimulate lightning strikes.

Presumably most of the cesium would end up reacted very quickly, I don't know what the products would be but plenty of obvious candidates like cesium carbonate appear to be non-toxic.

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#45

Post by willvarfar »

leeoniya wrote: post #18

my favorite A-12 read: https://www.otherhand.org/home-page/area-51-and-other-strang... that whole site is full of awesome accounts of his adventures out west.

My favorite A12 talk:

https://www.youtube.com/watch?v=MGdxpqqsHl8

Frank Murray's talk is full of great facts, insight, yarns and stuff. Still as sharp as a tack.

There are lots of other interviews with A12 and SR71 and other interesting planes on youtube.

Be warned: an HNer could lose days browsing there ;)

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#46

Post by dr_dshiv »

jhayward wrote: post #30
treggle wrote: post #11

Of course, because nothing matters more than getting the advantage. Same line of thinking that results in depleted uranium tank shells.

I have some bad news. We used to put tetraethyl lead in automobile fuel and then burn it in cities next to homes and schools.

And when we took the lead away, crime dropped like 50% https://en.m.wikipedia.org/wiki/Lead%E2%80%93crime_hypothesi...

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#48

Post by jazzyjackson »

IcePenguin wrote: post #12
vvanders wrote: post #9

Earlier quoted context omitted.

Some of the stuff to restart the afterburners was pretty nasty too. I think it was one of the hypergolic families if I remember correctly.

Yep! It's called TEB (Triethylborane). More info here: https://en.wikipedia.org/wiki/Triethylborane JP-7 has a very high ignition temperature (it was actually used as a coolant/heat sink for the rest of the aircraft), so TEB combusting once it hit the air is used to light the engines. SR-71s only had a limited amount of TEB to use each flight. I believe it was 13 shots per engine. TEB was used each time the engines w…

I don’t know anything about afterburners, if it’s the same fuel as the usual engine, what about it needs to be lit with a lower temperature fuel?

I always assumed afterburners just meant opening the throttle up but there must be more to it

Re: The SR-71's predecessor used cesium-laced fuel to create radar-absorbing exhaust

#50

Post by faizshah »

taneq wrote: post #31
tlb wrote: post #7

> It’s also not clear from the available records how much [cesium] was necessary per gallon of [jet fuel] Come on, you lazy reporter! Go find a jet engine and some cesium and a radar reflectometer and make a graph of reflectance vs. cesium content. Presumably, some engineer at Lockheed in the late 50s got exactly that assignment, with a budget. There would be a notebook with a table of numbers and a hand-drawn graph.…

I would love to see some kind of web database of old engineering notebooks like this, surely there are enough now kicking around in boxes of "grandad's junk".

Some cool ones here: https://www.computerhistory.org/collections/fairchild/

Would be cool to see some old notebooks from Bell Labs tho like Ritchie or Thompson. I just found some old AT&T training manuals on Perl, TCP/IP, Bash, C and Unix internals, they are really cool.

Post reply on HN