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NASA Laser Communication System Sets Record with Transmissions to and from Moon
- 2close4comfort 13y agoThat is better than the connect at my house. I am moving there!
- Ellipsis753 13y agoTo NASA or the moon? I wouldn't think there's much good stuff to download from the moon but if you're on the moon then I'm sure there's plenty of cat videos you can download from Earth over that kind of connection.
- 2close4comfort 13y agoWith connectivity about 600x better than the average rural broadband connection. The direct application to purely to solve a problem it is great to see what we can do. That said it is kind of a bummer to see that once commerce gets involved that 1.5 dsl is good enough to claim your check from the FCC...but leaves a lot to be desired when trying to interact with the Modern world.
- milliams 13y agoThe latency would probably kill you though.
- throwaway9101 13y agoOr the cold.
- 2close4comfort 13y agoOr lack of atmosphere...but I digress. Plus I am sure that latency would be better than earth based sat transmissions
- kondro 13y agoYou could use lasers to fix this problem too.
- 2close4comfort 13y agoLAZERS RULE!
- erid 13y agoThe latency must be huge though.
- paulgerr 13y ago2.6 second round trip for light, so pretty huge ping times.
- nraynaud 13y agoThat's why I always found moon people to be lame at quake!
- Aardwolf 13y agoOne day technology will really have to do something about lightspeed to allow interplanetary quake!
- deletes 13y agoSolution for the lag will be a special category "bot play". The bot will not be programed but will behave like a black box, computer ai will record you every time you play in a local game and will slowly build the bot around. Then the bots will compete on a server, maybe separated by categories determined by previous recording time.
- rel 13y agoI worked at NASA (AMES) on a project to put small mobile robots on the moon. Our biggest goal was to create a tele-operated mode where from earth we could actively roam around the moon. The hardest part was that factoring in a 4 second delay from our commands to the network stacks to the rover on the moon, and then that video from the moon back to our computers and then creating good judgement. A 4 second delay seems insignificant but is in fact detrimental to intuitive controlling.
- gprasanth 13y agoUnless, our technology advances to always do stuff a couple of seconds in advance by knowing our intents.
- ck2 13y agoHow huge is a 1mm beam when it hits the moon (and visa-versa) ? I wonder if wolframalpha can tell me... Actually, I don't even know how to ask it the proper question. Can anyone make this formula work in wolfram? http://laserpointerforums.com/attachments/f51/17952-calculate-expansion-laser-beam-schematic_laser_beam.jpg http://laserpointerforums.com/attachments/f51/17952-calculat... update: I think I figured this out as ((λ * L) / d)* 2 (((630nm in meters)*(380000km in meters)) / (1mm in meters)) * 2 Which would be a nearly 500km wide for a 1mm beam on earth from a red laser at 630nm The shortest wavelength laser I can find online is experimental violet at 400nm which would make a 300km beam on the moon.
- colanderman 13y agoDepends on the focal length.
- femto 13y agoThe width of the beam is determined by diffraction, caused by the finite aperture of the laser: http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/cirapp.html http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/cirapp.htm...
- wyager 13y agoEven if the laser is extremely low divergence (maybe NASA is using some huge gas laser or something), atmospheric effects will still cause significant widening of the beam.
- deleted 13y ago[deleted]
- DanBC 13y agoHave you seen this "What If?" post by xkcd? http://what-if.xkcd.com/13/ http://what-if.xkcd.com/13/ It doesn't talk about the size of the beam as it hits the moon, but it's interesting noodling none-the-less.
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- Kabacaru 13y agoSo fine for torrenting crappy for gaming?
- VLM 13y agoI'm annoyed that gaming is defined solely as multi-player FPS twitch games. Astronauts / colonists into chess, go, poker, real role playing games, pretty much anything that happens in a casino, single player of any sort, wouldn't really notice.
- knowaveragejoe 13y agoBesides, the speeds mentioned here would be more than enough for multi-player twitch FPS too.
- jewel 13y agoA game like an FPS doesn't need much speed (they can work with modem-level bitrate). They instead depend on having low latency, or ping time. Since the moon is so far away, it takes a signal 1.3 seconds to travel to or from it.
- ceejayoz 13y agoOne speed interferes with multi-player twitch FPS here, and it's not the bandwidth - it's the speed of light. Try playing an FPS with 2+ seconds of lag and it'll be very, very unpleasant.
- bdegman 13y agoAlso once this is a real problem, hopefully there'll be enough people up there to fill up their own Battlefield servers with just moon players.
- aryastark 13y ago"damn lagkilling moon noobs!"
- peeters 13y agoThe article cites 622 Mbps down, 20 Mbps error-free up. Is the implication that the 622 Mbps down is before error correction? Either way, it's pretty incredible. Even if the 622 Mbps down isn't completely error free, but maybe 99%, you just need to use a video compression algorithm that is error tolerant.
- throwaway9101 13y agoOr FEC, and optionally reliable re-transmission. TCP won't work well due to the huge latencies involved.
- kordless 13y agoTCP can work decently with high latency, it just needs bigger buffers and to be tuned for the delay. FEC is awesome.
- deleted 13y ago[deleted]
- pilom 13y agoWhy is it easier to transmit from the moon to earth? Here we have more power and larger/better/faster/more tuned lasers than the space vehicle does. Seems like getting earth's transmit rate way up would be relatively easy while getting the vehicle's transmit rate up would be really really hard.
- zhouyunqing 13y agoI think it's the problems of the receiver. On the earth, we can build more elegant noise reduction systems, larger amplifiers and larger antennas.
- trentmb 13y agoMore, fancier equipment on Earth to receive and perform signal analysis? It's easier to get a new sensor online on Earth than on the moon.
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- jbarrec 13y agoThat's some lag!
- joshdance 13y agoThere is an xkcd that seems awfully appropriate here - http://what-if.xkcd.com/13/ http://what-if.xkcd.com/13/ - shooting lasers at the moon.
- s800 13y ago622mbps is interesting. Same as OC-12c... Something COTS?
- jpmattia 13y ago> Something COTS? Probably outside of the transmission/receiver. Choosing a conventional speed allows them to use plenty of off-the-shelf electronics (FEC chips, etc) and then focus on the transmission.
- dghughes 13y agoI remember reading on reddit or maybe it was here on HN that a laser is not a thing it's a method i.e. LASER, we use LASER not a laser.
- aggie 13y agoLanguage evolves. Unless you're writing a technical document it's usually best to go with what is commonly used and understood.
- freifunk_berlin 13y agoBackground information: http://www.spaceflight101.com/ladee-lunar-laser-communication-demonstration.html http://www.spaceflight101.com/ladee-lunar-laser-communicatio...
- devx 13y agoCouldn't we set-up a laser system to detect asteroids from farther away? Or would that be pretty inefficient?
- cdurr 13y agoShould be "laser" with the quotes. Also, LLCD isn't catchy - the project should be renamed to "The Allan Parsons Project".
- zaroth 13y agoWould it help at all to signal over RF to a low-orbit relay, and then go optical just between two points in space? Much less atmosphere to contend with...