Peter Beck from Rocket Lab and Mark Rocket define space. Peter also talks about Rocket Lab’s Ātea-1 rocket. He uses a model of the Ātea-1 rocket to explain the main parts of the rocket, what these do and how thrust is produced.
Well, space is internationally defined as the von Kármán line, which is 100 kilometres altitude. Basically suborbital is … it’s when you rise up into space and then you fall back down.
So what we did with the Ātea-1 rocket was a suborbital launch. Essentially, it’s a parabolic trajectory. It goes up and comes down pretty quickly so essentially goes up over 100 kilometres altitude and then comes down straight away.
So this is a wind tunnel model of the Ātea-1 we launched last year. So the real one is 6 and a half metres long. I guess we can start at the very top. The nose tip is where… it’s the first interaction between the air and the rocket. So typically what happens on a nose cone is a shock wave. So when we are travelling at greater than the speed of sound, and in our case five times the speed of sound, we break the sound barrier. So a shock wave is propagated off the tip of this nose cone. When the Ātea-1 rocket was ascending up into space, we generated around about 900 degrees centigrade of heat on the nose cone tip, purely from the rocket punching its way through the air, cause it’s travelling so fast.
This here is, in the context of Ātea-1, is the payload section up here, flight computers, recovery systems and separation systems. Now this model is a two-stage vehicle. It separates at a particular point in time. Now the reason why we want a multi-stage vehicle is for efficiency. As you can see, this diameter is larger than that diameter and that’s all about drag. So the most efficient way of getting something up there is to burn a whole lot of propellant very quickly and get rid of any mass that’s not needed.
So we’ll jump to the back end of the rocket. So this is called the booster, this whole thing. Now this booster is completely full of fuel – there is nothing else in there but fuel. The solid fuel component is down here because we run a hybrid system, so hybrid meaning a liquid oxidiser and a solid fuel. So we have a solid fuel port and fuel drain down in the back, and the rest of this is full of liquid oxidiser under very high pressure. And once we initiate combustion, you generate pressure, and then as you generate pressure, you need to eject those gases though the divergent section of the rocket exit cone. Thrust is produced via combustion. Essentially, thrust is defined as the reaction force on a structure as you are ejecting mass out at a very high velocity. If you want to make it even simpler, it’s you’re chucking stuff out real fast and it’s pushing back.