William "Red" Whittaker: Red´s Rovers
Dr. William L. “Red” Whittaker is a principal scientist with the Robotics Institute at Carnegie Mellon University. He is also director of the Field Robotics Center, which he founded in 1986. Projects under his direction include unmanned robots to explore planetary surfaces and volcano interiors, and autonomous land vehicle navigation. Some of this work is funded by NASA’s ASTEP (Astrobiology Science and Technology for Exploration of Planets) and the Mars Technology Program.
|William “Red” Whittaker.
Robotics Institute, CMU
On April 16, Red Whittaker testified before the President’s Commission on Moon, Mars and Beyond about the role robotics will play in the future of space exploration.
Testimony by William “Red” Whittaker
I will speak about robots, although my presentation is deviously entitled, “Go For the Poles.” It’s great to the see the moon and beyond mixed in the agenda, besides that central focus on Mars.
I’m using this polar opportunity just as a context to introduce the impact of some great robot capabilities that are existing on the horizon. But the poles are interesting in that they haven’t been explored on the surface, and offer some incredible resources like volatiles.
I’ve titled a new feature “Magellan routes,” and the idea is that these are routes that encircle some part of a planet that are navigable by robot, with the idea that the sun would never set; (the robot) would never encounter the dark. So you want to think of it as orbiting a planet, but on the surface, and keeping up with the sun. It’s kind of an alien concept for us, since we’re here on Earth, and you have to have a very fast jet for that.
The pole is a fixed point, and the sun clocks around. If we were looking at Mercury, for example, it would take half an Earth year for the sun to get around. Since the Mars poles are tilted, you don’t have to move at all in order to get long periods of persistent light. Instead of holding a fixed point at the pole, you come down a few degrees off the pole, and stay in the light all the time. So the idea here is that although there’s no point that’s always illuminated, there are actually infinite routes that are traversed that are continuously in sunlight.
So this is something you might call a power scenario as opposed to a than a power source. Of course it won’t give you a patent for a perpetual motion machine, but it’s a way to keep going all the time.
So there’s no point, but there are routes, and there are seasonal opportunities on Mars. For robots to follow (the routes), they follow daylight. Right at the terminator they can actually choose their temperate zone. You think of these bodies as being either cryogenic cold or blazing hot, and the reality is that near the terminator you just choose your temperature, and can do it in searches. It is those violent hot/cold cycles that are the bane of equipment on the surface, so this beats so much of that technology. And so you can go around a little feature, go around the pole, go around the whole region.
Image Credit: Robotics Institute
Some of the ways you get away with it is that you can go travel 10 or 12 times faster on the moon than you might here on Earth, in part because there is the gravity advantage – you pay energy for that – and the solar advantage by not having the atmosphere.
So how fast do you have to go? Actually, not very fast at all. It is a creeping speed, but of course you choose your speed because the closer you are to the pole the slower you have to go. The further off the pole that you come, you have to go a little quicker, but these are speeds easily achieved for robots.
By the way, if whatever reason you chose in the “beyond” scenario something like Mercury, the energetics are such that the speeds needed to clock the equator are almost imperceptible motion.
So the real topic is robots, and I just put this out there to say, “What do you need to attract these sort of bold scenarios?” Because it’s real clear that robots will be the first circumnavigators, and the first to the top of the great volcanoes, maybe first to the poles. Whatever explorations we know about on Earth will be by robots first on these planets.
The (robot) community is now a family of thousands, and each of them have these tributary technologies, things like persistent desert travel, self-contained intelligence, circumnavigation.
At the time of Sojourner, (one robot model) was clocking the Atacama (desert). You may recall an era when this model was to be a robot slave to the lander. Of course the breakthrough is to traverse afar and to be self-reliant. In the first outing this (robot) did 200 kilometers, and since then has clocked about 1,000 kilometers, and some say those ranges are not very interesting at the scale of planets. Meaning you certainly wouldn’t buy a family car that was good for 1,000 kilometers.
|The autonomous Antarctic meteor finder, Nomad, uses artificial intelligence to recognize and classify promising rocks
Credit: Carnegie Mellon, cmu.edu
Although it seems quite odd, this is a speed that would do just fine for circumnavigation. It’s also the kind of speed that does fine for sustained travel for doing regional exploration. But it’s interesting that this (robot), even though it put in the distance, didn’t cross the mountains and didn’t get over to the next valleys. The kinds of terrains that are presented actually far exceed the difficulties of the kinds of things we do today, even though those terrains are traversable by many robotic means.
One of the things about watching these robots is that while they are at work, it’s actually a little boring. Because when they’re traversing day after day, kilometers after kilometers, valleys after valleys, even though they have purposes, watching them doesn’t enchant like it used to.
(Another robot model) had two points to it: the first is that it’s a thinking machine, and it’s thinking not about navigation. Right now there’s too much navigation on the brain – getting from A to B – and not so much what is the purpose of the machine when it’s doing that. This one had the purpose of seeking meteorites and in fact discerned five of them. You know that if we put 100 pseudo-meteorites on a table among three or four good ones, it would be very difficult for a human to discern what’s the genuine article. The other (point) is an isotope analog, and the idea that new power sources break open a lot of good things
As for the sun synchrony, the first thing you want to think about it is that solar rays are vertical like a billboard or a shark fin. We’re accustomed to seeing solar at the equator, where there’s a sunrise and a sunset, but if there’s never a sunset, then what you need is a square-rigged sail. You can put it transverse or you can put it longitudinal, and the machine will figure out what phase it has to be in to catch the sun. (One robot model) wandered, sought the sun, powered itself up; at no point in its nine-kilometer traverse was it ever behind the power curve. One of the advantages here is you get three times the productivity just because we hibernate now every night, and then spend time to activate and then deactivate. When its not cyclical like that, you just go all the time.
The next is this autonomy business. The terrestrial standard is now something like a command per kilometer. It’s always appropriate for the terrestrial ambitions to exceed what we fly by an order of magnitude or so, because it takes awhile to deploy. The other notion is this science on the fly, which is the controversial notion of imparting to the robot the capacity to make decisions. This is still kind of a cultural thing.
The approaches in any type of new ambition is to orbit, then land, and then traverse, and sometimes sample return. In many of these venues we’ve already done some of that. No matter what the venue there is an argument for some boldness and ambition.
|Hyperion, the rover used in the Atacama field experiments.
On the moon, there’s a tremendous agenda, particularly around the poles and these unique prospects for volatiles. But beyond that, the resource utilization and experiments call for working machines. There are entire scenarios for habitation that are built around these regions.
On Mars, again the poles with the ice caps and the prospect of volatiles. But these technologies, these robot machines are going to be universal; they’re good for anything. Particularly the high-end capabilities have a great deal of utility in fulfilling bolder scenarios.
|Lunar Clementine mission shows the South Pole of the Moon. The permanently shadowed region center shows evidence of meteor cratering and ice never exposed to direct sunlight.
Credit: NASA/DOD Clementine
And then “beyond,” since you ask – an interesting mission might be to spiral the surface of Mercury. So imagine that you land somewhere, anywhere, maybe near the pole, and you traverse, and since you’ve gone around once, traverse again, and again, and again. There is that capacity then to cross the equator and keep on going so you get that full coverage. I know that’s a little dreamy, obviously, but it kind of casts the bold mission of where do you learn your basics, where do you exercise them and what do you use them for, and how they are in fact useful in a lot of places.
So these robots are quite capable of offering us the poles and many other venues, and the moon is a great place to start, in part because of its accessibility and great energetics. Some advocates seem to actually go for these polar scenarios.
The real story in robotics is that its growth and its technical capability is outpacing Moore’s Law, and that is with or without space enterprise. It is so broadly capable that it is – of course, in this exploration context it’s these driving machines mostly – but in terrestrial commerce it is everything from sub-sea operations to maintenance, agriculture, mining, subterranean operations, infrastructure, toys, tools That is a movement that serves us all.
Related Web Pages
Follow the Sun
Nomad: Extreme Explorers Hall of Fame
Roadtest for Robots
William “Red” Whittaker, Robotics Institute
Defense Advanced Research Projects Agency (DARPA) race
Darpa Grand Challenge Race
Presidential Commission, Moon to Mars and Beyond
Antarctic Search for Antarctic Meteorites Program (ANSMET)
Big Signal Project
Atacama Desert Expedition
Patriot Hills Expedition
Martian Rocks, Robot Retrieves