It is a very subtle balance: on the one hand, the desire to go very far in space and on the other the need to have a large amount of fuel to do so. The greater the distance (at least to a certain point), the greater the need for fuel and therefore the size and weight of the ship increases… Which makes it need more fuel… The solution? A rocket that uses parts of the fuselage as fuel.
Typically, a rocket will use multiple stages and burn them one by one to continue moving forward. When one of them has been used, it is detached from the main one to lighten the weight and allow the rocket to be as efficient as possible. Now, a team of scientists from the University of Glasgow, led by Patrick Harkness, has developed a rocket engine that actually consumes part of your body to use as fuel, reducing weight and providing even more thrust to be able to use higher payloads.
As the engine starts, some of the heat melts through the plastic of its own fuselage and melted plastic is introduced into the chamber as fuel to complement the usual liquid propellant.
Using the rocket chamber itself as fuel means it must be transported Less fuel and mass savings can be used with payloads more massive. There are other benefits as well, as the rocket chamber is used in combustion, which will reduce the chances of space debris.
The Harkness team tested their engine, the Ouroborous-3 and managed to produce 100 newtons of thrust. Thrust was stable even during the autophagy stage when the plastic box provided one-fifth of the total propellant used. The results have been published in Aerospace Research Central.
This new design is controllable; In fact, the team demonstrated how it was capable of restarting, accelerating, and pulsing in an on/off pattern, all of which are necessary for an efficient rocket engine.
The concept of an autonomous rocket engine was first proposed and patented in 1938. However, no autophagic engine design was fired in a controlled manner until a research partnership between the University of Glasgow and Dnipro National University in Ukraine achieved this milestone in 2018.
“These results are a fundamental step on the path towards the development of a fully functional autophagic rocket motor – explains Harness in a statement -. Those future rockets could have a wide range of applications that would help boost the UK’s ambitions to become a key player in the space industry. The structure of a conventional rocket represents between 5 and 12% of its total mass. Our tests show that Ouroborous-3 can burn a very similar amount of its own structural mass as propellant. “If we could make at least some of that mass available for payload, it would be a compelling prospect for future rocket designs.”