Category: Moon

The uses for duct tape seem to be endless. From the Apollo missions in the 1970’s to the International Space Station today, duct tape has been used as quick fixes and semi-permanent solutions to a variety of tasks. In a story released today from NASA documenting the events of the Apollo 17 in 1972, duct tape became the saviour of astronauts Gene Cernan and Jack Schmitt as they sped around on the lunar surface in their moonbuggy. Damage to the buggy’s wheel arch could have put the pair at risk and may have curtailed the surface mission (pictured). But with a flash of inspiration and “can do” attitude Cernan and Schmitt found the answer in a roll of grey sticky tape…

It would seem duct tape holds the world together as it is, and it is becoming clear that the tape may hold the frontier of space together too. I recently came across the NASA Astronomy Picture of the Day with a view from the ISS looking over Rick Linnehan as he carried out an EVA during the STS-123 mission in March. As many blogs commented, “wow, even the space station is held together with duct tape!“, duct tape and Velcro did indeed appear to be the best way for astronauts to attach things, fix things and cover up things. In the Great Moonbuggy Race in Huntsville, Alabama, Prof. Paul Shiue of Christian Brothers University even joked that duct tape was his team’s “best engineering tool”. It seems the space station crew agrees with Prof. Shiue as is evident in the photo below.

I think people are surprised that such a common, everyday tool can be utilized in space too, but I’d argue that this kind of versatile and strong tape should be in space doing its bit for space exploration. It seems NASA thinks the same thing. Back in 1972, the use of duct tape turned a potentially dangerous situation into mission success for the Apollo 17 astronauts.

During Gene Cernan and Jack Schmitt’s Moon walk, they employed the use of a moonbuggy to get around the dusty terrain. As is becoming abundantly clear, Moon dust will be one of the biggest challenges to mankind’s efforts on the Earth’s only natural satellite. For starters, this fine Moon “regolith” (dust formed from pulverized rock after countless meteorite impacts) will get everywhere. It is so fine that that it will likely obscure vision and could cause a host of respiratory problems. But the critical issue facing the Apollo astronauts was the dark Moon dust getting stuck to their spacesuits. The moonbuggy was designed to suppress the dust from being kicked up from the surface and spayed over the passengers. Should the spacesuits have a layer of dust over the top, solar electromagnetic radiation would be absorbed very efficiently, causing the astronauts to overheat. At all costs, spacesuits and equipment would need to be “dusted off” to prevent any problems.

Within two hours of the Lunar lander Challenger landing on December 11th, 1972 (at 02:23:35 UTC), Cernan and Schmitt were busy loading the moonbuggy with geology tools and experiments. In a seemingly minor error, the hammer strapped to Cernan’s suited leg caught the buggy’s rear fender and ripped it half off. It may not sound like much; after all who needs a fender on the Moon? But this was a big problem. If they were to use the buggy in this condition, huge plumes of dust would be kicked up (known as “rooster tails”) and showered over the astronauts, sticking to their suits, possibly causing serious overheating issues. Lunar dust is also very abrasive and static, should it get wiped off visors, the glass will get scratched, impeding vision. Joints, latches and hinges would also get severely damaged by the stuff.

Fortunately the astronauts had packed duct tape and were able to do a make-shift job at fixing the fender. Unfortunately the harsh vacuum of space, the continuous exposure to the Sun and the ever present dust caused the tape to lose its “stick”. A more permanent solution was required. After communication with mission control, a solution was found. Using a combination of duct tape and laminated maps, the fender could be reconstructed. The EVA continued and the mission was a success.

See the NASA video of Gene Cernan carrying out duct tape repairs on the Moon »

The Apollo 17 mission is the last time man walked on the Moon, and remains the most extreme place where duct tape was called into use.

For the complete and absorbing story about the duct tape repair job by Gene Cernan, check out the full NASA article…

It happens every month and specifically every time the moon is full. According to scientists, for about three days on both sides of a full moon, the lunar surface could transform from a tranquil, inert landscape to an electrically charged, potentially dangerous environment. During this time, the moon ploughs through Earth’s magnetic “tail” — an extension of Earth’s magnetic field. Out in space, the solar wind stretches out the magnetic bubble that surrounds our planet, creating a long “magnetotail” in the downwind direction. When the moon comes in contact with this field, it could cause lunar dust storms and discharges of static electricity. Future lunar explorers might possibly have to take extra precautions during that time of the month.

“Earth’s magnetotail extends well beyond the orbit of the Moon and, once a month, the Moon orbits through it,” said scientist Tim Stubbs from the Goddard Space Flight Center. “This can have consequences ranging from lunar ‘dust storms’ to electrostatic discharges.”

When the moon crosses this magnetotail, it comes in contact with a gigantic “plasma sheet” of hot charged particles trapped in the tail. The lightest and most mobile of these particles, electrons, pepper the Moon’s surface and give the Moon a negative charge.

Scientists say that on the Moon’s dayside this effect is neutralized somewhat by sunlight. The ultraviolet photons knock electrons back off the surface, keeping the build-up of charge at relatively low levels. But on the nightside of the Moon, where it’s cold and dark, electrons accumulate and voltages can climb to hundreds or thousands of volts.

Stubbs said that astronauts walking across the dusty charged-up lunar terrain may find themselves crackling with electricity like “a sock pulled out of a hot dryer.” Touching another astronaut, a doorknob, a piece of sensitive electronics—any of these simple actions could produce an unwelcome zap. “Proper grounding is strongly recommended,” Stubbs said.

Moon dust could become charged enough to actually lift from the surface. There’s evidence from the Surveyor 7 lunar lander that when sufficiently charged-up, lunar dust particles could actually float above the lunar surface. This dust could cause problems as it clings to spacesuits, clogs machinery, scratches helmet faceplates (moondust is very abrasive) and generally make life difficult for astronauts.

Much of this is pure speculation, however, Stubbs said, as no one has been on the moon during this time. “Apollo astronauts never landed on a full Moon and they never experienced the magnetotail.”

The best direct evidence of this event comes from NASA’s Lunar Prospector spacecraft, which orbited the Moon in 1998-99 and monitored many magnetotail crossings. During some crossings, the spacecraft sensed big changes in the lunar nightside voltage, jumping from -200 V to -1000 V, according to Jasper Halekas of UC Berkeley who has been studying the data.

Scientists also say this phenomenon would be worse during a solar storm.

More research will have to be done regarding this monthly cycle and how it might affect those living on the moon in the future.

Original News Source: Science @ NASA

NASA is exploring the possible designs for lunar bases, intended for an extended stay on the Moon. A NASA official from the Advanced Capabilities Division also said on Friday that they may be inspired by a concept based on the technology of the International Space Station (ISS). Very little official indication about the future of NASA’s lunar policy has come to light, so this is interesting news. Although the statement was suitably sketchy, a six-month extended mission to the Moon seems to be most likely. How does this development compare with the lunar settlement designs already proposed?

When Carl Walz, director of NASA’s Advanced Capabilities Division, says “I would anticipate that we would build something similar as what we are building for the ISS, but maybe something different,” I think we can conclude that his department is keeping its options open as far as the future of Moon bases is concerned. But it seems settlement design isn’t very far along either…

Putting uncertainties in lunar base designs to one side, Waltz did confirm that he envisions a long-term, six-month stay over on the Moon, “We need to establish a long, extended presence on the moon, up to six months — same as the time we spend at ISS,” the veteran astronaut told AFP during a forum on the future of NASA at the University of Miami, Florida. The ISS remains mankind’s best experiment into long-term living in space, so its little wonder the station should be used as a model for Moon bases.

The ISS is due for completion in 2010 and houses three scientists for several months at a time. Also, there is enough room for the regular Shuttle crews who arrive to deliver experiments and attach modules. It’s not hard to imagine a future manned lunar base can be used in a similar way, perhaps have a small long-period contingent of scientists, allowing space for short-term visits.

NASA hopes to return to the Moon by 2020 to build a permanent outpost on our planet’s natural satellite. The settlement will need transportation, communication and power systems (see Building a Base on the Moon: Part 4 – Infrastructure and Transportation), allowing lunar astronauts to have the freedom to carry out scientific research on the lunar surface. Many lunar base concepts utilize local materials to fabricate many aspects of a permanent lunar habitat, and continued research by satellites such as the Japanese probe SELENE will aid future colonists prospect for useful minerals and ores.

“We will live at the moon, work at the moon, do sites at the moon and use its resources.” – Walz

It looks as if NASA is working toward a modular settlement design, using the technology that powers the ISS and would be in keeping with “erectable”, or modular designs. Initially, building Moon bases on Earth (or low Earth orbit) and sending them to the lunar surface appears to be the most viable solution. Once a human presence can be established on the Moon, it seems possible that Mars habitats could be fabricated there and sent to the Red Planet. Exciting times.

More about building a manned base on the Moon:

• Building a Base on the Moon: Part 1 – Challenges and Hazards
• Building a Base on the Moon: Part 2 – Habitat Concepts
• Building a Base on the Moon: Part 3 – Structural Design
• Building a Base on the Moon: Part 4 – Infrastructure and Transportation

Source: Physorg.com

In this exciting but challenging period of space exploration, the time is fast approaching for serious design concepts for the first habitats that will be built on the lunar landscape. In previous articles, we have examined the hazards associated with such an endeavor, we have looked at the structures available to us, we have even detailed a particular hangar-like structure that might use locally mined materials. Now, we look into the possible infrastructure elements that will be needed to support a viable colony on the Moon. Florian Ruess, a structural engineer who is working on the future of habitats in extreme environments, also took some time with the Universe Today to give his opinions on our future on lunar soil…

Imagine trying to build a structure on the surface of the Moon. Two of the biggest obstacles the first lunar settlers will come across are the very low gravity and the fine dust causing all sorts of construction issues. Although it seems likely that the first habitats will be built by automated processes before we even set foot on the moon, fabrication of a settlement infrastructure will be of primary concern to engineers so construction can be made as efficient as possible.

Infrastructure will be one of the most important factors concerning mission planners. How will building materials be fabricated? How will the material be supplied to construction workers? How will precious water and food be supplied to the fledgling lunar colony? Can supply vehicles go from A to B with little effort?

Historic examples of the effectiveness of efficient transportation infrastructure can be seen in the coalescence of cities around rivers (traditionally the quickest way to transport people and material around a country). Canals were instrumental in bringing cities to life during the Industrial Revolution in the UK in the late 18th century. As railway lines linked the East and West of North America in the last half of the 19th century, acceleration in population growth was experienced by people uprooting and “homesteading” the new, accessible farmlands. Over the last 50 years, the “Southern California freeway effect” is responsible for the proliferation of gas stations, restaurants, shops, followed by residential areas for workers – eventually, whole towns and cities are based around the ease of access for transportation.

Future settlement of the Moon and Mars will most likely be based on a similar principle; the success of a lunar settlement will heavily depend on the efficiency of the transport structure.

It seems likely that most transportation around the Moon will depend on wheeled methods, following from terrestrial vehicles and tried and tested “Moon buggies” from the Apollo missions in the 1960s and ’70s. There are some significant drawbacks, however. Addressing this issue, Florian Ruess, structural engineer and collaborator with Haym Benaroya (whose publication this article is based) point out some problems with this mode of transport:

“For any mission there will always be the need for individual transportation and the obvious solution is some wheeled vehicle. But there are a couple of serious issues with this solution:

• Reduced traction. 1/6 gravity and the lunar soil make traction a problem just like [the Mars Exploration Rovers] Spirit and Opportunity on Mars one can get stuck easily or need to much power to get around.
• Dust. Apollo experience shows that a lot of dust is levitated by wheeled vehicles. This dust is hazardous to machines and humans when breathed in.”

– Florian Ruess (private communication)

So traveling around in a modified “dune buggy” might not be the answer for an established Moonbase, some form of road infrastructure would be needed if wheeled transportation is used.

Disturbing dust on the lunar surface is far from being a minor problem. From NASA’s experience with the Apollo missions, by far the biggest contributor to dust generation was the takeoff and landing of lunar modules. 50% of the regolith is smaller than fine sand and approximately 20% is smaller than the “dusty” 0.02mm that preserved the Neil Armstrong’s first boot prints. It is this very fine component of the regolith that can cause a host of mechanical and health problems:

1. Vision impairment
2. Incorrect instrument readings
3. Dust coating
4. Loss of traction
5. Clogging of mechanisms
6. Abrasion
7. Thermal control problems
8. Seal failures
9. Inhalation

It, therefore, seems obvious that dust creation should be kept to the bare minimum as this factor could be a severe hindrance to the infrastructure of the settlement.

Roads are would be the perfect answer to the new lunar colony. They would provide wheeled vehicles with the much-needed traction (thus having a knock-on effect with the fuel efficiency of the vehicle) and may significantly reduce the amount of dust suspension, especially if the road surface is raised above the surrounding regolith. Roads, however, have their drawbacks. They are enormously costly and may be very difficult to build. Fusing regolith to form a tough surface may be an answer, but as pointed out by Ruess, “…this requires enormous energies, which cannot be provided by solar power alone.” So an alternate form of energy would be required to perform such a construction.

Although road construction would be highly desirable, it may not be possible, at least in the early stages of lunar settlement development. One emerging development in alternative space transportation is the vertical take-off and landing method, but as previously stated, rocket-powered take-off and landing produce vast amounts of dust. But should there be multiple bases on the Moon, this might be a possibility, “…a lot of people recommend different solutions for routes that will be used frequently like getting from the landing pad to the settlement or from one settlement to the next,” Ruess adds.

Another solution is an established form of transportation. Totally avoiding contact with the surface, thus cutting down on dust and avoiding obstacles, a lunar cable car might be a viable possibility. It seems likely that such a cable car transportation network would be highly effective. “Very large spans will be possible on the Moon and therefore infrastructure cost not exorbitant,” Ruess points out. This possibility is being seriously considered by lunar settlement planners.

Looking back on the previous articles in the series, Florian Ruess comments on whether lunar bases can be mobile and points out some of the severe difficulties facing settlement planners if locally mined materials are to be used:

“I am not a big fan of mobile bases. Such a system that includes power generation, communications and especially long-term meteoroid and radiation protection does not seem feasible to me. But the wheeled vehicles could be pressurized designs capable of serving several-day-long science missions. This would be a good solution to expand the capabilities of a permanent base.

“Local materials are a crucial yet difficult issue. My research so far has shown that only after a certain presence has been established and experience with lunar issues and materials has been gained we would be in a position to dare and build habitats from local materials. Certainly not before humans set foot on the Moon. And please forget about the much-cited lunar concrete! There are so many showstoppers for this imaginary material that I don’t even want to start mentioning them. The only early local material application I see is meteoroid and radiation protection using regolith as shielding material.”

• Building a Moon Base: Part 1 – Challenges and Hazards
• Building a Moon Base: Part 2 – Habitat Concepts
• Building a Moon Base: Part 3 – Structural Design
• Building a Moon Base: Part 4 – Infrastructure and Transportation

“Building a Moon Base” is based on research by Haym Benaroya and Leonhard Bernold (“Engineering of lunar bases“)

Plus an exclusive interview with Florian Ruess, extreme habitat structural engineer and founder of Habitats for Extreme Environments – HE²

-Florian Ruess, private communication.

Many thanks to Florian Ruess for his time in contributing to this article. For further information about his work and extreme environment habitat designs, visit his website at HE-squared.com.

For more information about the future of lunar settlement, check out the Moon Society and the collaborative resource, Lunarpedia.

Based on what we currently know about the makeup of the lunar regolith, future colonists on the moon will not be able to use the soil on hand to grow food. But in a new experiment, bacteria called cyanobacteria grew quite well in simulated lunar soil. While this wouldn’t be a food source for humans, it would enable lunar soil to be broken down to extract resources for making rocket fuel and fertilizer for crops. This could help with the feasibility of setting up a base on the moon, aiding in reducing costs for certain supplies.

Lunar soil isn’t conducive for growing plants from Earth because many of the nutrients in the soil are locked up in tough minerals that the plants cannot break down. But a group led by Igor Brown of NASA’s Johnson Space Center added the cyanobacteria taken from hot springs in Yellowstone National Park in Wyoming (US), to materials designed to approximate the lunar soil. They found that when water, air and light were supplied, the cyanobacteria grew quite well. Cyanobacteria were found to produce acids that work very well to break down tough minerals, including ilmenite, which is relatively abundant on the moon.

Breaking down the same minerals artificially would require heating them to very high temperatures, which would use precious energy, Brown said. Cyanobacteria, on the other hand, use only sunlight for energy, although they do their extraction work more slowly than heating the soil artificially.

Cyanobacteria typically grow in water-rich environments. They are technically a type of bacteria, but like plants, they produce their own food via photosynthesis.

Brown says he envisions growth chambers for cyanobacteria being set up on the Moon, as part of a multi-step process for making use of the resources bound in the lunar soil. The chambers would be supplied with water, sunlight and lunar soil to allow the cyanobacteria to grow.

Cyanobacteria harvested from the chambers could then be further processed to make use of the elements they extract from the lunar soil. For example, they could be broken down by other bacteria, resulting in a nutrient-rich soup that could be used as fertilizer for food plants grown in hydroponic greenhouses. Methane given off by the breakdown of the cyanobacteria could be used as rocket fuel.

Original News Source: New Scientist