Hobbyists hope to make spaceflight history

A team of Cambridge students are aiming to become the first amateur group in Europe to send a rocket into space. It’s hoped that the Griffin I module will pass the Karman line, which is the 100 kilometre boundary between Earth's atmosphere and outer space.Jamie Russell is the president of the Cambridge University Spaceflight Society...

Jamie - We've actually been around for quite a long time, longer than some of the other space flight societies. It all started with the goal of some high altitude balloons. However, obviously we've come a long way since then, since sending the teddy bear into space, which I think is our most famous mission from that era. Since then, we've launched three rockets in the Martlet series, these were just on the back of some solid rocket motors that you can buy if you go to the right shop. Only now we are starting to develop our own liquid fueled rocket engines, these are by-propellant engines, and we've been testing those and we realise, particularly over Covid, when we had lots of time to design, we actually could send this mission to space on the back of our own engine. So we call this new engine White Giant, it develops 32 kilonewtons of thrust and runs on ipa, Isopropyl alcohol, and liquid oxygen.

Chris - H how big are the rockets?

Jamie - The Martlet series that I mentioned, they were relatively small, but I don't want to say that they are small. They're about four metres tall, so two people stacked on top of each other, so they're pretty, pretty big things.

Chris - Where would you launch them? Where do you do this?

Jamie - The first one was launched in Scotland, actually. But the latter two, we had to go to America for those ones, just for legal reasons. Essentially, the launch ceilings in this country are more limiting than over there. Particularly, there's rules to do with which types of materials, like if you want too many metals. So we went to America, that was in California and we launched in the Mojave Desert. It's really fun.

Chris - Did you have to take the rocket there or did you design here and build some stuff remotely?

Jamie - We designed and built everything in Cambridge back then, and still do. And let me tell you, it's a bit of a logistical challenge to get everything there on time. You've got one weekend to do everything, set everything up and it has to work. So yeah, we're currently preparing to launch another rocket in September time and yes, it's a logistical nightmare to get everybody there and get all of the rocket parts there. And obviously when you're in the Mojave Desert, if you need one bolt and you don't have it, then you're a bit stuck.

Chris - Do you get it back? Do you have a recovery or retrieval system for this rocket or is it a one hit wonder and you've got to start from scratch every time?

Jamie - For this rocket we're launching in September, we do expect to be able to soft land it. It's got a fully custom recovery system that we've designed and built and tested in the Dyson Center at the university's engineering department. So we do expect it to land slowly.

克里斯,一个降落伞吗?

Jamie - Onto a parachute, yeah, it should land at about 20 miles an hour. So everything should be just fine. However, there's a lot of risk associated with space flights, and so we think it'll work, however we shouldn't expect it to return. There's no one hundred percent here at all.

Chris - How high will that one go?

Jamie - Aquilo will be going to three kilometres.

Chris - So it's 3% of the way to where you want to be, but presumably you start small, and you solve problems incrementally until you go for the big one?

Jamie - So it's the logistical challenges.There's the challenge of manufacturing and learning how all those processes work and interacting with what we call 'cots' components, commercial off the shelf components. So interacting with those is quite difficult. And this is just a little learning experience on the way to that big goal that we've got at the end of the road.

Chris - And how long before we're at the point where you are making a genuine shot for space, as in a hundred kilometres up?

Jamie - Well, of course we need the motor for that. I mentioned White Giant - we hope to be testing that in December. And once you've got the motor, the rest of the rocket is 'relatively', I'm using big air quotes here, straightforward. So you can expect it to happen not too far after that. I'm reluctant to put a firm date on that. But the engine is the real cornerstone of this that we really need to get right first.

Chris - So you solve the guidance, the other materials side of it. So you know you've got something that flies, it flies in a straight line and you can track and recover and so on. And then it's a question of packing a bigger and bigger engine in to give it more of a kick to get it higher?

Jamie - So Griffin will be a completely bespoke rocket. It won't be similar to Aquila, but there's a couple of parts that we are designing for Aquila that we've taken strong inspiration from. But everything will be bespoke for Griffin designed around this huge motor, 32 kilonewtons, that's three tons of force. We'll be accelerating at 5G off the pad. Everything will be bespoke for that, but it's mostly a case of just multiplying things, although there's a lot of challenges associated with going 4,000 miles an hour.

Chris - It's quite quick, isn't it? So how do you track it? Have you got telemetry aboard? Are you beaming signals back? Have you got some cameras on there so you can get gratuitous pictures of what it looks like on the way up and so on?

Jamie - Yeah. So cameras will definitely be there. We have to design special mirrors to keep them out of the air flow, because the air outside is 600 degrees C as we're going through it so fast.

Chris - Because it's compressing and therefore heating?

Jamie - Exactly, yes. We're going so quickly that the compression wave is formidable really.

Chris - So that would be like if you put your hand out of a car window and you were doing 4,000 miles an hour, your hand would get hundreds of degrees.

Jamie - Hundreds of degrees.

Chris - Do you have something to deflect the airstream around the camera then, so you can still see?

Jamie - Yeah, that's a requirement, but also the rest of the rocket has to be designed to withstand these kinds of temperatures. I mentioned 600 degrees, that's actually warm enough to melt aluminium. And most aluminium alloys won't stand up to that, but we want to make the rocket out of aluminium, so we have to go through all of these solutions and so we're actually looking at phenolic resins, but this is a whole other research area.