Hacker News Reader

Comment by m4rtink | Hacker News Reader

Cooling in space is hard but not impossible - while current (IMHO stupid without advanced in space infra) space data center projects work with a couple MW, many advanced space propulsion concepts might have to reject hundreds of MW if not a couple GW.

For that you might need more advanced stuff like liquid droplet radiators (https://en.wikipedia.org/wiki/Liquid_droplet_radiator), heat sinks & pulsed operation. Still, it should be eventually doable.

As for space data centers - I think the main issue is the complete lack of in space infrastructure for resource mining, processing and manufacturing & maintenance. It is kinda like building your first practical steam locomotive & the deciding to build directly an airliner. No suitable materils, experience, work force, material sources, etc.

We eventually went from locomotives to airliner, in an incremental manner & expanding the supporting infrastructure to support the ever more ambitious projects.

View on HN

It might be eventually doable, as an experiment or as a flex, sure. But it's never going to come close to being cost-reasonable versus the equivalent infrastructure here on earth.

The security advantages are enormous since access to space is so tightly restricted and controlled, compared to the access potential of a land based data center. Only risk in space is maybe we start WWIII with china and the US directly trading blows. On the ground, any insurgent group can disable your infrastructure. Nothing is truly safe on the surface of the earth. Anyone can strap a bomb on a drone now. See examples from the currently active wars.

What? No, exactly the opposite. It's very easy to jam radio signals and much harder to cut wires. There's a reason the drones on the front lines in Ukraine are dragging fibre optic lines these days.

But more and more Ukraine is using long range drones guided by SpaceX

There's probably so many ways to get around that with space based technology. I can quickly imagine several methods. It depends on what the system is for which might be a good method to use.

Method 1: same as how u2 planes dumped their data: air drop physical media containing data and catch it in the air.

Method 2: laser based emission to specific detectors.

Method 3: baseball style communication: station is under observation and manipulates in some way to serve as a signalling language.

Method 4: numbers station

Method 5: bill yourself as an isp and have some coded syntax that can be supplied in plain sight with the rest of isp traffic.

Method 1: Sure datacenters with latency measured in several hours sure are useful, and can also be intercepted Method 2: Can be jammed by drone with laserpointer. Method 3: Let me just transfer gigabytes of data via physical signalling Method 4: Can still be jammed Method 5: Can in fact still be jammed?

> Sure datacenters with latency measured in several hours sure are useful

Training models takes weeks, are you really worried about a couple hours?

> Can be jammed by drone with laserpointer

Ok, you're just joking

If you’re receiving data optically from a space based laser, yes you are quite vulnerable to your detector being jammed by a much closer laser that doesn’t have to be nearly as powerful to add noise to the signal.

Why do you think GPS is so easy to spoof?

Actually I just googled (clauded?) to learn more about space lasers and found a paper describing interrupting quantum key distribution (tamper evident but not jam proof!) with a 1kw laser on the ground pointed at the satellite! So it really does not take many photons to fuck up an encrypted signal.

“ Vulnerability of Satellite Quantum Key Distribution to Disruption from Ground-Based Lasers”

https://pmc.ncbi.nlm.nih.gov/articles/PMC8659886/

You're going to have to be very close, basically in the direct line between ground station and satellite (which would be airspace that's easily guarded), have a lot of battery/cooling systems to run that laser on what would essentially be a one-way-trip all for disrupting comms for maybe a few minutes tops? And that's just for one ground station, where the blue team can just set another one up a few meters away and be safe. Honestly, you'd probably be better off dumping glitter or water in the sky than trying to actively jam laser comms.

You don’t have to block the signal line of sight in the air, you only need to overpower it from literally anywhere on the ground. I’m ignorant to laser comms so maybe off axis light can be filtered. The paper I posted said it would be simple.

Method 1 runs into the problem of how to replace that media. The DC is in space so it's not like with U2 planes where they landed. Also, I think you mean the keyhole satellites and not U2 planes, since a plane lands at a secure site and can offload media then.

> It's very easy to jam radio signals

Definitely not signals from low earth orbit.

It costs at least 50x more to put a GPU in space than it does on Earth. For that price you can have dozens more capacity in bunkers, under the sea, or on remote islands. Do you think your insurgents are going to get all two dozen? They could travel to the far corners of the earth, destroying 22 of them, and you'd still be ahead. Further, I wouldn't be surprised if a satellite with such a monstrous solar and radiator footprint wouldn't be susceptible to a laser based attack from the ground; either frying it or pushing it into an unstable orbit by vaporizing a few bits.

It costs much more than 50 times because there are no GPUs in space yet. Google is only planning to have some sort of space data centers mid 2030s, if everything works out. A big if, but if they don't start now then we'll never know.

> But it's never going to come close

never? I doubt that.

Technology will improve over time. Eventually I bet it will become cheaper.

Have you tried building in the U.S.? Why do you think it's so expensive to build in the U.S.? It's due to regulation and red tape.

Technology improves, but the laws of physics are constant and absolute (on human timescales).

Thermodynamics says no today, no tomorrow, and no 100 years from now. That's not ever going to change.

What was it the 27th law that says radiating heat in to space does not work? I'm skeptical of the whole thing too, but it's not an impossible engineering challenge, just an expensive one.

The United States is relatively expensive because the world's cash reserves are priced in USD, and a large fraction of the eastern Eurasian continent lives inside a work camp.

The old Chicago School boogeymen of unions, regulations, and red tape are effectors, but they're a pimple on the back of the world-mutating effects of seven-some decades of USD Seigniorage.

I imagine we're going to be living through the reverse of this Seigniorage experiment quite soon.

According to Wikipedia this reduces weight and not the required area. Also AI said the same thing, but I can't trust in it this blindly. So, how smaller would be the required surface area?

Reply on news.ycombinator.com