121–130 of 197 posts
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The data rate from the surface of titan is abysmal. Even with a relay, we won't get much video, but man, I hope we get some.
Don't get your hopes down! It's still very possible that we'll get some good, if not real-time, video out of this!
A flying drone is a really solid idea for a Titan lander for a couple reasons: * The surface atmosphere density is higher than Earth's (1.5 atm) * Gravitational force is much lower (0.15g) * We don't know a lot about the surface composition or topography, so wheels and motors represent a challenge * Visibility may be poor, making visual navigation tricky (though that's also a problem for a flying vehicle I suppose) I…
How does one test on earth, a drone for a different atmospheric and gravitational environment? Some great drone simulation techniques are going to come out of this project.
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Why is bandwidth so scare still? Satellites in geosynchronous orbit on earth can do terabit/sec of total capacity now. Obviously latency is going to be extremely high, but I can't really understand why data rates are still so low?
Inverse square law. For the same transmit power, your received signal strength diminishes with the square of the distance That received signal strength is what determines channel capacity (C) which is the upper limit on the bit rate you can get. see Friis and Shannon's channel capacity [0] https://en.wikipedia.org/wiki/Friis_transmission_equation [1] https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...
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Don't get your hopes down! It's still very possible that we'll get some good, if not real-time, video out of this!
There will be at least an hour delay. Saturn is pretty far
Now figuring out which 10 seconds to select and send to earth... that'll be interesting. An on-board cache of x GB data storage, with key frames taken every 30 minutes, would probably be able to select some pretty compelling 10 second segments.
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The data rate from the surface of titan is abysmal. Even with a relay, we won't get much video, but man, I hope we get some.
From a scientific standpoint, there's really no value in downlinking video as opposed to still images. It costs several multiples worth of scarce downlink bandwidth, for a tiny gain in what there is to see of the same rocks at slightly different angles. Same reason we didn't have New Horizons at Pluto or the various Mars rovers do any video.
[0]https://www.jhuapl.edu/techdigest/TD/td3403/34_03-Lorenz.pdf [1]https://www.news.gatech.edu/2017/03/27/electric-sands-titan
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I find it kind of funny that you think AWS will still be around in a hundred years.
This paper company was founded 771 AD: https://www.shinise.ne.jp/j_kyoto/voices/vol/48/48-d.html It's not even the longest-lived company in the world. This construction company was founded in 578 AD and continuously operated until 2006 when it was bought by a larger company: https://en.wikipedia.org/wiki/Kong%C5%8D_Gumi 100 years ago was only 1919 -- here are some random companies from 1919 that I found on Wikipedia…
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No. >> The Pentagon is aware of a Russian test of a nuclear-powered cruise missile but the system is still under development and had crashed in the Arctic in 2017.[17][18][19] A RAND Corporation researcher specializing in Russia said "My guess is they're not bluffing, that they've flight-tested this thing. But that's incredible." https://en.wikipedia.org/wiki/Nuclear-powered_aircraft#Russi... https://en.wikipedia.org…
Why bother? Rocket fuel is cheaper than nuclear fuel and rocket missiles can already hit anywhere.
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In addition to lack of solar energy, I wonder if nuclear power source is necessary to keep batteries or other electronics warm enough to function properly. Conversely, on Titan, we won't need to worry about heat sinks as everything is kept at ~94K in a bath of liquid and frozen methane. Perhaps in a few hundred years AWS's most popular region for intensive compute will be under Titan's methane sea. High spin up cost,…
Hah, I was always intrigued by the idea of placing solar cells on the bright side of Mercury and servers on the dark side. I wonder what other good options might exist in the solar system.
Yes, you need equipment that can swap being hot and cold, but it's a lot easier to get to :)
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Space travel just makes it utterly clear there is on such thing as real time. Computing is constantly running up against the speed of light.
In a sense tho, at-the-speed-of-light is real time, as it's the maximum speed of anything.
A flying drone is a really solid idea for a Titan lander for a couple reasons: * The surface atmosphere density is higher than Earth's (1.5 atm) * Gravitational force is much lower (0.15g) * We don't know a lot about the surface composition or topography, so wheels and motors represent a challenge * Visibility may be poor, making visual navigation tricky (though that's also a problem for a flying vehicle I suppose) I…
Will this be the first-ever instance of nuclear-powered flight?
https://www.space.com/13709-plutonium-shortage-nasa-planetar...
Unfortunately, there is a shortage of plutonium-238 to run these RTGs (see above story). I guess that will get resolved somehow.
The current Mars Curiosity rover is powered by an RTG. Since this is the first flying (post-landing of course) probe I suppose it will be the first nuclear powered flight of a planetary probe.