Science

Water-prospecting Polaris lunar rover prototype built

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The Polaris lunar water prospecting robot prototyple
The Polaris lunar water prospecting robot prototyple
The Polaris lunar water prospecting robot prototyple
The Polaris lunar water prospecting robot prototyple
Red Whittaker discussing Polaris
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Astrobotic Technology Inc., a spin-off company of Carnegie Mellon University (CMU), has debuted its full-size flight prototype of its Polaris lunar water-prospecting robot. Polaris is specially designed to work in the permanently shadowed craters at the Moon’s poles. Scheduled to be sent to the Moon using a SpaceX Falcon 9 launch vehicle, the solar-powered rover is a contender in the US$20 million Google Lunar X Prize and is tasked with seeking ice deposits that could be used by future colonists.

Serious talk about setting up outposts on the Moon has been bouncing around since the 1940s, but has always come up against the major obstacle of water. With shipping costs to the Moon so high that they make Yeti steaks look economical, the only way that a lunar colony has any chance of success is if there is water already on the Moon. With water, a colony could grow crops, generate air and even make fuel for visiting spaceships. Without it, any stay on the Moon must be a short one.

Red Whittaker discussing Polaris

Given that the satellite is a dry, airless rock with a daytime temperature of hundreds of degrees, this made dreams of permanent moonbases pure fantasy until recent NASA and Indian orbital probes detected possible water deposits at the lunar poles. The ice is there because some of the craters are perpetually in shadow, which keeps it from boiling away.

Unfortunately, this also makes prospecting difficult. The shadows and the high lunar latitude make it hard to use solar power for rovers. Also, the terrain is extremely rugged. Other missions can adapt their objectives to suit areas where a lander can operate, but on the Moon, it’s a matter of going where the ice is.

The Polaris lunar water prospecting robot prototyple

Astrobotic’s answer is Polaris. Designed to operate at the lunar poles, it is purpose built for prospecting. "It is the first rover developed specifically for drilling lunar ice," said William "Red" Whittaker, Astrobotic CEO and founder of the Field Robotics Center at CMU's Robotics Institute. Referring to other robots built by the center to study drilling on the Moon, Whittaker added, "what Polaris does is bring those many ideas together into a rover configuration that is capable of going to the moon to find ice."

Polaris is five and a half feet (1.67 m) high, seven feet (2.13 m) wide, about eight feet (2.43 m) long and weighs 150 pounds (68.03 kg). In addition to its own weight, it can carry another 150 pounds as well as the weight of a drill. With its two-foot (60.96 cm) composite wheels and special suspension, it can travel over rough terrain at about one foot (30.48 cm) per second. It’s built of lightweight alloys and composites chosen because they don’t give off gases that might contaminate samples. Weight is particularly important because of the size of the drill.

The Polaris lunar water prospecting robot prototyple

One tricky bit for Polaris is keeping it powered. The rover is solar powered, which is a problem because the ice it’s looking for is in the shadows of craters. Even under the best conditions, the sun hangs very low in the sky at the poles, so Polaris’ three solar arrays need to be very large and arranged vertically to catch enough light to generate 250 watts of power.

To help with the task, Polaris also uses software originally written for CMU's Hyperion robot that will allow the robot to keep track of its position and make sure it catches enough sun while using the available energy with maximum efficiency.

In the next months, Astrobotic will test and improve Polaris’ vision, navigation and planning software. The flight date for Polaris has not been announced, but once arriving on the Moon, the rover will spend ten days traveling three miles (4.82 km) and drilling ten to 100 holes in the lunar surface. If Polaris manages to survive the 14-day lunar night, the mission could be extended indefinitely.

Source: Carnegie Mellon University

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6 comments
Forward Thinker
Why not just use a nuclear thermoelectric generator like the one on Curiosity? I would expect that would be much more reliable in the conditions of the lunar poles, especially given the time the rover would spend in complete darkness.
Astro Rosaire
The moment you say the word "nuclear" the whole cost of the operation goes up 2 to 3 orders of magnitude. Not just that, but the fuel they use for the radioisotope batteries is in EXTREMELY short supply, as in Curiosity took about a 1/4 of the remaining supplies in the WORLD! (This is a somewhat obscure statement because Russia isn't letting us know how much they have left) The sad fact is that no one is producing this very useful isotope anymore and it could be a very lucrative business. I think a rough estimate is about 15 million for 1 kg.
Pikeman
re; Gwyn Rosaire
Given the mission the robot should either have the solar collectors that can be left in the light and have a long extension cord or use a radioisotope power source. Any industrial Gamma emitter wrapped in tungsten will provide a heat source.
Cyberxbx
Seriously? They are building a SOLAR powered robot to go to the DARK parts of the moon to find ice that will only exist of it stays TOTALLY DARK 100% of the time. Considering the shear size of the thing, i would expect it to have a TEG also. And as a side note... If the government wanted to make the isotopes, it could no problem. Its only artificially expensive. Also, there are already some "waste products" of nuclear fission plants (strontium-90?) that could be used and they are relatively cheap. and I'm sure the moon inhabitants wont mind a bit of radiation up there.
Matthew Bailey
And then what? What do you do with a lump of radioactive material when the mission is done? This is the one place that might be fit for humans and you'd make it a nuclear dump? .... yes..there water on the moon, but don't get too close to it.
Pikeman
re; Matthew Bailey
Your anti-nuclear fear mongering is ludicrous. Neither hydrogen or oxygen become radio active from neutron bombardment and even if it did the water could be safely used to make rocket fuel.
Gamma rays do not cause secondary radiation.