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Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

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Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#21

Post by danielvf »

mikestew wrote: post #14
hansjorg wrote: post #11

Earlier quoted context omitted.

It's not mentioned in the article, but I guess this means that compass navigation wasn't possible at the time?

Not without aviation charts, which the article does mention were in short supply back in the early days of aviation. That, and I'm willing to bet that the licensing for pilots less than twenty years after the Wrights took off at Kitty Hawk was less than rigorous. So assuming that a licensed pilot, if such a thing even existed, was well-versed in navigation via charts and a compass was likely wrong.

Even perfect charts would have been useless - the early airmail mail flew at night, in bad weather, with single pilots in open cockpits.

Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#24

Post by fizzbatter »

djsumdog wrote: post #9
SCHiM wrote: post #2

tl/dr: U.S. Military spy satellite camera calibration.

> "This [X] we're standing on right now helped protect us from nuclear war," Owen says. Um no. It just helped the US know where shit is. They didn't keep us safe. Mutually assured destruction did. That's why every war since then has been a proxy war. If anything, programs like this poured massive amounts of money into expanding out out of control military and probably caused the expansion of wars into areas, leading…

I mean, isn't that a bit pedantic? If you go down that route, MAD didn't keep us safe either, it's our enemies belief/knowledge that we had weapons of mass destruction, that kept us safe. etcetcetc

It's all part of it. Without intelligence (from dozens of source) to act upon, and Americas enemies believing we could find meaningful targets and/or hit them, MAD wouldn't really exist. Same goes for not having the tech to launch the nukes. Or a hundred other things.

It all helped, to one degree or another, and that is all they said. "This [X] we're standing on right now helped protect us from nuclear war".

Am i missing your point?

Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#25

Post by fizzbatter »

strictnein wrote: post #15

One of the most interesting things about the Corona satellites was that they shot on film and that film was developed back on earth. So how'd they get that film back down from space? https://en.wikipedia.org/wiki/Corona_(satellite)#Recovery

Answered here: https://news.ycombinator.com/item?id=12695808

Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#26

Post by nitrogen »

Bronze_Colossus wrote: post #12
mslev wrote: post #3

I love stuff like this, I just think its so cool. Similar to this are the large cement arrows across the US: http://www.cntraveler.com/stories/2013-06-17/transcontinenta...

Here is a few more picture more: http://www.messynessychic.com/2013/11/15/the-forgotten-giant... I also find these kind of things cool. Forgotten structures that once served an important roll but now are mostly forgotten.

Interesting story and cool photos. Couldn't get to the end due to website design issues. Were these for horseback delivery or for airplanes?

Terrible, terrible UX in the form of a jittery delayed popover that fills the entire phone screen. If you are going to do this (and I can't stand the fact that it actually works on many people), make it so easy to dismiss and fast to load that I close it instead of instictively hitting back.

Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#27

Post by pilom »

beamatronic wrote: post #10

Could you infer the orbit of the satellite from the location of the X's?

If you had an image taken by the satellite and the time the image was taken, then yes. Google maps doesn't make it obvious but not all satellite images are taken from directly overhead. Most are off angle, so by calculating the distance on the film between known points on the earth, you could have a pretty good idea of the location of the satellite.when the picture was taken.

Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#28

Post by detaro »

beamatronic wrote: post #10

Could you infer the orbit of the satellite from the location of the X's?

I don't think so, since they'll cover all (or nearly all) of the earth the information that a satellite at an unknown time could see this spot doesn't tell you much.

Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#29

Post by lifeisstillgood »

strictnein wrote: post #15

One of the most interesting things about the Corona satellites was that they shot on film and that film was developed back on earth. So how'd they get that film back down from space? https://en.wikipedia.org/wiki/Corona_(satellite)#Recovery

And the mcguffin for the film Ice Station Zebra. Great film.

https://en.m.wikipedia.org/wiki/Ice_Station_Zebra

Re: Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?

#30

Post by tjohns »

dredmorbius wrote: post #18

The Corona project. A/K/A the KeyHole satellites. If my count is right, 135 satellite launches, though not all were successful. Fun fact: this was the early 1960s. CCD technology and IP transmission bitrates were a bit primitive[1], so the film cameras would eject capsules after they'd been shot, which would re-enter the atmosphere and be recovered, most through mid-air retrieval. The project was active from 1959 to…

Nitpicking here, but I think even most modern satellites don't use IP for their downlinks.

I suspect something like X.25 is used instead for digital data, if not something even more bespoke... and many satellites still send analog data.

For example, this is the protocol used for NOAA weather satellites (and actually was developed in the 60s): https://en.wikipedia.org/wiki/Automatic_picture_transmission

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