Manta Ray UUV prototype completes in-water testing

Glad I'm not the only one. Tooke me awhile to figure out.

Same here

Same. I had to read your comment and title several times each before it clicked.

Came here to write a comment along those same lines haha

Same. I was like "oh, so we have caterpillar drive in real life now?" (assuming screw = propeller)

I wonder if there is a name for garden-path sentences which emerge from mis-reading or typos; or, more interestingly perhaps, a name for a garden path candidate sentence—which is being optimistically projected during reading—forcing a misreading.

An interesting sort of confirmation bias, which it is easy to interpret as "pressure from more abstract model layers, informing the word recognition layer"...

Same, and now I'm fantasizing about the Netflix movie about manta rays unscrewing submarines

I was thinking, "That's a rude way to describe manta rays having reproductive problems."

"Uncrewed" is the gender-neutral replacement for "Unmanned" in the robotics industry these days.

I saw an Instagram Reel where someone claimed it could loiter on the seabed for extended periods powered by geothermal, but that sounds pretty fanciful to me.

The article mentions Seatrec that have more information: https://seatrec.com/technology/

Does not ‘seem’ like the right shape for it, but could it use ocean currents ?

Similar idea to those weather balloons we were talking about last year ?

Is that even possible in the ocean ?

It's afaik the only glider type UUV (ed: being looked at by .mil. and production intended. and bigger than the research gliders by far.), afaik. Which is super interesting in itself, for endurance purposes. But perhaps this depth-changing mission profile is also key to its energy harvesting?

Just guessing here, but... it's sinking and rising. Well, perhaps it can take some mass of water onboard & run temperature differential energy harvesting off that. Take on warm surface water, slowly glide down 1000 ft (while going much further forward), then run a thermo-electric generator against the cold deep. Swap water & take 300 gallons of cold water, glide up 1000 ft (and forward), then run a thermoelectric generator against the warmer surface water or the air and/or solar. Repeat ad-infinitum. No idea what kind of power you could pull here but maybe, and it fits with the glider core concept.

And yeah, maybe if you do find an underwater vent you can supercharge? :)

Shout out to The War Zone (TWZ)'s coverage over time. The recent is decent but links their previous which looked about some. https://www.twz.com/news-features/manta-ray-underwater-drone...

TWZ talk about something mentioned elsewhere in the comments, yes, the data-linking challenges are partly tackled by having a "data bubble" that can float to the surface & uplink, who knows, maybe downlink relay too (unspecified). I definitely want to imagine the data bubble as a recursive system, as itself a smaller glider drone, but I'm 100% making that up, is my sci-fi impulse.

This article covers it in more detail:

https://www.defenseone.com/technology/2024/05/giant-military...

“One thing that you notice in underwater vehicle design is you typically can have either a vehicle that lasts very long periods of time but can't really carry anything with it,” Woerner said on a podcast in 2022. “But if you want something that can carry a sensor or payload that is perhaps a larger size or mass, or has a larger energy draw, you tend to need a more traditional underwater vehicle, propeller driven in most cases. And those tend to not have anywhere near the endurance” that the military is looking for.

The ocean itself is full of potential sources of energy, such as currents, waves, and even subtle differences in water temperature or salt levels. But there’s no single perfect source of ocean energy for what DARPA is trying to accomplish.

“If you're interested in maybe closer to surface transport, wave energy is a really great resource, most of the wave energy is distributed near the surface. If you want to go into deeper water, right? That means that wave energy wouldn't be a great resource for that,” Sandia National Laboratory engineer Kelley Ruehl, an advisor on the program, said on the podcast. Similarly, current energy is a very localized resource, where we have tidal streets— those are unique locations in the world. So it's a very specific place that one would need to harvest tidal-energy resource.”

DARPA said PacMar Technologies, another contractor on the Manta Ray program, will spend the rest of this year testing a full-scale energy-harvesting system.

I think what you’re missing is that a nuclear submarine wouldn’t let a UUV “follow it indefinitely.” Also, the submarine can have its own fleet of UUVs.

> A UUV that can find one and follow it indefinitely

Maybe it could find one but it can't follow it indefinitely if it is powered by a non-nuclear engine.

I am and am not at the same time surprised that humor is allowed in this mode of communications.

Why would airmen need to know about a submersible?

Somebody on X caught it: https://twitter.com/SeanMoodyNews/status/1776676474407297224

Given its size, it could hold a number of cheap small satellite communicators (ie garmin inreach) that could be deployed to slowly float to the surface and phone home as needed.

Bouyant antenna cables are old tech, no need for the entire craft to surface.

Although the US (allegedly) no longer operates them, they (and Russia and China) have used extremely low frequency communications stations spread out over miles to communicate with submerged submarines. Tensions are much lower now so submarines can take the risk of surfacing for communications checkins but I'm sure that the ELF stations could be recomissioned fairly quickly if the need arose

That's going to be a drag.

Navy has very, very good antifouling tech. It'll be far less of a problem than you'd think.

Something about this? “Once deployed, the vehicle uses efficient, buoyancy-driven gliding to move through the water..."

Sounds like it gets around by changing buoyancy, which is pretty cool and also probably completely silent.

The same reason that rays and skates have wings, they're useful in any fluid medium, even when they aren't generating lift.

Same reason fish, marine mammals, submarines etc. need fins.

To look like a manta ray?

What the huh? This has to be a joke, yeah? Those things in the sea move out of the way when things that appear threatening move through the area. Why would this be any different to that? Or to any other man made vessel in that same area. I only typed this out in case you're having a brain fart, otherwise I really feel like there should be cameras around like I'm being punk'd.

Have you ever tried to catch a sea-faring animal, with your hands, or a fishing rod, or a net?

Every prototype of anything large like this would be towed around, why would this be different?

I know it's pointless pedantry and there's no reason to argue it, but aren't prototypes inherently "half-done"? If something was "fully done" it wouldn't really be a prototype anymore, but more of a gen 1.

Large ships regularly leverage tugs to get in and out of harbor, this isn't even a little unusual.

It appears to be "giant" in the way that a small private airplane is "giant". It is larger than a sandwich but significantly smaller than all other underwater craft.

I'm guessing, but manta rays are flexible and can form vertical surfaces by how their wings flop. Or maybe they just can flop their wings different amounts to generate differing thrust for turning.

Neither is possible with todays technology. Adding a vertical control surface is a pretty easy solution though.

It is just part of the same vernacular as: UAV (Unmanned Aerial Vehicle), USV (Unmanned Surface Vehicle), and UGV (Unmanned Ground Vehicle). So UUV (Unmanned Underwater Vehicle) lines up.