NASA’s tech demo streams first video from deep space via laser(jpl.nasa.gov)
jpl.nasa.gov
NASA’s tech demo streams first video from deep space via laser
https://www.jpl.nasa.gov/news/nasas-tech-demo-streams-first-video-from-deep-space-via-laser
55 comments
All else being equal, you could conceivably push a higher data rate on the forward link. The apertures are the same size, just the transmit and receive apertures are reversed, so geometric losses would be exactly the same. However, you can get a much more powerful laser on the ground since you don't have to worry about the power and thermal constraints you have with the transmitter on the spacecraft. This advantage will be pared down somewhat as the spacecraft won't have as sensitive a detector as the ground station (since it's harder to actively cool it for low dark count, for example). But on balance I expect you will come out ahead.
That said, on real world deep space missions, forward links are generally much slower than return links. This is because the slower you go, the better margin you have to close a link in adverse conditions (eg: mis-pointed spacecraft antenna for an RF link). Since you are completely screwed if you can't command the spacecraft, TT&C engineers will always go for a slower rate on the forward link for added Murphy insurance unless there's a pressing need to do otherwise.
That said, on real world deep space missions, forward links are generally much slower than return links. This is because the slower you go, the better margin you have to close a link in adverse conditions (eg: mis-pointed spacecraft antenna for an RF link). Since you are completely screwed if you can't command the spacecraft, TT&C engineers will always go for a slower rate on the forward link for added Murphy insurance unless there's a pressing need to do otherwise.
"cats have been dominating the airwaves from the beginning of broadcast video."
Maybe the Kzinti will think we are long lost relatives after receiving them.
(https://en.wikipedia.org/wiki/Kzin)
Maybe the Kzinti will think we are long lost relatives after receiving them.
(https://en.wikipedia.org/wiki/Kzin)
For more of "Taters the Space Cat" check out its Instagram https://www.instagram.com/taters_space_cat/
The laster travelled over 30 million km to be received by a dish of 20m^2 in area [1].
This makes me wonder: what fraction of the transmitted signal made it to that dish, i.e. how much does the beam disperse over that distance?
[1] https://en.wikipedia.org/wiki/Hale_Telescope
This makes me wonder: what fraction of the transmitted signal made it to that dish, i.e. how much does the beam disperse over that distance?
[1] https://en.wikipedia.org/wiki/Hale_Telescope
They also mention the video was sent on a loop, so I wonder how many loops it took to collect every frame.
If they received at 267 Mb/s that's probably faster than necessary for realtime decoding.
The laser spot can reach half the size of the continental united states. Though I'm not sure how large it is now because psyche is still relatively close to earth.
"The video signal took 101 seconds to reach Earth, sent at the system’s maximum bit rate of 267 megabits per second (Mbps)."
Based on some quick search, this is comparable to US median broadband download speed.
Based on some quick search, this is comparable to US median broadband download speed.
I think this also means that the the capacity of the empty space in 3.4GB. Someone has previously pointed out the interesting networking/caching(/storage?) implications for such long transmission time.
This idea is covered during the first part of one of my favorite Tom7 videos.
If this comment is the first you are hearing of Tom7... strap in and enjoy:
https://www.youtube.com/watch?v=JcJSW7Rprio
If this comment is the first you are hearing of Tom7... strap in and enjoy:
https://www.youtube.com/watch?v=JcJSW7Rprio
Indeed, you could use that empty space as delay line memory. That's some wicked latency, though.
Kind of amazing the article doesn't contain the word latency a single time.
It's good they're improving throughput/bandwidth but it doesn't help the big problem which is the latency.
It's good they're improving throughput/bandwidth but it doesn't help the big problem which is the latency.
There's a hard physical limit (speed of light) on latency that we can't do anything about. Higher bandwidth deep space communication gives us the ability to recover more science data from robotic missions, so it's worth working on.
I mean the latency problem is definitely not solvable, so why would they be trying to work on it?
They actually improved the data transfer latency considerably. An earlier version of the DSOC ground receiver was designed to dump data to a hard drive that would then be trucked over to Pasadena. Some joked that more bits might be lost on the I-210 freeway than between the asteroid belt and Earth.
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While not mentioned in the article, Spacelink (a spinoff from EOS) has a contract with the GSFC for tracking space objects for high bandwidth communication.
Interesting thing is EOS originally started in this field and later found there is a huge opportunity in military applications for it's stabilised tracking hardware/software such as remote weapons stations while the vehicle is moving.
https://eos-aus.com/nasa-awards-contract-to-spacelink/
Interesting thing is EOS originally started in this field and later found there is a huge opportunity in military applications for it's stabilised tracking hardware/software such as remote weapons stations while the vehicle is moving.
https://eos-aus.com/nasa-awards-contract-to-spacelink/
>"The video, featuring a cat named Taters, was sent back from nearly 19 million miles away by NASA’s laser communications demonstration, marking a historic milestone."
My thoughts:
As Neil Armstrong might say: "One small step for Man, one giant leap for...
Taters?!?!?!?!?
No, I'm just kidding about that of course! <g> :-) <g>
(https://en.wikiquote.org/wiki/Neil_Armstrong)
But on a more serious note, I think what NASA has accomplished here is a big step forward for future high bandwidth deep space communication...
Also, let's not forget that light, in this case, laser light, should travel at least a little bit faster than radio waves (the previous "old skool" method for deep space communication) -- at least if the classical physics EM theories hold true. (Side note: It would be interesting to know if laser light travels any faster, if even by the smallest amount, than regular light over extremely long distances -- but that's probably a future experiment for future experimenters...)
Anyway, it's a huge step forward for deep space communication!
Way to go NASA!!!
You guys rock! (As Felix Schlang might say!)
My thoughts:
As Neil Armstrong might say: "One small step for Man, one giant leap for...
Taters?!?!?!?!?
No, I'm just kidding about that of course! <g> :-) <g>
(https://en.wikiquote.org/wiki/Neil_Armstrong)
But on a more serious note, I think what NASA has accomplished here is a big step forward for future high bandwidth deep space communication...
Also, let's not forget that light, in this case, laser light, should travel at least a little bit faster than radio waves (the previous "old skool" method for deep space communication) -- at least if the classical physics EM theories hold true. (Side note: It would be interesting to know if laser light travels any faster, if even by the smallest amount, than regular light over extremely long distances -- but that's probably a future experiment for future experimenters...)
Anyway, it's a huge step forward for deep space communication!
Way to go NASA!!!
You guys rock! (As Felix Schlang might say!)
Trying to lure ALF with a dish. That's dedication.
It would be just be cool just to have a HD footage of satellite orbiting Mars or Venus.
A 267 Mb/s UHD cat video from 31 million kms.
What an age we live in.
What an age we live in.
How would one go about receiving and decoding such transmission at home? I would assume it's doable, no?
They used the Palomar observatory's Hale telescope to receive the signal. So it may be doable provided you have a 5.1 m aperture telescope at home
After traveling that distance, I would expect the video to be kind of... fuzzy.
Right, I'll show myself out...
Right, I'll show myself out...
I wonder how much error correction data was needed to be added
This is the channel coding and synchronization specification that is used on DSOC.
https://public.ccsds.org/Pubs/142x0b1.pdf
Yep I’m curious about what encoding was used. I doubt it was video optimized as realtime decoding likely wasn’t a goal.
Is this humanity's first attempt to test the Dark Forest Theory?
The opposite, if anything. The beam widths used for practical high bandwidth laser communication are extremely narrow. An alien civilization would have to (1) be in the exceedingly tiny fraction of the sky the beam covers, (2) have an unfathomably massive telescope with a correspondingly unfathomably tiny field of view capable of capturing enough photons to make a statistically significant detection, and (3) have that telescope pointed at the exact spot in their sky where the spacecraft is during an interval where it's transmitting. The odds are quite literally astronomical.
That's quite the bandwidth-delay product at 3.3GB.
How far we’ve come in less than half a century:
1977: NASA sends a carefully created record containing “sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form who may find them” into space (https://en.wikipedia.org/wiki/Voyager_Golden_Record)
2023: NASA sends a cat video into space.
1977: NASA sends a carefully created record containing “sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form who may find them” into space (https://en.wikipedia.org/wiki/Voyager_Golden_Record)
2023: NASA sends a cat video into space.
I was going to be pedantic about this (the laser downlink is from space, from Psyche-probe to Earth) but that got me wondering, how did they get the cat video on board? The article points out that it was loaded onto Psyche before launch.
Which means we're using rockets to send cat videos into (interplanetary) space... the logical evolution of the "station wagon full of magtapes" meme.
Which means we're using rockets to send cat videos into (interplanetary) space... the logical evolution of the "station wagon full of magtapes" meme.
Obviously they should have sent cat memes in 1977.
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As cute as Taters is, we already have Nyancat traveling through space so I'm a little disappointed Nyancat wasn't at least on the screen as "test information" lol
That, or they could have sent a clip from the movie The Cat From Outer Space
https://www.imdb.com/title/tt0077305/
Aw I loved that movie as a kid, yet another missed opportunity by NASA!
It's copyrighted and the copyright is enforced - https://en.wikipedia.org/wiki/Nyan_Cat#Lawsuit
10 hours of Nyan Cat for your pleasure. :)
https://youtu.be/jIQ6UV2onyI
https://youtu.be/jIQ6UV2onyI
Major missed opportunity
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imagine as a species being so powerful that you manipulate the fabric of reality to taint professional interstellar communication with an audiovisual feed of your presence
amazing
amazing
There's that old adage that Man used to worship cats, and that cats still think that's true.
I'm not positive the cats are wrong.
I mean, consider the Internet. ARPA invented the Internet. And, it's clear that the Internet's primary purpose is as an avenue for Cat worship. Just as the cats want.
ARPA became DARPA, DEFENSE Advanced Research Project Agency. DEFENSE! As in defending the homeland from external and existential threats. Normally they focus on things like lasers, and nuclear weapons, and preventing space rocks from slamming into the Earth and ending civilization. But, they still have their hooks into the Internet.
Promoting adoption, increasing capability. And, as posited before, the primary purpose of the Internet is facilitating cat worship. What does DARPA know that we don't?
MEANWHILE, we're having open Congressional panels about Aliens. No more cloak and dagger surrounding UFOs and and what not. That jig is up! Apparently, whatever secret pact the G-Men had with the Aliens is no longer in place. The cover is off, it's now just a matter of time.
But where are the hearings on Cats and their paws at the throats of power? We don't hear about that, do we? Cleary, this is far more dangerous than anything intra- or inter-galactic aliens can bring to the table.
So. I know, I know, I am but a whisper in the wind. An internet crackpot and troll. That, however, doesn't make the truth less clear.
At the same time, this message should be questioned. My cat, Georgie, is here and let me send it.
Why? I guess the cat being out of the bag is ok with them.
And I must cut this short, apparently there a tummy that needs to be rubbed.
I'm not positive the cats are wrong.
I mean, consider the Internet. ARPA invented the Internet. And, it's clear that the Internet's primary purpose is as an avenue for Cat worship. Just as the cats want.
ARPA became DARPA, DEFENSE Advanced Research Project Agency. DEFENSE! As in defending the homeland from external and existential threats. Normally they focus on things like lasers, and nuclear weapons, and preventing space rocks from slamming into the Earth and ending civilization. But, they still have their hooks into the Internet.
Promoting adoption, increasing capability. And, as posited before, the primary purpose of the Internet is facilitating cat worship. What does DARPA know that we don't?
MEANWHILE, we're having open Congressional panels about Aliens. No more cloak and dagger surrounding UFOs and and what not. That jig is up! Apparently, whatever secret pact the G-Men had with the Aliens is no longer in place. The cover is off, it's now just a matter of time.
But where are the hearings on Cats and their paws at the throats of power? We don't hear about that, do we? Cleary, this is far more dangerous than anything intra- or inter-galactic aliens can bring to the table.
So. I know, I know, I am but a whisper in the wind. An internet crackpot and troll. That, however, doesn't make the truth less clear.
At the same time, this message should be questioned. My cat, Georgie, is here and let me send it.
Why? I guess the cat being out of the bag is ok with them.
And I must cut this short, apparently there a tummy that needs to be rubbed.
Haven't we been inadvertently sending our terrestrial broadcasts into space for decades?
I remember a Futurama episode about aliens watching our TV programs.
I remember a Futurama episode about aliens watching our TV programs.
It's a common theme for Lrrr from the planet Omicron Persei 8 over several episodes
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I wonder, when cat will send from other star.
LIFE:: 5/9
Maybe Taters shouldn't chase after lasers with remaining lives.
Maybe Taters shouldn't chase after lasers with remaining lives.
So, cats have been dominating the airwaves from the beginning of broadcast video.
The article says the video was sent to earth at 267 Mbps.
As much as we are interested in watching interstellar feline adventures, I'd imagine future astronauts will be equally or more interested in watching videos of their favorite cats(or humans occasionally).
So, I'm curious to know the max speed at which we can transmit from earth to a spacecraft at similar distances.