[HN Gopher] The Parachute Message
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       The Parachute Message
        
       Author : sunraa
       Score  : 57 points
       Date   : 2021-02-24 20:01 UTC (2 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | mzs wrote:
       | official word: https://www.jpl.nasa.gov/images/mars-decoder-ring
        
       | 725686 wrote:
       | I wonder how much more expensive was it to create the parachute
       | with the code.
        
         | bentcorner wrote:
         | Probably not a lot. I believe they needed to create a pattern
         | on the parachute anyway for tracking orientation and inflation.
        
         | [deleted]
        
       | revicon wrote:
       | Here's where the coordinates on the outer rim point to (For the
       | lazy) https://goo.gl/maps/MCqYxngeQLJRMNeK7
        
         | forgotmypw17 wrote:
         | DARE MIGHTY THINGS
        
         | LeifCarrotson wrote:
         | Interestingly, their hands were somewhat tied when it came to
         | coordinate system precision [1] because they had eight 7-bit
         | words to encode with data.
         | 
         | They couldn't say "34.20 N 118.17 W", which would indicate
         | they're talking about the whole campus and industrial park it's
         | in, because that's only 6 words.
         | 
         | Instead, by defining it to a precision of one arcsecond, they
         | imply that JPL is located within the 30-by-25-meter rectangle
         | [2] between 34deg11'58.5"N 118deg10'31.5"W and 34deg11'57.5"N
         | 118deg10'30.5"W, which is basically a turnaround and associated
         | parking lot island.
         | 
         | [1] Relevant XKCD: https://xkcd.com/2170/ [2] Rectangular [3]
         | because the circle around the earth at higher latitudes is
         | smaller than the circle at the equator. [3] OK, approximately
         | rectangular. It's rectangular on a Mercator projection map!
        
       | lscotte wrote:
       | JPL has a history of hiding messages like this. One of the rovers
       | leaves tracks that spell "JPL" in morse code. I think it's all
       | kind of fun.
        
       | nihil75 wrote:
       | A little disappointing actually! I thought the pattern was a
       | clever way to capture the status of the parachute in the event of
       | failure, so if all they got was a garbled low-res image before
       | the lander crashed to the surface they could deduce which section
       | failed. Alas, it was just an easter-egg..
        
         | noizejoy wrote:
         | > ... just an easter-egg ..
         | 
         | Not true, according to OP:
         | 
         | > Allen Chen revealed that there was a code hidden in the
         | parachute, as well as the markings being useful for camera
         | alignment.
        
       | KineticLensman wrote:
       | The British company that made the parachute's fabric has a great
       | little piece about it here [0]. In 15 years they went from a demo
       | at a symposium in the US to a canopy that could achieve a 98%
       | reduction in the re-entry speed of a massive payload.
       | 
       | [0] https://www.heathcoat.co.uk/perseverance-landing/
        
       | abalaji wrote:
       | I was one of the people who went viral on twitter and was
       | interviewed by the NYT for posting the solution. [1, 2] It was
       | really neat to see people all over the world come together to
       | solve this puzzles in <6 hours. [3]
       | 
       | [1]
       | https://twitter.com/adithya_balaji/status/136402008259946087...
       | 
       | [2] https://www.nytimes.com/2021/02/24/science/nasa-mars-
       | parachu...
       | 
       | [3]
       | https://twitter.com/steltzner/status/1364076615932645379?s=2...
        
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       (page generated 2021-02-24 23:00 UTC)