New Method Discovered For Making Telescopes On the Moon 135
NASA scientists have discovered a way to craft very large mirrors using carbon nanotubes, some epoxy, a little bit of aluminum, and large quantities of lunar dust. They say the technique will allow the construction of massive telescopes on the moon without the expense and risk of transporting the mirrors from Earth. Douglas Rabin of the Goddard Space Flight Center is quoted saying, "Our method could be scaled-up on the moon, using the ubiquitous lunar dust, to create giant telescope mirrors up to 50 meters in diameter." While this breakthrough was relatively cheap, NASA is currently offering up to $10 million for other good lunar research projects.
First time using extraterrestrial materials? (Score:3, Interesting)
I want a degree in... (Score:5, Interesting)
How cool would it be to design and build huge projects in 1/6 gravity? There would have to be some incredible designs that would just be too fragile to stand up under Earth atmosphere and gravity, and the range of materials you could use would seem limitless. Maybe a nest of lasers to give a long-term boost to an interstellar probe?
There's got to be huge advantages to building in a lunar environment, with raw materials available right there, and the chance to create living space just by drilling and sealing instead of fabricating from scratch.
One of those "next" steps seems hard (Score:4, Interesting)
Getting a large enough volume at room temperature (assuming you need some air pressure too) on the moon to mix it with epoxy and spin it (also presumably at room temperature) might be pretty hard to do without some bulky equipment. Although vacuum coating the mirror blank might seem easier on the moon, as other commentors noted, how do you keep it dust free?
So to summarize...
1. Bring epoxy, carbon nanotubes, aluminum and big spinner to the moon
2. ???
3. Coat resulting lunar dust blank with aluminum to make a mirror
4. Profit?!? (until it's covered with dust)
Lunar mirror fab means big manufacturing changes (Score:4, Interesting)
Lunar telescope manufacturing would require some exciting scientific, engineer, and processing improvements that would also pay off for terrestrial manufacturing.
First, assuming they're not planning to house and employ a standard aerospace company, with 1000 engineers, technicians, and managers on the moon, this would be fully automated. Mirror making is anything but automated. The development of highly automated methods for processing and testing mirrors would be quite a move forward. It would also have direct benefits for conventional manufacturing.
Second, making a mirror on the moon would seem to require a tolerance of risk currently not accepted. Every time a mirror is moved, a crew of people must oversee the affair, sign the (physical) paperwork, and manually inspect the mirror afterwards. For lunar construction, this would have to become an assembly line that ran without that direct oversight, paperwork, or crews. Enabling more efficient methods would certainly benefit normal processes as well.
Moreover, the task of creating such a facility would keep many, many aerospace workers employed for years
Re:First time using extraterrestrial materials? (Score:4, Interesting)
Re:What's the old method ... (Score:4, Interesting)
Re:One of those "next" steps seems hard (Score:4, Interesting)
The moon lacking an atmosphere, and there as such being no weather, the moon dust is quite stable.
It only shifts when something (like an astronaut's boot or a meteorite) pushes it, so the odds of a mirror staying largely dust-free are pretty good.
As to spinning stuff in room temperature on the moon... That part sounds harder
Re:Lunar mirror fab means big manufacturing change (Score:3, Interesting)
http://www.sciencefriday.com/newsbriefs/read/113 [sciencefriday.com]
Anyways, a professor in my physics departement, Ermanno Borra, has been working on a very similar concept for about 20 years. And honestly, it has become pretty much a running joke, seeing how much money he's getting from the government, although he has very few results to show.
He works on liquid mirrors. It uses a liquid that is preferably ferromagnetic and covered with a thin film of silver nanoparticles, so that you can put an array of electromagnets under the spinning mirror to do real-time spatially-continuous adaptive optics. Sounds cool (which it is), but there are a lot of difficulties that come to mind which are presumably common to the project described in TFA.
Firstly, the parabolic shape is always pointing up. Since the mirror is liquid, as soon as you tilt it to the side, it loses its parabolic shape, and becomes useless. Now, the adaptive optics part may help you to try to correct for the distortion, but the best results that Borra managed to get is a correction of a tilting of about a tenth of a minute. Disregard this if the material they use for spinning actually solidifies after a while - you could tilt it afterwards, I guess. Not the liquid one, though Borra has promised a range of 5 to 10 degrees on his device for years.
Even if it becomes hard as concrete, the logistics of tilting a 50-meter wide piece of concrete without any structural deformation is impressive. That means, unless you find a way around this, you'll have to keep your mirror looking up, at all times. So you either place it on the pole, in which case it will be looking at the same place for a very, very long time (until precession slowly moves it around). This is good for doing very deep fields, but hasn't much use otherwise since if there's nothing interesting to look at there, you're stuck there anyways.
Or you can place it anywhere else than the pole, but then you're never gonna look at a given object for more than a couple seconds.
As strong as concrete... (Score:4, Interesting)
myke
Vs. Hubble? (Score:3, Interesting)