Watch This Robotic Intestine Puke Rocket Fuel

The Japan Aerospace Exploration Agency may start to manufacture solid rocket fuel with puking robot intestines

2 min read
Watch This Robotic Intestine Puke Rocket Fuel
Image: Kazumichi Moriyama via YouTube

This is literally a robotic intestine puking rocket fuel. It’s being developed in Japan, by roboticists from Chuo University and JAXA, the Japan Aerospace Exploration Agency.

You’ll be relieved to learn that it’s a robotic intestine puking rocket fuel with a purpose: It’s designed to replicate the peristaltic motion of a real intestine in order to gently mix ingredients to make solid rocket fuel. The researchers say their machine is safer than conventional mixers because the fuel doesn’t experience high shear stress inside the undulating rubber tubing and is never in contact with metal, avoiding the risk of fire and explosions.

The idea is to turn the solid rocket fuel manufacturing process into a continuous operation rather than a discrete one, replacing rocket fuel mixing bowls that give you fuel in batches with a system that can just continuously pump out fuel instead. It’ll be more efficient, safer, and easier to scale, helping keep solid fuel rockets competitive for small satellite launches.

And that means a robotic intestine puking rocket fuel.

The stuff coming out of the machine represents a rubbery mixture of ammonium perchlorate powder (an oxidizer), aluminum powder (a high energy fuel), and an elastomer binder consisting of hydroxyl-terminated polybutadiene (HTPB). Generally, mixing these things together is done in what look like industrial bread dough mixers, which allows each batch to be carefully controlled to make sure the fuel comes out just right. Also, when you’re mixing up something designed to be more or less as explosive as possible, you want to do it very, very gently.

A peristaltic pumping system is able to mix ingredients both safely and effectively. It works just like your intestine does, with rhythmic contractions moving stuff along a tube, except unlike your intestine, the system is closed at both ends and the stuff is added in the middle, along with pressurized air. As the sections of the tube expand and contract, everything inside gets mixed together. An operational system would likely consist of a long mixing loop that would continuously ingest raw rocket fuel ingredients at one end, and then, er, expel them all mixed together at the other.

Once the fuel has been mixed, it’s poured into whatever shape you need it to take (lots of interesting options here) and cured into a rubbery solid. While the stuff in the video (which was associated with a media event, it looks like) is simulated propellant for safety reasons, this system has successfully mixed real propellant as well, which the researchers fired off in a benchtop rocket test just to make sure that it worked (it did).

There’s more detail in the Robostart article, by Kazumichi Moriyama, below, once you’ve translated it from Japanese, and I was also able to find a 2016 paper by some of the same researchers. If you’d just like to learn more about solid rocket fuel in general, here’s a video from the 1960s showing Thiokol’s fuel manufacturing process. And if you want something a bit more up to date (if less focused), this NASA video shows the steps involved in manufacturing one of the solid rocket boosters for the Space Launch System.

[ Paper ] via [ Robostart ]

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Robot with threads near a fallen branch

RoMan, the Army Research Laboratory's robotic manipulator, considers the best way to grasp and move a tree branch at the Adelphi Laboratory Center, in Maryland.

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“I should probably not be standing this close," I think to myself, as the robot slowly approaches a large tree branch on the floor in front of me. It's not the size of the branch that makes me nervous—it's that the robot is operating autonomously, and that while I know what it's supposed to do, I'm not entirely sure what it will do. If everything works the way the roboticists at the U.S. Army Research Laboratory (ARL) in Adelphi, Md., expect, the robot will identify the branch, grasp it, and drag it out of the way. These folks know what they're doing, but I've spent enough time around robots that I take a small step backwards anyway.

This article is part of our special report on AI, “The Great AI Reckoning.”

The robot, named RoMan, for Robotic Manipulator, is about the size of a large lawn mower, with a tracked base that helps it handle most kinds of terrain. At the front, it has a squat torso equipped with cameras and depth sensors, as well as a pair of arms that were harvested from a prototype disaster-response robot originally developed at NASA's Jet Propulsion Laboratory for a DARPA robotics competition. RoMan's job today is roadway clearing, a multistep task that ARL wants the robot to complete as autonomously as possible. Instead of instructing the robot to grasp specific objects in specific ways and move them to specific places, the operators tell RoMan to "go clear a path." It's then up to the robot to make all the decisions necessary to achieve that objective.

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