3 ms·

>the lack of an atmosphere would prove very damaging. Without the buffering of air around drilling tools, dynamic friction will be amplified during drilling tas

>the lack of an atmosphere would prove very damaging. Without the buffering of air around drilling tools, dynamic friction will be amplified during drilling tasks, generating huge amounts of heat. Drill bits and rock will fuse, hindering progress. Should demolition tasks need to be carried out, explosions in a vacuum would create countless high velocity missiles tearing through anything in their path, with no atmosphere to slow them down. (You wouldn’t want to be eating dinner in an inflatable habitat during mining activities should a rock fragment be flying your way…) Also, the ejected dust would obscure everything and settle, statically, on machinery and contaminate everything. [taken from https://www.universetoday.com/12726/building-a-base-on-the-moon-challenges-and-hazards/ https://www.universetoday.com/12726/building-a-base-on-the-m...] I can't imagine keeping those telescopes free of dust will be a trivial task even if you somehow manage to install them without issues - maybe you're imagining a single mobile package deployed to the moon ala the mars rover?

astrodust 8y ago
It's also not a case of dust settling gently on things as it does in an atmosphere, but particles can end up travelling at extreme speeds which effectively sand-blast anything they come into contact with. Lots of engineering problems to solve here.
- dredmorbius 8y ago
  The sandblasting effect was observed during the Apollo missions. Apollo 12 landed about 200m from Surveyor 3, an earlier unmanned lunar mission. https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lroc_20090903_apollo12.html https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/... The total amount of dust displaced per landing is estimated at about a ton, moving at 400m/s (900 mph), and travelling easily 3km, with lighter dust being blasted into orbit. Alan Bean's mission gave us an absolutely unique chance to really measure this blowing dust. After landing, Pete and Alan walked over to the S3 spacecraft and cut off pieces that had been subjected to the intense sandblasting of their LM landing just 160 m away. As Alan rounded the large "Surveyor Crater" and approached the S3 spacecraft he said to mission control via radio, "I thought you said this spacecraft is supposed to be white." (Not exact quote - I'm going from memory here.) Mission Control asked "Why? What color is it?" Alan said "It's brown!" This set off a lot of discussion back here on Earth. What did the lunar environment do to that spacecraft to change it from white to brown??? The leading theory was that radiation changed the chemistry of the paint. That theory held for 40 years. Around me 2008 I traveled to Houston and officially checked out all the white painted pieces that had been cut off the S3 spacecraft and returned to Earth by Apollo 12.... We used Scanning Electron Microscopes, laser scanners, X-ray photoionization spectroscopy, and electron dispersive spectroscopy. We discovered the paint's surface was penetrated by sand-sized (100 micron) lunar soil particles travelling about 400 m/s. Each one made a pinhole in the paint, and we could see the soil particle lying in the bottom of each tiny hole. http://www.collectspace.com/ubb/Forum29/HTML/001900.html http://www.collectspace.com/ubb/Forum29/HTML/001900.html
credit_guy 8y ago
Very nice link, thank you. Yes, building anything on the Moon won't be easy. Let me just add here some other obstacle not mentioned elsewhere: you can't build a "spaceport" on the Moon. Every lunar landing will result in lots of debris flying at bullet speed for kilometers without any air to brake it. More precisely, some of the debris will acquire escape velocity, some less, so some will end up thousands of kilometers from the landing site. But that doesn't mean solutions can't be found. I personally envision a telescope being covered by a dome with retractable foil layers. During the day, when you face the unobstructed Sun (and the solar wind), you cover up. You use several concentric shells, with a small pressure differential between them, so any small (or large) hole causes only a small leak, rather than a catastrophic rupture. Inside the inner shell you have some atmosphere to help you deal with dust, but it does't need to be 1 atm, it can be 0.01 atm, for example. As the foils get punctured by micrometeorites or the aforementioned particles kicked up at landings, you repair them and ultimately replace them on some rotating basis. If regular airlocks can't fully deal with the lunar just, use multi-level airlocks. Etc, etc. I think pretty much all the problems will have solutions. The only question is what benefit we get out of it, apart from the vague desire to colonize the space? Andy Weir in Artemis only thought of tourism, and (no spoiler) some other application that seems quite unlikely. I personally think telescopes are a better business proposal. I did not think of all the details, but since you ask, I think a mobile package would be a natural first step, and then if it works, a modular solution would be a second one. Many years later, we could end up building the instruments themselves on site, but until then, we'd probably need to bring them from the Earth.
- sliken 8y ago
  Seems silly to worry about such tiny little details. We are going to get countless tons of equipment to the moon and you are worried about some debris flying around? How just having a clean landing pad? I was going to say it's not rocket science, but it is. With gravity being significantly lower, landings will be correspondingly lower energy affairs. Also keep in mind that without an atmosphere there will be significantly higher energy micrometeorites with significant velocities. Those are the threats you need to design around, not some shuttle landing in 1/6th gravity.
dredmorbius 8y ago
Great lnk. Funny thing about devils and details.

astrodust 8y ago

It's also not a case of dust settling gently on things as it does in an atmosphere, but particles can end up travelling at extreme speeds which effectively sand-blast anything they come into contact with. Lots of engineering problems to solve here.

dredmorbius 8y ago
The sandblasting effect was observed during the Apollo missions. Apollo 12 landed about 200m from Surveyor 3, an earlier unmanned lunar mission. https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lroc_20090903_apollo12.html https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/... The total amount of dust displaced per landing is estimated at about a ton, moving at 400m/s (900 mph), and travelling easily 3km, with lighter dust being blasted into orbit. Alan Bean's mission gave us an absolutely unique chance to really measure this blowing dust. After landing, Pete and Alan walked over to the S3 spacecraft and cut off pieces that had been subjected to the intense sandblasting of their LM landing just 160 m away. As Alan rounded the large "Surveyor Crater" and approached the S3 spacecraft he said to mission control via radio, "I thought you said this spacecraft is supposed to be white." (Not exact quote - I'm going from memory here.) Mission Control asked "Why? What color is it?" Alan said "It's brown!" This set off a lot of discussion back here on Earth. What did the lunar environment do to that spacecraft to change it from white to brown??? The leading theory was that radiation changed the chemistry of the paint. That theory held for 40 years. Around me 2008 I traveled to Houston and officially checked out all the white painted pieces that had been cut off the S3 spacecraft and returned to Earth by Apollo 12.... We used Scanning Electron Microscopes, laser scanners, X-ray photoionization spectroscopy, and electron dispersive spectroscopy. We discovered the paint's surface was penetrated by sand-sized (100 micron) lunar soil particles travelling about 400 m/s. Each one made a pinhole in the paint, and we could see the soil particle lying in the bottom of each tiny hole. http://www.collectspace.com/ubb/Forum29/HTML/001900.html http://www.collectspace.com/ubb/Forum29/HTML/001900.html

credit_guy 8y ago

Very nice link, thank you. Yes, building anything on the Moon won't be easy. Let me just add here some other obstacle not mentioned elsewhere: you can't build a "spaceport" on the Moon. Every lunar landing will result in lots of debris flying at bullet speed for kilometers without any air to brake it. More precisely, some of the debris will acquire escape velocity, some less, so some will end up thousands of kilometers from the landing site. But that doesn't mean solutions can't be found. I personally envision a telescope being covered by a dome with retractable foil layers. During the day, when you face the unobstructed Sun (and the solar wind), you cover up. You use several concentric shells, with a small pressure differential between them, so any small (or large) hole causes only a small leak, rather than a catastrophic rupture. Inside the inner shell you have some atmosphere to help you deal with dust, but it does't need to be 1 atm, it can be 0.01 atm, for example. As the foils get punctured by micrometeorites or the aforementioned particles kicked up at landings, you repair them and ultimately replace them on some rotating basis. If regular airlocks can't fully deal with the lunar just, use multi-level airlocks. Etc, etc. I think pretty much all the problems will have solutions. The only question is what benefit we get out of it, apart from the vague desire to colonize the space? Andy Weir in Artemis only thought of tourism, and (no spoiler) some other application that seems quite unlikely. I personally think telescopes are a better business proposal. I did not think of all the details, but since you ask, I think a mobile package would be a natural first step, and then if it works, a modular solution would be a second one. Many years later, we could end up building the instruments themselves on site, but until then, we'd probably need to bring them from the Earth.

sliken 8y ago
Seems silly to worry about such tiny little details. We are going to get countless tons of equipment to the moon and you are worried about some debris flying around? How just having a clean landing pad? I was going to say it's not rocket science, but it is. With gravity being significantly lower, landings will be correspondingly lower energy affairs. Also keep in mind that without an atmosphere there will be significantly higher energy micrometeorites with significant velocities. Those are the threats you need to design around, not some shuttle landing in 1/6th gravity.

dredmorbius 8y ago

Great lnk. Funny thing about devils and details.