Dallas Campbell
Hello, welcome to Outer Orbit, one of our little short bonus episodes where we continue the conversation from our main episode focusing in on a particular topic or a particular point of view.
Now then, space is getting crowded, satellites are getting smaller, and so how they move once they're in orbit is changing and today I'm going to be talking with the co-founder and CTO of MagDrive, Tom Clayson, about reinventing in-space propulsion and what it's really like building deep tech for the next era of space. Thank you very much indeed. Let's explain what MagDrive is, what it does.
Thomas Clayson
So MagDrive, yeah, mag for magnetic, drive for driving basically. So basically we are a small electric rocket, which is a satellite component and allows spacecraft to manoeuvre when they're in space. So they'll get launched on a rocket such as like a Falcon 9 SpaceX, dropped off in orbit, but once you're in orbit, you still need propulsion to manoeuvre around. You need it to maintain your orbit, counteract drag.
Dallas Campbell
Even though you're going 17 and a half thousand miles an hour?
Thomas Clayson
You need to maintain your orbit so that you stay on task. So, say you are doing Earth observation, you don't want to deviate from your particular angle. You also need to counteract the effects of drag. At the end of your life, you need to come back down into the atmosphere so you can burn up safely, otherwise you pollute space. But that's only one of the reasons you need propulsion. You also need it because space is getting incredibly crowded. You said space is big, but all the satellites are going to the same location.
Dallas Campbell
It's not that big.
Thomas Clayson
They're all going to the same thin shell.
Dallas Campbell
Well, this is it. I always think we have to sort of think of that thin shell a bit like a new continent. It's a bit like it's prime real estate.
Thomas Clayson
Exactly, yeah. Realistically, all of these satellites are going to like a hundred-kilometre-thick shell around Earth, and they're crisscrossing at the poles. You said, yeah, they're going like seven kilometres per second, but if one's coming the other way, that's 14 kilometres per second.
Dallas Campbell
Yeah, you need to get out of the way.
Thomas Clayson
Yeah, because at 14 kilometres per second, things don't buckle, they don't bend, they just explode if they hit. So you create millions of bits of space debris. So one of these collisions can result in significantly polluting a large portion of space. So being able to actively avoid collisions by having propulsion which is both very responsive and agile but also efficient so you can do it again and again, because we're moving towards a regime where you have to do this every week. I think Starlink does 6,000 collision avoidance manoeuvres every month It's constant.
Dallas Campbell
Well, also, and things like the ISS has to kind of move up and down.
Thomas Clayson
Exactly, but the ISS orbit is nowhere near as crowded as most of them. The real problems are like the sun-synchronous ones where they crisscross at the poles because that's where 80-odd percent of all these satellites go.
Dallas Campbell
And the other thing we mentioned in the main episode briefly, we talked about this, when we were talking about defence. Suddenly the ability to move your satellite near another satellite is important because...
Thomas Clayson
Yeah. If you can get near to another spacecraft, you can be a bad actor, really. You can do electronic warfare, you can use kinetic weapons. You could take them out entirely. But in reality, just the threat is sufficient.
Dallas Campbell
Is that a better way of I think didn't Russia kind of zap a satellite with a laser from Earth?
Thomas Clayson
Well, no, they used an anti-satellite missile. So both Russians and the Chinese have done that and other countries probably have the capability. The issue is that creates millions of bits of space debris, so it kind of buggers you up.
Dallas Campbell
So you don't want to do that for all the reasons.
Thomas Clayson
Exactly. But we're most likely moving towards a realm where satellites want to get close to one another, maybe you want to do something nefarious, maybe you just want to inspect them to see what they can do, right? Getting images of the enemy's capability is very important. Or maybe you just want to be threatening so that you force them to move and therefore stop providing the services which are crucial to the battlefield on Earth and to deplete their propulsion so that you limit their lifetime and capabilities.
Dallas Campbell
And where are we with this? I mean, I mentioned America announced "We have weapons in space." I'm assuming it's that kind of scenario?
Thomas Clayson
You don't need weapons to look threatening when you approach another satellite, right? So this is stuff which has been actively demonstrated like the Chinese satellites which have been imaged doing effectively 1V1 and 1V0 and so forth, dogfights out in geo. Not against other nations, or at least I have no knowledge of that, but like just on their own spacecraft or 1V0 on a virtual spacecraft.
Dallas Campbell
So at the moment, what do satellites use to move about? If a satellite has to move, what's the current tech and what problem are you guys solving?
Thomas Clayson
So there's two main ways. There's chemical thrusters, where you burn a chemical, and that has lots of issues. Firstly, it's very dangerous, and secondly, it doesn't last particularly long.
Dallas Campbell
Run pretty quickly.
Thomas Clayson
Yeah, and then the flip side is ion propulsion, usually Hall-effect thrusters
Dallas Campbell
That was like, because that's an electric drive?
Thomas Clayson
It is, it is, and ours is maybe more similar to that. But we're kind of sitting in the middle and trying to do both. So the current electric propulsion, which is Hall-effect thrusters, there's others like FIPs and a whole zoo of these different technologies. They basically accelerate ions to really high speed, so you get a lot of miles per gallon, but you're really slow.
Now that's great if you want to go to Pluto.
Dallas Campbell
Long-term missions, yes.
Thomas Clayson
But when you're in LEO, it's not so great, right? In LEO, and particularly looking at what people want to do in the near future, they want to rapidly avoid collisions and get back to generating money immediately.
They want to operate in close proximity, not just for the defence angle, but for offering services to repair, to inspect, to build things in space and deliver materials around for like in-space factories, which are hopefully coming shortly. We need propulsion which is more agile, but also has that high efficiency, and that's what MagDrive offers. So we are electric, but we are able to deliver very high power for a short duration, which gives us that very high mobility.
Dallas Campbell
Right, I'm imagining kind of like you're a sort of first and second gear. You got kind of lots of torque in your MagDrive. How does it work? What are you chucking out the back in order to go forward?
Thomas Clayson
Very briefly, the way it works is you charge up the system. So we have supercapacitor module on board that you charge up over minutes or tens of minutes, depending on how much power...
Dallas Campbell
How do you charge that up? Solar?
Thomas Clayson
Yeah, we just collect into the spacecraft power system and it will be almost always solar, which is power in the spacecraft, which then charges us and when charged or partially charged, you can then discharge your MagDrive thruster, and for a few seconds, you get a very high thrust burn and what we're doing during that is we are repetitively at like hundreds of hertz charging a high-voltage capacitor bank on timescales of milliseconds, and then we discharge very rapidly on hundreds of nanoseconds.
So we get these megawatt electrical pulses, so very high-power pulses, which we use to vaporise tiny amounts of metal. So we get these, vaporisation events, which produces this bolt of plasma which is ejected out the back at high speed. We do that hundreds of times a second. Each one of those bits of plasma which is ejected pushes the spacecraft forward. So you do that hundreds of times a second to the spacecraft, it looks like a continual force, right?
For the propellant, we're able to use a wide variety and pretty much any metal works, which gives a lot of benefits over like hydrazine and other chemical propulsion and over noble gas systems. In the short term, it's much easier to use. It's a fraction of the cost, it's vacuum stable, it doesn't need refuelling. I've taken fully fuelled thrusters through airport customs, like security, and usually they don't care, although I did bring Zurich Airport to a standstill the other week, which fun.
Dallas Campbell
I'm sure they were delighted.
Thomas Clayson
That was terrifying. But a funny story for another time. But it's a real benefit, particularly for the smaller spacecraft, to be able to just bolt on your propulsion system and not have to refuel it.
Dallas Campbell
Once it's up there, does it last forever? When you say you don't need to refuel it, if you're kind of vaporising metal, presumably you run out of metal eventually?
Thomas Clayson
Exactly. At the moment, we don't have the capability to refuel spacecraft. There are companies working on that, but presently, we don't have that capability and once we do have that capability, to be frank, you're going to spend a lot of your propellant just getting to the gas station or vice versa.
Dallas Campbell
Yeah.
Thomas Clayson
So at the moment, we're still operating in that regime when the stuff you launch with is the only propellant you've got. In the future, we aim to be able to refuel, and it's not going to be as frequent as a car, but refuel a few times and that brings me onto the second benefit of metals, which is that they're everywhere in space.
Chemical propellants are based on oil and gas, no dinosaurs up there. Xenon, krypton for the Hall effect thrusters, very rare. But metals are everywhere, lunar regolith, asteroids, recycled space debris, that's all potential feedstock for refuelling the MagDrive thrusters.
Dallas Campbell
That sounds quite sci-fi. That sounds quite a long way in the future when we're talking about asteroid mining, lunar regolith.
Thomas Clayson
We may not start with asteroid mining. I mean, we think space debris is the first best option because it's there already and it's kind of getting in everyone's way. So let's use it, right? Rather than burning up in the Earth's atmosphere. But the reality is, until we build a space elevator, which is way in the future.
Dallas Campbell
That's not going to happen, by the way.
Thomas Clayson
Maybe a thousand years from now. The chemistry is pretty clear. It's going to be 100 kilogrammes of rocket for every kilogramme of propellant we launch to space. So if we could start using what's in space to refuel, that enables us to go much further to have longer missions, more advanced missions, enables us to build larger things. It also means that we're able to design missions which are a bit more flexible. Like, when you buy your car, you don't think, "I need to do exactly this many trips to and from work." No, you buy your car and you just refuel it when you need it, right?
Dallas Campbell
For our listeners, what, what does one of your little drives look like? Cause satellites are getting increasingly small, tiny little things now.
Thomas Clayson
So they're quite small. They weigh about three kilogrammes. Total length is 30 centimetres, and cross section is like 10 by 10 centimetres.
Dallas Campbell
Pretty small.
Thomas Clayson
Yeah and with that we aim to service a large range of mass classes. So the smallest spacecraft that would realistically fit one might be like 10-kilogramme spacecraft.
Dallas Campbell
Like they wouldn't go on a Starlink satellite for example?
Thomas Clayson
So Starlink is much larger, but they could very easily because, yes, we'll put one on like a six-year or 10-kilogramme spacecraft, but for Starlink-class spacecraft, which is like 200, 300 kilos, we wouldn't put one, we'd put in an array. So we can put them into grids. So we can do two by two, three by three, four by four, as big as we want really and that means realistically anything from 10 kilogrammes up to 500 kilogrammes is fair game.
Crucially, that means that for the larger spacecraft in particular, you have something which has multiple redundancy on it. It means that you have something which is standardised, because we want to get to the point where we're making tens of thousands of MagDrives per year, which means the quality goes up, the price goes down and also it means that, for a larger spacecraft, you might have one big array, like maybe a four by four as your main drive, and then you can have smaller ones dotted around your spacecraft to help do that rotating and that manoeuvring.
Dallas Campbell
And for you as a company, how much of a sort of game changer is this technology? Is this a sort of technology that you think is going to sort of revolutionise the industry? Are there other people doing similar stuff? Where do you guys sit?
Thomas Clayson
So we very much see ourselves as what I call the core roadmap to like being that space civilisation, which is ultimately what everyone in this industry works towards cause you kind of posed the question in the main podcast, you're like, "Oh, we keep talking about ISAM for like decades." There are some key barriers which we need to knock down to get there. One was cheap launch. Next was computing in space. I think those are solved. The next, and probably the hardest one, is mobility in space. How do we move around? Cause all of these ISAM activities require spacecraft to operate in close proximity. So you need something which is agile to avoid collisions, responsive, but also efficient because if you use chemical propulsion, you will go visit one spacecraft, inspect it, and then deorbit. That's a technology demonstration machine. That's not a business model. You need to go visit a dozen, right? And that's where we want to get to.
Dallas Campbell
Where are you in terms of demonstrations?
Thomas Clayson
Launched two thrusters last year. So two in orbit. Right now we have another four, I believe, going up over the next 12 months. So we do have some early-stage customers we are delivering for. We are simultaneously improving the technology in the lab to improve that reliability, that lifetime and longevity, and the performance as well. We have transitioned from an R&D-focused company to one which is delivering commercial units and looking to scale production.
Dallas Campbell
So do you think this, and ISAM maybe, is this where sort of the UK is really going to demonstrate some clout business-wise and generate some revenue?
Thomas Clayson
I think so and I think we do already have a very strong space capability in the UK. Because we're a small island of 1% of the global population or whatever, but like we do very much punch above our weight in space and we have a lot of heritage. We've been doing space for 50 years over here. Which is pretty cool.
So the UK doesn't need to necessarily own all of ISAM, but I think we can continue to play a really important part in that. Both in providing the key capabilities because MagDrive, like we're not the guys actually doing the ISAM. We're the facilitators. We're the guys selling the pickaxes in the gold rush, right? But there are other companies in the UK which do have the capability to build spacecraft and to do activities, the likes of SpaceForge, which want to manufacture seed crystals in space, or the likes of Astroscale which want to collect bits of space debris.
These are people we want to work with and we want to enable them to go on and be the best version of themselves, basically, and succeed in their business models so that we can succeed in the short term to be the facilitators of ISAM and that industrial revolution in space. But then long term, to actually be the customers and once we're actually mining and manufacturing things in space to buy that material in to refuel our systems to go that much further because we want to open up the wider solar system.
Dallas Campbell
Amazing. Thank you so much, Tom, for coming. I really appreciate
Thomas Clayson
Yeah, Thank you.
Dallas Campbell
And I appreciate you've stayed a little bit longer.
Now then, whatever your role is in the space ecosystem, get in touch with the Satellite Applications Catapult to see how they can help you go even further and if you want more conversations like this, don't forget to subscribe wherever you get your podcasts and of course, you can watch the video version of this on YouTube and don't forget to follow us on social media to stay In orbit.
