You probably can’t tell from all the way down here, but Earth is developing a pretty big space debris problem.
In fact, Ziggy tells me that, right now, there are at least 17,852 man-made objects floating around up there, and those are just the ones we can track. Start counting the smaller pieces of debris (smaller than 1 cm), and you get numbers in the hundred millions.
It’s a mess.
To combat this problem, engineers from both the University of Glasgow and the Oles Honchar Dnipro National University in Ukraine have been experimenting with what they call “autophage” engines — rockets that essentially devour (read: vaporize) themselves as they ascend, leaving less debris to clutter up low Earth orbit. They also allow more room for cargo.
According to the University of Glasgow, the engines work by consuming a propellant rod that has solid fuel on the outside and oxidizer on the inside:
“The solid fuel is a strong plastic, such as polyethylene, so the rod is effectively a pipe full of powdered oxidiser. By driving the rod into a hot engine, the fuel and oxidiser can be vaporised into gases that flow into the combustion chamber. This produces thrust, as well as the heat required to vaporise the next section of propellant.”
Dr. Patrick Harkness of the University of Glasgow, who is leading the Glasgow side of the project, elaborated, stating that “the rocket structure would actually be consumed as fuel, so we wouldn’t face the same problems of excessive structural mass [as we do with normal rockets]. We could size the launch vehicles to match our small satellites, and offer more rapid and more targeted access to space.”
Sounds good to me. You can read their full paper, titled “Autophage Engines: Towards a Throttleable Solid Motor,” right over here (PDF).
