this post was submitted on 19 Dec 2023
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[–] [email protected] 47 points 11 months ago (4 children)

Bit annoying that they're more specific about latency than bandwidth. The laser had lower latency than broadband, but I want to know if the laser had enough bandwidth to stream the video.

[–] [email protected] 38 points 11 months ago (1 children)

This latest milestone comes after “first light” was achieved on Nov. 14. Since then, the system has demonstrated faster data downlink speeds and increased pointing accuracy during its weekly checkouts. On the night of Dec. 4, the project demonstrated downlink bit rates of 62.5 Mbps, 100 Mbps, and 267 Mbps, which is comparable to broadband internet download speeds. The team was able to download a total of 1.3 terabits of data during that time. As a comparison, NASA’s Magellan mission to Venus downlinked 1.2 terabits during its entire mission from 1990 to 1994.

https://www.nasa.gov/directorates/stmd/tech-demo-missions-program/deep-space-optical-communications-dsoc/nasas-tech-demo-streams-first-video-from-deep-space-via-laser/

[–] [email protected] 7 points 11 months ago (2 children)

Honestly the 1.2 TB I'm the early 90s is an insanely impressive figure to me. I mean in that era a gigabyte seemed like an obscene amount of data, the interat ran at less than 56 kbps, and I don't think I had a 1GB drive in my hime PC until almost the turn of the millennium. Sending and storing that much from venus is a huge accomplishment.

[–] [email protected] 12 points 11 months ago* (last edited 11 months ago)

1.2 Tb* ~ 150GB

Still impressive though

[–] [email protected] 4 points 11 months ago* (last edited 11 months ago)

They probably stored it on tape which was slow but could hold an impressive amount of data.

I remember my first multi gig hard drive. I was blown away that I could fully install Diablo 2, Fallout 2, and a cracked version of 3d Studio Max at the same time. No more changing disks!

[–] [email protected] 21 points 11 months ago* (last edited 11 months ago) (1 children)

Lower latency than broadband...?

If you're getting >100s ping times you might want to have them come out to check your lines.

[–] [email protected] 26 points 11 months ago (2 children)

Something tells me you're not getting sub 100ms latency with broadband over 19 million miles

[–] [email protected] 11 points 11 months ago (1 children)

They're new high tech lasers that go faster than the speed of light!

[–] [email protected] 9 points 11 months ago (1 children)

Actually, most latency issues at that scale are due to the relays themselves. Earth diameter is only 42 light-ms

[–] [email protected] 2 points 11 months ago

19 million miles is 102 light seconds.

[–] [email protected] 1 points 11 months ago

I mean, if their point was that a straight-shot laser had lower point-to-point latency than a system with a bunch of non-direct links, intermediate switches, routers, mix of copper and fiber, etc... Well, no kidding.

Didn't say anything about 100ms though. I was guessing maybe they read 100ms though. Still not sure what the point was.

[–] [email protected] 19 points 11 months ago

"The video was then downloaded and each frame was sent to NASA's Jet Propulsion Laboratory in Southern California, where it was played in real time. "

It sounds like it. Laser comm can have some insanely high data rates due to the high frequency of the radiation.

[–] [email protected] 7 points 11 months ago (1 children)

if you want more bandwidth you can just use more lasers

[–] [email protected] 7 points 11 months ago

More lasers!!!!