To explore caves on Mars and the Moon, take a hint from Hansel & Gretel, say boffins
- Reference: 1677824769
- News link: https://www.theregister.co.uk/2023/03/03/mars_mesh_exploration/
- Source link:
University of Arizona electrical and computer engineering professor Wolfgang Fink and his team took inspiration from the fairy tale pair to develop a rover-and-breadcrumbs system they said will allow exploration deep underground, and in a manner more adaptable than previous concepts. The key to such robotic exploration is communication, and the team have a cunning plan.
Fink and his team presented what they call a "dynamically deployed communication network," or DDCN, in a recently-published [1]paper . Nodes in the network, dubbed "Hansel & Gretel breadcrumbs" are deployed by subterranean rovers that are controlled and monitored by a mother rover that stays on the surface.
If we plan to live on the Moon, it's going to need a time zone [2]READ MORE
If this sounds similar to other subterranean exoplanet exploration concepts we've [3]covered before - it is, but with a few major differences, most crucially how smartly the nodes are deployed.
"One of the new aspects is what we call opportunistic deployment – the idea that you deploy the 'breadcrumbs' when you have to and not according to a previously planned schedule," Fink [4]said .
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Unlike other rover mesh network plans that deploy nodes at a fixed schedule, the Hansel and Gretel system is designed to drop a new node whenever its communication to the previous node becomes too weak. Inter-cave explorer bots, or ICE, will pause whenever their signal is too weak in order to deploy another breadcrumb, and they won't move on until they can validate the new node's connection to the network.
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All of these decisions, Fink said, can be made without input from the mother rover on the surface, as ICE are designed to be autonomous.
The ICE and nodes, which can be equipped with any number of sensors for mapping and data gathering, are both designed for one-way trips into lava tubes and caves. Fink said this ensures resources aren't being wasted going back into the caves to get them out; "it makes more sense to have them go as far as they possibly can and leave them behind," he said.
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Living the tube life
There's a lot of reasons to start exploring the inner surface of the Moon and Mars, the team argues in their paper.
Not least among them is the fact that if life still exists on a place as inhospitable as Mars it's likely to do so underground. Liquid or frozen water may be found in lava tubes and caves on the Moon and Mars as well and if we were planning on settling then caves and tunnels provide a radiation-shielded habitat.
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"Lava tubes and caves would make perfect habitats for astronauts because you don't have to build a structure; you are shielded from harmful cosmic radiation, so all you need to do is make it pretty and cozy," Fink said.
Along with addressing one of NASA's long-standing [10]Space Technology Grand Challenges [PDF] - specifically the challenge of all-access mobility - similar tech that lets roving bots decide how best to build their mesh network could also be useful on Earth, too.
The military and disaster recovery could both make use of such autonomous DDCN tech, as could exploratory missions in the oil, gas and mining industries, Fink and company wrote in their paper.
Just to remember to avoid witches and gingerbread houses, if explorers find them. ®
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[1] https://www.sciencedirect.com/science/article/abs/pii/S0273117723001187?via%3Dihub
[2] https://www.theregister.com/2023/03/01/esa_moon_time_zone/
[3] https://www.theregister.com/2021/02/26/esa_moon_rovers/
[4] https://news.arizona.edu/story/hansel-and-gretels-breadcrumb-trick-inspires-robotic-exploration-caves-mars-and-beyond
[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2ZAHTVlUHml2c4XFEFnZ69QAAAFI&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZAHTVlUHml2c4XFEFnZ69QAAAFI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZAHTVlUHml2c4XFEFnZ69QAAAFI&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZAHTVlUHml2c4XFEFnZ69QAAAFI&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[9] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33ZAHTVlUHml2c4XFEFnZ69QAAAFI&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[10] https://www.nasa.gov/pdf/503466main_space_tech_grand_challenges_12_02_10.pdf
[11] https://whitepapers.theregister.com/
ICE
In Case of Emergency (ice baby...)
Though I wonder about battery life, which is surely going to be the limiting feature unless they can find somewhere to plug them in.
Re: ICE
These are one use nodes (and robot). So long as the nodes have the same life as the robot then your fine.
If you really wanted to, you could even make the first nodes with bigger batteries than the later nodes, because naturally they'll be in work longer. Although the cost of making the nodes to a non-standard design might end up being more expensive than acknowledging that your later nodes will be carrying much more power than they need. Standardisation can be such a god send on weight and cost, even if it's not always the optimal use of resources...
Re: ICE
The device design is the main battery power issue - using a few 5GHz processors and video sensors requires a lot of power but go back to the old days and a sensor or two with a few transistors can work much longer ... about 50 years ago I was working with a researcher who had built a battery powered temperature sensor with a radio transmitter that ran for 24 hours - it was an inch long "pill shape" and small enough they were swallowed by pigs to monitor their intestinal temperature each day in the countryside - I was just repairing the battery powered C120 tape recorder that recorded the received temperature data and was taped to the pigs back for a day too.
If you are only using transistors then much less power is needed.
I wonder if the researchers are coming at this from a robotics background rather than approaching it as RF engineers. I believe there are longwave radio systems designed to work undergroud. People who are both radio amateurs and cavers have spent a lot of time developing in-cave radio communications systems (which get used in cave rescues, when appropriate)... https://bcra.org.uk/creg
Agreed
I used to be a member of both CREG and a Cave Rescue team. I can confirm that Heyphones and similar work very well in Limestone areas with experienced users. And of course the size, shape and tortuous nature of the intervening passage in most UK caves doesn't matter.
(I tried a multi-drop radio system in a UK cave, but signals bouncing off walls and the number of corners in the average cave meant that you had to have many radios close enough to allow for for signal propagation between them, but that tended to have a negative factor on interference. There are so many better alternatives that I only tried it the once. [Valley Entrance, Yorkshire, if you must know, around 1994 (I can't find my notes ATM). I thought that I could get away with 6-7 radios: one at each corner or significant change in passage dimension. The PoC proved that the concept was unfeasible even in that relatively benign environment.])
I would suggest that there may be challenges caused by the rock type on Mars for Heyphones, but any passage will be large in diameter if a rover is to drive down it, and probably straight if it is a lava tube. So, radio net drops will probably be a good solution. Another would be reeling out a 'leaky feeder' of very light-weight wire.
ICE : how many TLAs ?
Internal Combustion Engine
Institute of Civil Engineers
In-Car Entertainment
Immigration & Customs Enforcement
Instructions for conducting examinations
That's just from memory and the first page of google results for "ICE".
anyone got any more?
Hansel and Gretel? Ariadne has prior art.
Sounds like 'Prometheus',...
... where they had comms and mapped the caves,... and still got lost.
Mind you that was a terrible movie.
Famous last words...
"My wifi is down and it's getting dark..."
Olds?
There was a Turbo Pascal program collection called "Hamster World" that my teacher used to teach us programming concepts. The hamster could be put into a small world (a grid with empty spaces and walls). You could walk, turn right (only), look ahead to see if it was a wall, look at the ground, pick up a grain or put down a grain. We had lots of fun to write labyrinth solvers in that. The guy wrote that himself (I believe) as a teaching aid, not sure how widespread it was. Cool dude, actually an overall cool family (his daughter is a year or two older than I and his son is a year younger).