Y Combinator Startup Podcast
00:08:42 · S3, Philip Johnston, S1
[00:08:42] S3: So StarCloud one right now as we speak has just left Chinese airspace, I think. Yeah. Heading to Japan. Yeah. Yeah. It's going quite fast, actually. [00:08:52] S0: Yeah. So it travels around 17,000 miles an hour. It's it's about an hour and a half to do one circumnavigation. [00:08:59] S3: So I mean, by StarCloud four or so, this won't be, like, one. It'll be a giant network sort of covering the Earth, actually. [00:09:08] S0: Yeah. From StarCloud three onwards, we'll have 88,000, and they'll all fly. This one is what... In what they call mid inclination orbit, so it doesn't go over the poles, StarCloud. And and that's another point here on how janky this one is. It doesn't even fly in the right orbit, but at least it it it enables us to test the hardware. The next one will fly over the poles, and that gives us twenty four hour always in the sun. [00:09:32] S1: In order to do that, you need to put thrusters on the satellite to move it into that orbit? [00:09:35] S0: In the end, they will be deployed in that orbit, but you need thrusters anyway to maintain the orbit because you have, you know, drag from the upper atmosphere there.
00:09:35 · Philip Johnston, S2
[00:09:35] S0: In the end, they will be deployed in that orbit, but you need thrusters anyway to maintain the orbit because you have, you know, drag from the upper atmosphere there. [00:09:42] S2: What are the engineering and physics trade offs you have to make this happen? Because what you basically are doing with StarCloud is you're getting infinite energy because the sun is basically the natural fusion reactors. It's a giant mass that generates a nuclear reaction with the giant mass, and you have infinite energy, basically abundant, and lots of space. But as a result of that, which we... We're constrained of that in Earth. You have a bunch of other really hard problems to solve, like things around interconnect, how do you send all the data back and forth back to Earth, how do you handle cooling. People think that space is cold, but actually, there's no... Unlike Earth, there's no air to circulate it back. So you need some crazy solutions with cooling. There's things around radiation to flip the bits in in in processors. And there's probably other things around how to get the solar panels to become really big and expand and many more. I mean, these are the ones that I could think of. I mean, what are... There's, like, so many things that are just so hard to build.
00:10:44 · Philip Johnston
[00:10:44] S0: Yeah. You are correct. There are many engineering challenges to to to be solved. The two biggest ones that are outstanding and, most of our engineering our engineering team is split basically fifty fifty down these two lines is number one, as you mentioned, how do you get rid of this heat in a vacuum? And then number two, how do we make the chips work in a higher radiation environment? Some of the other problems are being solved by other people. You know, the interconnect, we've just signed a contract with SpaceX for our next 20 satellites to have a Starlink laser terminal that gives us very high bandwidth, low latency connectivity. Other people are solving some other parts of this. The the core ones we're solving are that. And so for the first one, for the thermal management side of things, we are building a very large, low cost and low mass deployable radiator. Now radiators in space are are not new. It's not a new physics, you know, solution. It's it's more of a manufacturing and engineering challenge. Because the the, you know, the International Space Station has had a radiator which dissipates, you know, lots of heat already, very similar mechanism. So, a liquid called loop. Well, the challenge with it is making it cheap and light. So our radiator is at least 10 times less mass per watt of dissipation than the ISS radiator and 500 times less cost per watt of dissipation than the ISS radiator. So very low bench... Very easy benchmark to beat on cost for the ISS. But, yeah. And then on radiation, it's just a lot of ground testing in different particle accelerators. So we've done several rounds of testing at the Brookhaven National Lab particle accelerator for heavy ions. And also the... There's a cyclotron for high velocity protons down in Knoxville. So we ship all of our hardware down there. My cofounder Adi runs in and out wearing this protective thing. Adi is a lunatic when he comes to this stuff. He's like, oh, yes. It's the same as flying transatlantic. Don't worry about the radiation. So, yeah, basically, you expose it over a twenty four hour period to the same radiation dose that you would have in a five year mission. And then that... All of that telemetry and data then informs our choice on both shielding and software to mitigate bit flips.
00:12:41 · Philip Johnston, S1, S2
I think we're the only people in the world now that know where both an H100, a B200, H200 will fail if you blast it with high velocity protons and heavy [00:12:49] S1: Do you have to change any of the underlying electronics to solve the problem, or you just build shielding around it? [00:12:54] S0: Both. Both. So we do build shielding around it. There's a... A lot of it is just component selection. So for example, all of the SSDs, all of the power delivery system, all of the power converters and everything else, we we test 10 components and whichever the best one is, we pick. We're trying not to use space grade rad hard components. We're trying to use off the shelf like automotive style components because it's way cheaper. And most people have never tested those in radiation chambers. [00:13:21] S2: I think that's one of the secrets of how SpaceX has actually reduced a lot of the cost of a lot of the satellites as well. They use not space graded electronics, which would be extraordinarily very expensive. But instead, you take regular components that there's a supply chain and run through all the tests and make sure if it works. And I think, actually, this is one of the things that Astranis does as well, to make sure that telecommunication satellites actually work in space. Because they're they're also in in GEO, which has more radiation. Yeah. Are you in GEO as well? [00:13:53] S0: No. We're we're in LEO. Okay. [00:13:54] S1: When you first told people that you were gonna put data centers in space, what were people's reactions?
00:13:54 · S1, Philip Johnston
[00:13:54] S1: When you first told people that you were gonna put data centers in space, what were people's reactions? [00:14:02] S0: For a very long time, their reactions was, this is the dumbest thing I've ever heard. So the... Yeah. We we we tried to... We we actually applied to YC once and we got... Actually, we had... We then tried to raise and it took... We tried to raise 2,000,000 at 10 posts on a safe. It took three months and we got rejected from at least a 100 VCs. And then even after YC, when we went out to raise after demo day, I think we got rejected from at least 20 VCs before we got to the first the first check. [00:14:30] S1: This is one of these ideas that was, like, extremely unpopular with investors. And if you had believed the... If you had listened to what all the investors were telling you, you would have quit and not ever done this idea. I'm curious. Why did people tell you that they were not investing, and what did they get wrong?
00:14:30 · S1, Philip Johnston, S2
[00:14:30] S1: This is one of these ideas that was, like, extremely unpopular with investors. And if you had believed the... If you had listened to what all the investors were telling you, you would have quit and not ever done this idea. I'm curious. Why did people tell you that they were not investing, and what did they get wrong? [00:14:45] S0: People had a hard time visualizing a world with low cost launch. And and to be fair, we're still not out of the woods on that front. You know, lots of things need to go right with the Starship program for that to make sense. So that... That's one thing. I think it just sounds too sci fi y and to... Yeah. It's a... Make this work, there's a convergence of two factors. One is the launch costs coming down and people have to believe that. The second is it becoming way harder to build stuff terrestrially. Maybe two years ago, that wasn't quite as obvious as it is today. Now people are like, okay, well, they've just banned building new data centers in New York. They're gonna ban it in like seven other states. Now that... Those two things, I think, converged to make it more investable, essentially. [00:15:26] S2: And I think the other thing, after hearing you explain all the engineering and physics, it actually is doable. It doesn't sound like sci fi from first principles. Like, it's actually buildable.