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Decades-Old Mystery Put to Rest: Why Are There X's in the Desert?
- SCHiM 10y agotl/dr: U.S. Military spy satellite camera calibration.
- wyldfire 10y agoYes, indeed but read it anyways! ;) It's not too long IMO and the human element of the story is lost in this summary.
- dsjoerg 10y agoToo long for me! Just here to waste a minute and the TLDR does me a service.
- Animats 10y agoRight. Since each "mysterious" X was equipped with a "US Army Corps of Engineers" brass plate, it was kind of obvious they were calibration targets for something military. The article says "focusing", but they were probably used to get more precise orbital elements for satellites. This was pre-GPS, and calibration across geography on a planetary scale was tough.
- astrodust 10y agoLeft open to rampant speculation it could be test targets for bombing.
- planteen 10y ago> The article says "focusing", but they were probably used to get more precise orbital elements for satellites. This was pre-GPS, and calibration across geography on a planetary scale was tough. My guess is that they served a function for calibrating ground control points rather than orbital elements. Even today, NORAD publishes orbital elements (TLEs) for spacecraft deduced by radar (and also optical means). I think other radio ranging techniques were also used before GPS. Trying to point at Earth-fixed point with only an inertial attitude (without a position/velocity) seems really tough. Today, lots of CubeSats don't have GPS, so they eagerly await getting TLEs from NORAD. It seems like this Twitter is always the first with new data: https://twitter.com/TSKelso https://twitter.com/TSKelso
- dukoid 10y agoDid anybody find one on Google Maps in Satellite mode?
- tugs 10y agoI found two: 32.807001, -111.722184 and 32.791790, -111.705250 I'd like to find more to see the 'grid' mentioned in the article.
- brianwawok 10y agoHah the first one is next door to a gun range.
- sago 10y ago32.807147, -111.688916
- sago 10y agohttps://www.google.com/maps/d/u/0/viewer?mid=1IudNrZA1xnpWjKlscWlSakQHDKo https://www.google.com/maps/d/u/0/viewer?mid=1IudNrZA1xnpWjK...
- snovv_crash 10y agoThe description there implies that the other crosses no longer remain, but I was able to find the first 3 I looked for just by looking for midpoints between other markers on the grid.
- sago 10y agoYes, it definitely doesn't have them all. I've found more too. Perhaps the map maker got bored.
- ZeKK14 10y agoI added a few more : https://drive.google.com/open?id=15z8VmPCAGRXwaQ9yxkAGfr2cugo&usp=sharing https://drive.google.com/open?id=15z8VmPCAGRXwaQ9yxkAGfr2cug...
- djsumdog 10y ago> "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 to the deaths of countless civilians in the former USSR nations.
- fizzbatter 10y agoI 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?
- mslev 10y agoI 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/transcontinental-air-mail-route-maphead-ken-jennings http://www.cntraveler.com/stories/2013-06-17/transcontinenta...
- hansjorg 10y agoIt's not mentioned in the article, but I guess this means that compass navigation wasn't possible at the time?
- mikestew 10y agoNot 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.
- danielvf 10y agoEven perfect charts would have been useless - the early airmail mail flew at night, in bad weather, with single pilots in open cockpits.
- danielvf 10y agoThey did have compasses, but those do not give you your position. So if you've been flying for four hours at night, with a thirty mph wind, you could be 120 miles away from where you planned on being. You need some way of getting an absolute position, which these provided.
- astrodust 10y agoWindspeed is not unlike ocean currents, but since the speeds involved are a lot higher than in a boat errors in estimation accumulate way more quickly.
- beamatronic 10y agoCould you infer the orbit of the satellite from the location of the X's?
- pilom 10y agoIf 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.
- detaro 10y agoI 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.
- LoSboccacc 10y agono because you get just one point in time and to compute an orbit you'd need three (or the apogeo/perigeo + another)
- okket 10y agoThe in the story linked movie about the Corona Project is an amazing document of history. https://archive.org/details/gov.archives.arc.1678526 https://archive.org/details/gov.archives.arc.1678526
- c0rtex 10y agoSame thing on YT: https://www.youtube.com/watch?v=k3bzHk_6yHM https://www.youtube.com/watch?v=k3bzHk_6yHM For those who like to watch at 2x.
- strictnein 10y agoOne 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 https://en.wikipedia.org/wiki/Corona_(satellite)#Recovery
- fizzbatter 10y agoAnswered here: https://news.ycombinator.com/item?id=12695808 https://news.ycombinator.com/item?id=12695808
- ptaipale 10y agoAnother question of course is that since it was impossible to load the cameras with new film, how much film did they carry when deployed? After using it all the camera was useless. A modern digital camera would have been really valuable for these purposes. BTW were those Corona satellites guidable, or did they just fly wherever they flew and operators could ask them to photograph what was under? A useful way to decommission a satellite that is about to run out of its film storage would have been to guide it to a trajectory where it can take more accurate pictures from a lower position -- because once the satellite goes on such a trajectory, it will soon come down completely. But if you could use the last bit of film that way, and eject it for retrieval, then the dying of the satellite would at least have been utilized.
- creshal 10y ago> Another question of course is that since it was impossible to load the cameras with new film, how much film did they carry when deployed? After using it all the camera was useless. That's why both the US and Russians experimented with military space stations (US MOL, Soviet Almaz), so they could both resupply the cameras with more film, and in emergencies develop it directly in space and radio down scans of them. However, both eventually figured out how do automate the latter and eventually developed fully digital cameras, rendering manned surveillance stations obsolete. The US never launched any, and the Soviet program was cancelled after three stations (that were masked as Salyuts). > BTW were those Corona satellites guidable, or did they just fly wherever they flew and operators could ask them to photograph what was under? Satellite orbits are largely fixed – changing your orbital plane is the single most expensive manoeuvre you can do, and too expensive in practice. (Even if we wanted to, we couldn't tilt the ISS' orbit by more than a degree or two, and if we did, Soyuz rockets couldn't reach it any more.) That's why we instead just launch a whole lot of satellites that focus on different areas. > A useful way to decommission a satellite that is about to run out of its film storage would have been to guide it to a trajectory where it can take more accurate pictures from a lower position Even just lowering your orbit is expensive, fuel-wise, but the more important problem: The lower you go, the faster you are. This means lower exposure times and less image quality, not more. Additionally, as far as I can tell, the film buckets were really dumb and used solid boosters hand-tuned to their original orbit. Launching them from a different trajectory would likely make them burn up during re-entry.
- dredmorbius 10y agoThe 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 1972. https://en.m.wikipedia.org/wiki/Mid-air_retrieval https://en.m.wikipedia.org/wiki/Mid-air_retrieval https://en.m.wikipedia.org/wiki/Corona_(satellite) https://en.m.wikipedia.org/wiki/Corona_(satellite) Video of recovery: http://petapixel.com/2014/08/31/us-spy-satellites-used-drop-photos-film-buckets-space-airplanes-catch-mid-air/ http://petapixel.com/2014/08/31/us-spy-satellites-used-drop-... ______________________________ Notes: 1. Well, technically they didn't exist.
- tjohns 10y agoNitpicking 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 https://en.wikipedia.org/wiki/Automatic_picture_transmission
- dredmorbius 10y agoThat was a flip bit of stage-setting. I know little about space data transmission (though I vaguely recall some good discussion around the time of the New Horizons Pluto contact), but yes, it's been a mix of analog transmissions (initially) and digital, of various descriptions. I believe there is an IP-based transmission support for the ISS, though I wouldn't swear to that. One of the zaniest image transmission protocols was for the early Soviet lunar missions, Luna 3. Again, film cameras, an in-spacecraft photo processing lab, and a TV camera to read off the film image and transmit it back to Earth. The image quality wasn't much, but it was the first imagery of the Lunar farside ever received. https://en.m.wikipedia.org/wiki/Luna_3 https://en.m.wikipedia.org/wiki/Luna_3 A few years back there was a story of the National Geographic lunar map timed to coincide (well, a month late) with the December, 1968, Apollo 8 mission, the first manned flight around the Moon (though without a landing). This gave us the famous Earthrise photograph, and the Christmas Day broadcast from Apollo. The story of the map, and how rapidly the Lunar far side went from terra incognito (well, luna incognito) to mapped in detail was pretty staggering. I had that map as a kid, and just figured "we knew all that". Sometimes it takes growing up to see things with childlike wonder.... The story: http://kelsocartography.com/blog/?p=1481 http://kelsocartography.com/blog/?p=1481 http://kelsocartography.com/blog/?p=1588 http://kelsocartography.com/blog/?p=1588 (Pretty sure that's made HN at some point.)
- ythl 10y agoTL;DR - They were used by the US Army during the Cold War to calibrate spy satellite cameras.
- LyalinDotCom 10y agolol you beat me to it on posting the summary :), but good story.
- zerooneinfinity 10y agoCan someone explain to my dumbass how they helped calibrate the photos or satellites?
- mabbo 10y agoOkay, I just spent 20 minutes trying to figure that out and I'm still not very far. These were film cameras, so the computer on board can't look through the camera and see if the objects are in focus, can they?
- 13of40 10y agoThey took a whole series of images at different focuses, then dropped it to earth and people radioed back the most in-focus setting....is how I'd do it.
- idlewords 10y agoHeh, "computer on board". Waving my cane at you!
- HeyLaughingBoy 10y agoWell, I'm going to assume there was no actual "computer" on board... However, a sharply focused image has more high-frequency components than a poorly focused one, so some sort of frequency discriminator (a technology from the 1920's IIRC) could possibly suffice to check and adjust focus. Remember that we've had sophisticated servomechanisms since WW2 so the feedback theory to do this was already well known. But that's just a guess...
- astrodust 10y agoThey're spaced out over miles, so presumably they'd take a wide shot of a bunch of them and check that the focus on one side of the frame to the other would be consistent. Think of it as an eye chart for satellites.
- vizzah 10y agoThey could have embedded LOVE instead of X's and it wouldn't have created any mystery and unneeded attention, as everyone would know it was hipsters.. no, I mean hippies.. =D
- grkvlt 10y agoAlso interesting are the resolution targets, using sets of black and white bars at varying widths in both X any X orientation, to determine the spatial resolution i.e. how high frequency a component could still be imaged separately as lines, similar to TV test cards. These are discussed in various blogs [1][2] with some amazing picures. I think these were for both satellite imaging and spy-plane (U2 and SR-71 plus less exotic surveillance systems) and not just the USA. This article [3] shows some satellite test targets in the Gobi desert, presumable for Chinese (PRC) spy satellites, and also has a cool picture of the world's largest compass rose, at Edwards dry lake bed, as well as explaining the crosses from the original article, and talking about radar altimeter targets (another dry-lake bed) that are mapped to centimetre accuracy in altitude for calibrating GPS and other systems. I find it a really interesting area of industrial/scientific archaeology, with some fascinating stories. [1] http://www.clui.org/newsletter/winter-2013/photo-calibration-targets http://www.clui.org/newsletter/winter-2013/photo-calibration... [2] http://www.bldgblog.com/2013/02/optical-calibration-targets/ http://www.bldgblog.com/2013/02/optical-calibration-targets/ [3] http://www.atlasobscura.com/articles/landscapes-made-for-satellite-eyes-calibration-targets-resolution-tests-and-giant-desert-compasses http://www.atlasobscura.com/articles/landscapes-made-for-sat...
- LoSboccacc 10y ago"Those X where used to calibrate spy satellites camera" #stopclickbait
- CoryOndrejka 10y agoMy dad was project photogrammetrist on Corona when he worked at Itek in the 60s. Lots of stories around focus and aiming challenges, since Corona was used to build maps of inaccessible regions of the world (e.g. Soviet Union ICMB sites). Focus targets gave high contrast, known images to detect what kind of focus problems were being encountered -- ranging from image smear from forward motion compensation failing or stretching the film; film sticking, stretching and/or lifting off of the focal plane; star camera inaccuracies; thermal distortion of camera, spacecraft, star camera, or film; etc. A few good books on Corona (https://www.cia.gov/library/publications/intelligence-history/corona-between-the-sun-and-the-earth https://www.cia.gov/library/publications/intelligence-histor...) and Itek (https://books.google.com/books/about/Spy_Capitalism.html https://books.google.com/books/about/Spy_Capitalism.html) out there. Same teams worked on subsequent KH projects (Gambit, Hexagon/Big Bird/BMF), as well as Apollo and Viking camera systems.
- 127001brewer 10y agoInteresting: I've submitted this story over a day ago (https://news.ycombinator.com/item?id=12684118 https://news.ycombinator.com/item?id=12684118) with a clean URL, yet this submission got noticed? Yes, good luck and good timing, but still - ha!
- initram 10y agoAnyone know what's nearby there at about (32.92669, -111.922201)[0]? It looks like some sort of strip mine a few hundred feet to the north, so I assume it's related, but was just curious what it is. It looks like a painting! [0] http://maps.apple.com/maps?ll=32.926699,-111.822201&spn=0.006796,0.014104&t=k http://maps.apple.com/maps?ll=32.926699,-111.822201&spn=0.00...
- thwarted 10y agoLooks like some kind of debris pile, perhaps from the mine. The corners are angled like it's building up to an eventual truncated pyramid shape, and the one in the upper left looks higher, and "finished" compared to the other three. There's a similar pile that isn't laid out as a square just south of the mine, you can see the multiple layers getting smaller as it gets higher.
- e2021 10y agoLooks like a tailings dam to me, containing waste materials from the mine after processing. The solution has partially evaporated leaving a salt residue. At least thats what it looks like to me. I don't think its a raised pyramid like the other reply says, pretty sure it is a hole. If you do a google image search for 'tailings dam' you see some things that look pretty similar...
- fit2rule 10y agoFascinating discovery, it truly does look like a bit of modern art .. I sit here considering making a desktop wallpaper of it, at least ..
- helb 10y agoAs e2021 said, these are some kind of tailing dams to treat remaining water from mining. Google even has streetview photos from the nearby road, resolution is just enough to read "[something] wastewater evaporation ponds" on the fence sign: https://goo.gl/maps/WZKbdPxs5sS2 https://goo.gl/maps/WZKbdPxs5sS2 The mine itself looks cool, too: https://www.google.cz/search?q=Casa+Grande+Copper+Mine&safe=off&tbm=isch https://www.google.cz/search?q=Casa+Grande+Copper+Mine&safe=...
- 10y ago
- kahrkunne 10y agoI bet the Corona thing is just a cover story for pirate treasure
- sago 10y agoHere's a map of them. Corrections and additions welcome. https://drive.google.com/open?id=1bebA9E6kTb3G9g5GEeezYPzvwHo https://drive.google.com/open?id=1bebA9E6kTb3G9g5GEeezYPzvwH... Based on the map from wikipedia, which had 84 locations, this has 120.
- jlebrech 10y agomy guess was a marker for mexican drug cartels to drop packages.