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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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The Bionic-Hand Arms Race

The prosthetics industry is too focused on high-tech limbs that are complicated, costly, and often impractical

12 min read
A photograph of a young woman with brown eyes and neck length hair dyed rose gold sits at a white table. In one hand she holds a carbon fiber robotic arm and hand. Her other arm ends near her elbow. Her short sleeve shirt has a pattern on it of illustrated hands.

The author, Britt Young, holding her Ottobock bebionic bionic arm.

Gabriela Hasbun. Makeup: Maria Nguyen for MAC cosmetics; Hair: Joan Laqui for Living Proof

In Jules Verne’s 1865 novel From the Earth to the Moon, members of the fictitious Baltimore Gun Club, all disabled Civil War veterans, restlessly search for a new enemy to conquer. They had spent the war innovating new, deadlier weaponry. By the war’s end, with “not quite one arm between four persons, and exactly two legs between six,” these self-taught amputee-weaponsmiths decide to repurpose their skills toward a new projectile: a rocket ship.

The story of the Baltimore Gun Club propelling themselves to the moon is about the extraordinary masculine power of the veteran, who doesn’t simply “overcome” his disability; he derives power and ambition from it. Their “crutches, wooden legs, artificial arms, steel hooks, caoutchouc [rubber] jaws, silver craniums [and] platinum noses” don’t play leading roles in their personalities—they are merely tools on their bodies. These piecemeal men are unlikely crusaders of invention with an even more unlikely mission. And yet who better to design the next great leap in technology than men remade by technology themselves?

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