Robots - Essential for living in space

For all the expense and danger of sending a person into space, you don’t get a very good worker. Astronauts are hampered by the thick gloves on their hands, the bulk of their spacesuit, and the vision limits imposed by helmets and bright harsh sunlight in space. The story line of Moonwards supposes that the first bases on the moon thrived mostly because of advanced remote operation of highly capable robots. 

If you can build a robot that can replace a human worker for less than a million dollars, you are already breaking even. A spacesuit costs roughly that much (and that won’t change until there are thousands being made each year, which isn’t going to happen unless robots have already blazed the trail so that thousands of people have a place to go). They are also just as prone to breakdowns as robots – perhaps more so, when faced with abrasion by lunar dust, which scratches like tiny knives. If you don’t have to send all the equipment needed to keep people alive and safe, you have a decent budget for sending spare parts and backup systems for robots. 

Remote control of robots from Earth means about a 3 second delay between when you send a signal and when you see the response come back, typically from a camera showing the resulting behavior. That means work will take a long time unless the robots handle basic things on their own – like recovering when they trip, throwing and catching things, bracing or anchoring themselves when they push or pull things, knowing how to pick things up and put them down – all that sort of stuff. We are already close to having robots with all those capabilities. It’s more they need to be able to do it like a 10 year old, not a 3 year old.

The first robots sent face many hazards – the dust like fine shrapnel (with static cling), the unearthly heat of day and cold of night, the radiation, and the possibility of electrical discharges due to a lunar sort of static electric buildup in objects. Most of this can be mitigated by building robot-friendly environments. The ground must be paved – or in our case, we’ve chosen to depict the surface being fused to a depth of 5 cm or so by robotic units devoted to the task, with a combination of ground-penetrating microwaves and focused sun for the top layer. You’ll want to fuse a thin layer of alumina on top of that to make it white, so it reflects as much heat as possible. Asphalt in the summer sun on Earth is nothing compared to a dark paved surface that’s been in the lunar sun for a couple hundred hours straight. And the moon’s surface is literally as dark as asphalt. So, that’s the first order of business.

After that the rest is simple. A single layer of reflective foil or cloth offers more than enough protection from heat for a machine, and in the vacuum environment will also prevent heat soaked into the pavement from dissipating at night quite nicely. Robots as nimble as needed would also be capable of deploying parasols to shade themselves as they move around. Space hardware is already hardened against radiation, all that would need to be added would be a shelter for solar storms, which might damage sensitive equipment. That’s just a matter of piling enough dirt on top of a trench with boards laid across it. And boards adequate for that could be made by the same robots that fuse the surface into paving. They just need a smoothed patch of open dirt. There, they can fuse strips of it, which will cool into rock boards easily lifted from the dirt. Static electric discharges can be prevented by grounding the whole area to prevent buildup of static. That isn’t hard when the surface is a single stony mass. Then you have a robot compound. The robots would venture beyond it with caution, like our early forebears leaving their huts to hunt. 

A few other minor points. You’ll want to have a very capable repair bay, and robots that are easily repaired. So robots will be designed with modular parts easy to swap out, and a repair bay will go up on one of the first missions. Imagine an open can on its side with robotic arms suspended on rails on the ceiling, agile ones like are used for surgery, and shelves at the back full of parts and tools. Such a place is protected from most of the moon’s hostility, and broken robots can limp there or be carried there by their kin. Also you need to be able to excavate by blasting. A lot.  Blasting works fine on the moon, you just need your robots to be able to move out of the range of flying debris before detonating the charges. A few large boulders are very useful here. The ideal development zone has at least two – one far away to hide behind before blasting, maybe even with a lean-to against its far side made of some aluminum panels (robots aren’t fussy), and another beside the trench or pit being created, for anchoring to while digging. A decent number of beach ball sized rocks are also handy as counterweights. Putting a few in the basket of a rover helps it heave on things without tipping over. In Moonwards’ story, these approaches are how we get through the early days.

Everyday Athlete Rover

Back in 2008, the Jet Propulsion Laboratory produced a prototype rover that was to go to the moon as part of the Constellation program. It was called the ATHLETE – All-Terrain Hex-Limbed Extra-Terrestrial Explorer. The program was cancelled and it was never fully developed, but it still inspires as an ambitious, ingenious design for a workhorse, do-everything, go-everywhere robotic rover.

Prototype Athlete rover being testedIt was designed to either roll on wheels or use its legs to walk. Tools could be inserted into a connector on the hub of a wheel so it could do work. Large objects could be carried on its back and then be set down somewhere. It could even split into two 3-legged rovers that could work independently. Moon Town’s Athletes extrapolate that rover into an expanded descendant. They are the general purpose rover and robot of the town. They did most of the building in Moon Town’s early days, still look after most transport, and do everything that isn’t both specialized and routine enough to make a specially designed robot for the job.

Moon Town’s Athletes carry enough battery power with them for a full work day of transport, construction, maintenance, or mining duties. When needed more power can be beamed to them as microwaves so they can recharge. Transmitter towers that send such power are dotted around the rim of Lalande Crater, providing coverage within the crater and up to about 50 km outside it. For expeditions farther out, extra battery packs can be carried.

They have manipulator arms incorporated into their front legs, which allow them to do pretty detailed and delicate work. A separate option is to attach a tool to one of their front wheel hubs, for more brute work. The tools required for the job of the day are placed in a rack in the rover’s body. Switching tools is done quickly and easily by the rover itself, as though from a tool belt.

Each rover has storage space in the sides of its body to haul lots of material. Any object equipped with the right connectors can be latched into corresponding connectors on the belly of the rover, allowing it to sling even very large things under it and carry them around. For this reason, both people and cargo are normally transported in pod containers that have no propulsion of their own. Instead, when ready an Athlete comes, picks them up, and takes them where they need to go. Athletes in most cases are smart enough to do that by themselves, but they can also be remote controlled either from within the pod being carried, or by any station that has been assigned control, be it from a hab, a factory, or from Earth, for that matter.

The agility of Moon Town’s Athletes is legendary. When they navigate autonomously across open terrain, they choose the best of the means open to them to cross the obstacles they encounter. They have been known to hop across the tops of boulders clumped in debris fields, surf the layer of dirt that breaks loose when going down a steep crater wall, and to simply jump through an opening in the ceiling of the huge tubular caves known as lava tubes, calculating that their limbs are capable of absorbing the shock of the fall. 

Athletes come in three sizes. The largest is the size of a brontosaur. Because the scale of Moon Town’s infrastructure tends towards the huge, they are also the most common. They handle most transport, a lot of mining activity, various aspects of ongoing construction and manufacturing activities, and some maintenance things. The medium size is a bit taller than a horse when in travel stance. They take on certain manufacturing and maintenance roles and do some transport. The little ones are on the scale of a smallish dog. They are mostly called on for maintenance, repairs, and gopher duties – they go for tools or supplies, or to get a visual on something, or to just hold something while a more senior robot works on it. 

futuristic version of Athlete rover with ball joints

The Robot Ecosystem

Because robots do almost all manual labor, and always have, the whole way things are done has always been designed around them. This is one of the reasons installations are all so huge. In that paradigm, the distinction between what is a robot, what is a highly automated machine, and what is a vehicle is pretty fuzzy. The giant 3d printers known as Mipps (Melt in place printers) not only receive the plans for items to be made and then make them with no further instructions, they tell the Athletes what to bring them, when and how to help out, and what to do with the finished product when it’s ready. The interiors of factories teem with robot arms shuffling and swinging between the rails and pivot points they work from, passing around components, ingredients, and products, their activities mostly orchestrated by a sophisticated priority formula that analyzes all the requests logged by all machines involved in current jobs before selecting what they will do next. The specialized cargo vehicles that shuttle all day between the Stemp stations (Solar Thermal Energy and Molten Product stations) and the lava tanks, do it all by themselves – figuring out what mix to take where, when to do so, and loading and unloading their hazardous cargo free of spills or burns. Likewise, the ore, gravel, and dirt coming in from a variety of local mines is sorted at the source, and pre-processed in simple steps like sieving, tumbling, mixing, and passing through magnets by the vehicles that transport the material, and they assess what needs to be done with each load.

As soon as they step outside the habs, people of the town are a visible minority surrounded by robots who pay only enough heed to them to avoid harming them and proceed with business usually calculated to be more important than that of the interloping human. They aren’t welcome in the factories, which aren’t designed to be safe for such fragile beings. Inside the habs, a host of service robots attend to most of their needs, often responding without receiving any overt command or deciding proactively to attend to an issue they anticipate occurring in the future. To an increasing degree, all these robots iterate entire systems according to designs of their own. Human input steadily decreases. The effect on the shape and the ambiance of the town is a subtle drift towards a non-verbal robot-human communion.

The Android Experience

Some background is helpful to understanding the situation here. Putting on a space suit and going through an airlock currently takes a long time. Advances in technology might give us the confidence to employ space suits that hold a normal nitrogen/oxygen atmosphere at a pressure equal to that used inside the habitats, in which case the time to get out the door might be reduce-able to something like 5 minutes, no less. If we don’t feel absolutely sure the risk of decompression is acceptably low, then the suit has to use pure oxygen so the occupant is protected against decompression sickness. In that case, not only does the suit have to be donned in a pure oxygen environment, but also the nitrogen dissolved in the user’s body has to all diffuse out. Only then can they suit up and step outside without worry a puncture to the suit could cause loss of pressure great enough to make them sick. That takes hours, there’s no way around it. If you have a suit that is reliable while holding that kind of pressure, then you have to figure out how to make it possible to move around in it freely, which is a tall order. The suits designed for the Artemis program have addressed that by building in a system that can lower the pressure in the suit on the fly, down to 0.3 atmospheres. That makes it easier to bend the joints of the suit. Doing much better than that will require advances in materials science so great it would be out of line to assume they have occurred by Moon Town’s time. Therefore, it is necessary to assume that space suits aren’t a lot different than the best we can do today.

In that situation, Moon Town residents normally prefer to go outside virtually, by controlling an android, instead of taking the time to suit up and go out themselves. If it’s just for a quick task, they can use a simple visor to control the android. It provides a virtual reality view of what the android sees. It also allows the user to control the android through hand movements and voice commands.  For longer outings people usually opt to use advanced interface units. In that case, they step into a sort of exoskeleton suspended at the base of its spine on a stationary frame, also equipped with a visor. On some levels that experience feels more ‘real’ than being out there in a suit. The view isn’t interrupted by a limited pane of glass. The android and the exoskeleton controller are both built to move in a free and natural human way. The bulk of space suits and the pressure they have to exert on the occupant makes natural movement impossible. There is no time limit on how long you can be outside – you will tire out long before the android does. You can scratch your nose. You can pause to take a bite of a sandwich. You can even use the exoskeleton with gloves and shoes that convey the texture of what the android touches or steps on, giving you a more sensitive and accurate sense of touch than comes through the gloves of a space suit and the soles of its boots. And you are entirely free of safety concerns. 

Going out in the cab of a rover is a different experience people choose much more often than going out in a space suit. The range, speed, capabilities and sheer sport provided by that is well worth it. In that case, bringing some visors and having the Athlete load on a few androids is standard. Better equipped cabs even have a few exoskeleton interfaces on board. Bringing along space suits is virtually unheard of. 

Androids are designed to function well on the lunar surface. All their moving parts are sealed inside their various sections – batteries and electronics in the torso, actuators and sensors in the limbs. Joints are protected by a sort of baffles setup between the sealed portion of each one and the exposed rod visible on the exterior. The path particles of dust have to take to reach the interior of a section is long and full of turns, and half way through is a trap consisting of a weakly magnetic surface. This defeats their principal enemy, lunar dirt – on the occasions when they are deployed beyond the town limits, where the ground hasn’t all been fused into pavement. With that handled, they have little trouble handling the heat, the cold, and the radiation. The outdoors is their natural home. They almost never venture beyond the inner door of an airlock or even experience an atmosphere.

For the enjoyment of their human puppeteers, androids are a bit stronger than a person. They are agile and able to navigate any kind of terrain with little difficulty, to the point they can be told to go to a specific place, and after arrival a user then takes over their movement. They can withstand significant strikes and falls. The most important thing is to not to get them too covered in dust, or they will need to be taken apart and cleaned, even with all their defenses. Operating them by exoskeleton remote feels akin to being a minor superhero. You stand on the lunar surface like a native, with startlingly clear vision you can zoom in and out or switch to infra-red. You can wander about as though barefoot, unbothered by the beating sun or biting cold. The face area is covered by a curved elliptical screen that can display a live video feed of the face of the current user, for more intuitive interaction within a group going about together. They are so useful and so fun, racks of them stand ready at numerous points around the town’s exterior installations. Up to a few thousand people can be outdoor virtually at the same time by use of this complement of androids, and some residents have custom androids of their own.