Arthur T Knackerbracket has processed the following story:
NASA hopes to launch a near-infrared laser transceiver to test a system that could one day be used to communicate with astronauts on Mars.
The Deep Space Optical Communications (DSOC) experiment will head off into the void with Psyche, an asteroid-chasing probe that is scheduled to blast off on October 5. While they journey toward 16 Psyche, a metal-rich asteroid, the DSOC system will spend two years attempting to communicate via laser with two ground stations in Southern California.
NASA believes DSOC's near-infrared lasers can trounce the data transmission speeds achieved using radios.
"DSOC was designed to demonstrate 10 to 100 times the data-return capacity of state-of-the-art radio systems used in space today," enthused Abi Biswas, DSOC's project technologist working at NASA's Jet Propulsion Laboratory. "High-bandwidth laser communications for near-Earth orbit and for Moon-orbiting satellites have been proven, but deep space presents new challenges."
NASA's most recent Mars rover, Perseverance, can communicate with orbiters at two megabits per second. The Mars Reconnaissance Orbiter can chat to Earth at between 0.5 to 4 megabits per second.
Improving those speeds by a factor of between 10 and 100 with lasers therefore has an obvious benefit – even if the pesky limit that is the speed of light means it won't allow synchronous comms with the Red Planet.
[...] "Every component of DSOC exhibits new technology – from the high-power uplink lasers to the pointing system on the transceiver's telescope and down to the exquisitely sensitive detectors that can count the single photons as they arrive," explained Bill Klipstein, the DSOC project manager at JPL. "The team even needed to develop new signal-processing techniques to squeeze information out of such weak signals transmitted over vast distances."
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CubeSat Set to Demonstrate NASA's Fastest Laser Link from Space:
NASA's Pathfinder Technology Demonstrator 3 (PTD-3) mission, carrying the TeraByte InfraRed Delivery (TBIRD) system, will debut on May 25 [for a 6-month experiment] as part of SpaceX's Transporter-5 rideshare launch. TBIRD will showcase the high-data-rate capabilities of laser communications from a CubeSat in low-Earth orbit. At 200 gigabits per second (Gbps), TBIRD will downlink data at the highest optical rate ever achieved by NASA.
NASA primarily uses radio frequency to communicate with spacecraft, but with sights set on human exploration of the Moon and Mars and the development of enhanced scientific instruments, NASA needs more efficient communications systems to transmit significant amounts of data. With more data, researchers can make profound discoveries. Laser communications substantially increases data transport capabilities, offering higher data rates and more information packed into a single transmission.
Extending Earth's Internet to Mars With Orbital Data Servers:
You've done it. After years of effort and training, sacrifice, and pain, you become an astronaut and have finally set foot on Mars. Time to post your triumph on TikTok for that sweet social media cred. If only you can get a signal.
While that might seem like a silly scenario, the need for internet connectivity on Mars is real. It's not just a matter of allowing astronauts to doomscroll and post on Reddit. Landing humans on Mars will require a tremendous amount of data transfer with Earth, which is not easy. So how can we create an information network on Mars that is robust enough for both logistic and personal needs? A paper posted on the arxiv proposes an idea.
[...] One of these ideas, as the paper outlines, is edge computing. Although you probably don't notice it, edge computing is why you can watch streaming services like Netflix and Disney+. It takes a tremendous amount of bandwidth to stream television and movies, so streaming services distribute their servers to get you better speeds. [...]
This latest work looks at what it would take to have an edge computing network around Mars. The key is not only to have data locally accessible, but also to have a certain level of redundancy. So they propose building a constellation of satellites around Mars. Their system would have 9 satellites each in 9 orbital planes, for a total of 81 satellites. As with many constellations, the satellites would communicate with each other to have redundant backups of data. This means various landing sites on Mars would be able to communicate with 2 or 3 satellites at any given time. For extended missions, ground-based servers could be used for even faster data retrieval.
Building such a system would not be cheap, so the authors propose building the constellation in stages. As exploratory missions to Mars lay the groundwork for crewed landing, a few constellation satellites could go along for the ride. By the time long-term stations are being built, the constellation could already be in place.
Journal Reference:
Pfandzelter, Tobias, and David Bermbach. "Can Orbital Servers Provide Mars-Wide Edge Computing?" arXiv preprint arXiv:2306.09756 (2023).
(Score: 2, Interesting) by anubi on Friday August 11 2023, @07:25PM (7 children)
Both ends are in space, in stable orbits, around their respective planet, both planets in stable orbits around the same sun.
Lasers are incredibly well collimated, the limited laser light energy we have to encode the data on is confined to a really tight beam.
Now it gets fun. The Earth side is a liason between Earth and Mars, which will have significant, but slowly changing angular vector to Earth, as well as a significant acceleration ( but still in the same inertial frame of reference...neither end experiences any inertial acceleration...all in the same spacetime curvature ), yet I would expect considerable slew of the carrier frequencies to the changing relayltive velocities involved. Nothing really new there either. The voyagers did the same thing as we used the gas giants to sling them clear of our solar system, making them wanderers of interstellar space until they fall into something else's gravity well
Of course, the Mars end will perform similar liason between Mars Planet, Mars Orbit, and Earth link.
Three separate communication channel vectors.
At least three, maybe more, constantly changing antenna pointings.
And problems with bearings in space. Maybe magnetic? Do magnets attract solar wind particles? Communications itself could be done via short range wireless network techniques. Keeping power connected is another challenge.
Maybe the satellites be grouped in clusters, magnetically positioned, to allow each antenna to be pointed toward its partner across the void?
Some young person is going to get a really interesting design challenge out of this.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 3, Interesting) by inertnet on Friday August 11 2023, @07:40PM (4 children)
To get maximum coverage, you still need to solve the "line of sight" problem called opposition. Maybe with a relay station at a Lagrange point.
(Score: 3, Interesting) by mhajicek on Friday August 11 2023, @10:30PM (3 children)
Put a few satellites in Mars orbit and you've got that covered.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 3, Insightful) by inertnet on Saturday August 12 2023, @12:22PM (2 children)
Their orbits would have to be wider than the sun, for times when the sun is between Earth and Mars, so at least 700.000 km.
(Score: 3, Insightful) by mhajicek on Saturday August 12 2023, @03:47PM (1 child)
No, for that rare case, you just need one more relay sat in another location.
The spacelike surfaces of time foliations can have a cusp at the surface of discontinuity. - P. Hajicek
(Score: 2) by inertnet on Saturday August 12 2023, @08:42PM
I'll quote myself:
(Score: 5, Informative) by JoeMerchant on Friday August 11 2023, @07:51PM (1 child)
>Lasers are incredibly well collimated
These lasers have to be. Most "lasers" you encounter, like diodes in DVD readers, are incredibly poorly collimated.
Most methods of collimation also reduce the intensity of the resultant focused beam. I played with collimating lenses on a gas tube laser (spot size on exit from the tube maybe 3mm) shining on a big building approximately 1000 meters away. Without collimation, the laser spot was huge and diffuse, hard to see - maybe 3 meters high. With the lenses, the spot got much smaller, maybe 30cm diameter, but it was not 100x brighter - maybe 10x at best - the overall energy in the collimated spot was about 10% of what was in the bigger more diffuse spot.
The distance Earth-Mars is 50,000,000 to 400,000,000 km. That 30cm spot would be ~40,000 km across by the time it reached Mars. Yes, they have better collimators, but at some point you hit diminishing returns where you may as well let the far-end spot be a few km across to make the targeting easier.
🌻🌻🌻 [google.com]
(Score: 3, Interesting) by corey on Friday August 11 2023, @11:57PM
Interesting. I was reading about the pros and cons of THz RF vs mmEave vs FSOC (Freesoace optical communications) in the latest IEEE AESS magazine. The THz comms has distinct advantages to both, from manufacturability to the electronics and even comms speed. I can’t remember the details and I’m using my phone so typing details isn’t fun.
But I think it’s worth NASA looking at quantum entanglement for this application. I know the Chinese have a sat flying which they are researching this with. Americans are doing the same.
(Score: 1) by Runaway1956 on Friday August 11 2023, @07:32PM (3 children)
They are already communicating at light speed. They won't communicate any faster with lasers. What they meant to say was, "Improving that badnwidth by a factor of between 10 and 100 with lasers".
Speed? There may be some minor variation in speed among different types of radiation, but if so, I don't think they've measured it.
“I have become friends with many school shooters” - Tampon Tim Walz
(Score: 2) by JoeMerchant on Friday August 11 2023, @07:54PM (1 child)
Lag is the same, completely unable to control Crysis across that link.
🌻🌻🌻 [google.com]
(Score: 3, Funny) by Snotnose on Friday August 11 2023, @10:51PM
You sound young. At my age the Crysis latency on that link would be barely detectable.
Of course I'm against DEI. Donald, Eric, and Ivanka.
(Score: 2, Interesting) by anubi on Friday August 11 2023, @08:30PM
Yeh, I read it that way too. Bandwidth.
Part of me knows exactly what I want to say, but the appropriate word usually comes to me right after I hit "Submit".
That's my biggest frustration with communication. I am even worse at it with spoken communication; no backspace key.
I think I drive my colleagues nuts with the word salads I emit all too often.
"Prove all things; hold fast that which is good." [KJV: I Thessalonians 5:21]
(Score: 2) by John Bresnahan on Friday August 11 2023, @09:33PM (1 child)
High bandwidth, sure, but the ping times are terrible.
(Score: 3, Funny) by Tork on Friday August 11 2023, @10:33PM
🏳️🌈 Proud Ally 🏳️🌈
(Score: 1, Funny) by Anonymous Coward on Saturday August 12 2023, @12:16AM
... is that with so much bandwidth they'll be able to operate using modern programming methods. Of course, with that lag they might still need to cache the javascript and ads locally, and reporting all that tracking data back to the cloud won't be realtime.