NASA’s tech demo streams first video from deep space via laser

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.

"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)

They also mention the video was sent on a loop, so I wonder how many loops it took to collect every frame.

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.

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.

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.

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

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.

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.

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.

Obviously they should have sent cat memes in 1977.

That, or they could have sent a clip from the movie The Cat From Outer Space https://www.imdb.com/title/tt0077305/

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

Major missed opportunity

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.

Haven't we been inadvertently sending our terrestrial broadcasts into space for decades?

I remember a Futurama episode about aliens watching our TV programs.