2008 Regolith Excavation Challenge
Published on Sep 22, 2007 at 2:00 pm.
2 Comments.
Filed under space exploration.
One of NASA’s Centennial Challenges is the Lunar Regolith Excavation Challenge, hosted together with the California Space Authority. The proposed rules for the 2008 challenge are now available for comment. The prize for winning the competition is $750,000. No doubt, most teams would spend at least that much, if not considerably more, in competing, so the real prize is the prestige of winning the competition.
NASA plans to return to the Moon with a goal of establishing a moonbase by the year 2020, as reported last year in an article by Space.com. There are several reasons for returning to the Moon. Besides the rather obvious science reasons for sending humans to study the Moon in situ, there are engineering reasons for establishing a moonbase. Despite Bob Zubrin’s contention that the best way to do a Mars mission is to go straight to Mars, bypassing the intermediate steps, many scientists and engineers believe that it may be prudent to first establish a moonbase. There are some similarities in moonbase and Marsbase designs. Mars has such low atmospheric pressure that it is nearly a vacuum as far as astronauts are concerned. Both sets of astronauts will need sealed, airtight, pressurized living quarters. Both will need specialized transportation systems on the surface of their respective worlds. And, both will be isolated from the rest of humanity is small enclosed spaces. However, one big difference is that is something bad goes wrong, a moonbase can be abandoned and the astronauts can return to Earth. That is not an option with Mars. A direct return form Mars is not possible at any time. Only when the planets Earth and Mars are properly aligned can a rocket be sent from one to the other. That happens about every two years. So, the argument goes, it would be better to field test a Mars mission with an analogous Moon mission. There is considerable debate about the validity of this argument, of course, but NASA seems committed to this plan, so that is what I will assume may happen.
There have been a vast number of proposed moonbase designs. Some are simply modules that land on the surface of the Moon which are big enough for the astronauts to live and work in. Others are inflatable structures that are shipped to the Moon in compact form and then inflated on site. Still others are composed of intact components shipped to the Moon and assembled to form a structure (much like the way that the ISS is being constructed). One suggestion for a moonbase design that has been incorporated into several of the suggested designs is to have a buried moonbase. Without any atmosphere to shield the lunar surface, the surface of the Moon is constantly bombarded by cosmic and solar radiation. This could be a hazard to the astronauts living on the Moon. One of the cheapest solutions to radiation shielding is to put the moonbase several meters below the lunar surface. The easiest way of doing this is to dig a large trench, but the moonbase in the trench, and then cover it up with the material excavated from the trench. But, this raises a question: How do you dig a trench on the Moon? After all, the traditional earth-moving equipment used here on Earth to dig trenches doesn’t work in an airless environment. Besides, the large earth-moving machines that are used for construction here are also far too heavy to transport to the surface of the Moon. So, something else is needed.
But, in addition to construction needs, lunar excavation equipment may also needed to mine the surface of the Moon. The Moon can be a source of many minerals and substances that are rare or difficult to find here on Earth and expensive to extract. There have been repeated suggestions that it may be economical to mine the surface of the Moon. For many years, Harrison Schmidt, geologist and Apollo 17 astronaut, has been a champion of returning to the Moon specifically to exploit the minerals available on the lunar surface. He has a very good book expounding his ideas and the reasoning behind them.
But, whether the need for excavation is to bury a moonbase to shield it from radiation or to strip mine the Moon’s surface, NASA recognizes a need to have machines that can move large amounts of lunar surface material. Most of the Moon is covered in a material that we call regolith. Strictly speaking, the lunar surface material isn’t “soil,” because the term soil implies a material composed of both minerals and decayed vegetable and other organic matter. The lunar equivalent to soil is composed simply of rock fragments pulverized by eons of meteorite bombardments. So, we use the term regolith to refer to the lunar “soil.” Thus, the lunar equivalent to earth-moving equipment would be regolith excavators. These machines must be able to operate in the very harsh environment of the lunar surface. They likely should be able to operate autonomously, too. While they will obviously have resemblances to typical earth-moving construction equipment, they will have to be specially built for their unique needs.
And, this is where NASA has come up with a very good idea. Rather than doing all of the theory and design work themselves, they are getting private industry and individuals to do some of the work. They have helped create the Regolith Excavation Challenge to get others to think about the needs of a lunar regolith excavator. The idea is that others will do a lot of the initial work, and then NASA can reap the rewards by selecting the best features of the excavators designed for the challenge.
One problem facing tests of lunar regolith excavation is that lunar regolith is unlike Earth soils. The Apollo missions brought back samples of lunar regolith, but only a small amount of real lunar regolith is available — nowhere near enough to practice digging trenches in it. So, some years back, scientists at NASA created a simulated form of lunar regolith called JSC-1A. This material has many of the characteristics of real lunar regolith and it can be manufactured in great quantities. The 2008 Regolith Excavation Challenge, to be held next summer, will use this JSC-1A simulated regolith. A description of an improved form of this simulate regolith can be found here. To further simulate the surface of the Moon, rocks of various sizes will be randomly distributed within the regolith. The excavators will have to be able to handle these rocks without jamming up. The regolith simulant will be placed in a “sandbox” about 4 meters square and 0.5 meters deep (so the challnege won’t be a full scale mining operation like will be needed on an actual moon expedition). A collector bin will be placed near the edge of the sandbox. Competing teams will have 30 minutes to fill the collector bin with as much regolith as possible.
So, if I have any engineering faculty or students reading this blog, then you might think about using this as a student project. And, of course, anyone else interested may want to think about it, too. After all, the more people who are working on the possibility of a moon mission, the more likely it will be to happen. We can’t wait for NASA to do it all. Government agencies move very slowly. If we wait for NASA to do it, we may never make it back to the Moon.
-Astroprof
California Space Authority Logo courtesy CSA
Moonbase art courtesy of NASA
Allen on November 30, 2007 at 10:49 am: 1
Since the surface is mostly dust and powder, it needs a solar powered vaccum cleaner (with a garbage disposal to break up larger rocks).
I suggest you get Dyson in to design it.
Other than that, earthmoving equipment has a great help in the reduced gravity on the moon, I’ve been playing with designs that throw and then catch the regolith
Marcos Passarello on September 13, 2008 at 12:08 pm: 2
I see the diagrams of how to obtain He3 from the moon studying the papers of
University of Wisconsin.The design of mining machine to do this process
that go to the moon, extract He3,
come back to earth and in the middle of the way process the he3.
The methodology” BIA”, a matrix of all problems that the machine
could have in the way to the moon and in the way to earth.
The Impact found simple problems that could have the machine in the way
To the moon, and criticals problems, always is high. The times, for develop
the mining machine. The last matter will be work in Bio-fuels-Diesel,
it could be good for the future analyses of how to process He3 fuels.
I work and develop since years a methodology of Risk Space Management
using standards 4360 AUS-NZ ,NIST -800-30 and in the end i am working
with ISO 31000, and 31010.
Thank you very much