[georgeg23]

An order of magnitude lower launch costs to LEO (about $1K/kg now for Falcon 9) and another two magnitudes with Starship.. is a blocking advantage. Constellations don't make sense otherwise, see history: https://wikipedia.org/wiki/Starlink#Background

Keep in mind lasers don't work to the ground unless there are no clouds and stable atmosphere. RF 10-30 GHz work fine to ground and are directional enough that spectrum can be reused and multiple beams formed with one phased array. The real limitation is ITU regulation on total power flux density on the ground for all constellations in these frequencies.

[techdragon]

Lasers work to the ground better than your implying. ,

Modern laser communication ground stations are designed or bring designed incorporating adaptive optics to significantly improve their resilience to atmospheric turbulence. Clouds remain an issue but most laser communications networks are designed with multiple ground stations to ensure sufficient good weather to provide continuous communications. Also several laser communications providers are designing their systems using relay satellites either MEO or GEO to serve as the space to ground really, centralising the higher power space to ground laser link and more expensive optics, and simultaneously placing them higher up enabling better ability to switch between multiple ground stations in the event of cloud disruption.

The laser communication industry is very small still but it’s growing as ground stations get more standard and economical, with commercial units available for both space and ground sides, for a couple of years now.

[tpc3]

Recent (12/21/22) article on the subject: Laser links are great for satellite relay, but challenges abound for taking it to ground https://spacenews.com/walking-a-narrow-beam-laser-links-are-...

[toomuchtodo]

https://news.mit.edu/2022/communications-system-achieves-fas...

[JumpCrisscross]

> order of magnitude lower launch costs to LEO (about $1K/kg now for Falcon 9) and another two magnitudes with Starship.. is a blocking advantage

If they used it to block, sure. Starlink’s advantage is SpaceX’s margin.

> lasers don't work to the ground unless there are no clouds and stable atmosphere

Relay.

[marcusverus]

> If they used it to block, sure. Starlink’s advantage is SpaceX’s margin.

As long as Starlink competitors use SpaceX to reach orbit, the advantage is realized on both Starlink launches (as savings) AND on competitors’ launches (as profit). Doesn’t that make SpaceX’s advantage 2x their margin?

[JumpCrisscross]

> the advantage is realized on both Starlink launches (as savings) AND on competitors’ launches (as profit). Doesn’t that make SpaceX’s advantage 2x their margin?

Sort of. Every dollar of competitors’ launch margin doesn’t go to Starlink. SpaceX’s near-infinite fundraising capacity, and thus low cost of capital, is far more significant. (There are also orbital trade-offs between imaging and comms.)

[wpietri]

> SpaceX’s near-infinite fundraising capacity

I have to wonder how sustainable this is. From the perspective of an investor, I would not be excited by Tesla being down 70% off peak and Twitter becoming the most notable corporate clusterfuck of the year. Investing in SpaceX these days seems like a bet that the CEO will be so distracted by his other problems that he won't have time to mess with the people actually running it.

[bboygravity]

Do you have ANY substantiation for Twitter being a coorporate failure or are you just parotting the biggest Twitter competitors (newspapers)?

[wpietri]

What I actually said is "most notable corporate clusterfuck of the year".

We don't know how it's actually going. Musk is a notorious BSer, and as a privately held company, they don't have to release actual numbers.

But Musk took a company that was doing just fine, made a weed-joke-priced offer, changed his mind, tried to BS and wriggle his way out of the deal, and grudgingly went through it when it became obvious a chancery court judge was likely to force him to buy it anyhow. With that alone it was probably the most notable corporate clusterfuck of the year.

And that's before the actual takeover, where he loaded it up with so much debt that -- and this is according to him -- it could very well be bankrupt in short order. He then flailed around with his amateur-league management dramatics for months in ways that if you somehow missed, you can Google. All while ignoring a much more valuable company that's the source of his wealth as its stock price plummeted by 70%.

If you think there's a more notable corporate clusterfuck in 2022, please do name it.

[nine_k]

Do efficient 30 GHz masers exist?

If not, how narrow can be made a beam by using a beam-forming phased array 10-20 m wide? The diffraction limit at 30 GHz (10 cm) should be reasonably small.

[mikepurvis]

Also, conventional radio can be steered with multiple transmitters, right? Is there a way to steer laser beams in a solid state way?

[JumpCrisscross]

> way to steer laser beams in a solid state way?

Yes, MEMs and waveguides.

[georgeg23]

Unfortunately not ready for prime time yet, optical beamforming today is only a few degrees steerable angle and single beam. Also low power and poorly focused.

[JumpCrisscross]

> not ready for prime time yet

Totally agree. But the frontier is advancing thanks to LiDAR. And in the meantime, the advantages of laser relay and downlink are vast enough to make mechanical actuation worth it. Particularly for unboosted birds in LEO.

[georgeg23]

Curious how LiDAR tech could be used for high speed communication?

At best that is time-multiplexing, not multiple parallel beams of information?

[JumpCrisscross]

> Curious how LiDAR tech could be used for high speed communication?

Lasers don’t care if they’re carrying data out or on return. The same optics being pursued for LiDAR have applications in communications. Solid-state waveguides and MEMS being examples.