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Do you know anything about development work that's been made regarding manufacturing mirrors in space? I'm not thinking assembling them from pieces, I'm thinkin

by marvin 7y ago

Do you know anything about development work that's been made regarding manufacturing mirrors in space? I'm not thinking assembling them from pieces, I'm thinking more about melting some raw material and using some physical process to create in space something larger.

clmul 7y ago
The manufacturing tolerances for large mirrors are very small, and it seems unlikely that we would be able to do this - note that barely any manufacturing has been done in space. Assembling from pieces on the other hand, is more doable.
ceejayoz 7y ago
I wonder if something akin to glassblowing would work in zero-G.
HorstG 7y ago
Gravity is an issue for mirror production. But it is far less of an issue than tension and deformation during the months- to years-long cooling of the substrate. The temperature and environment control to do that is challenging on earth, fairly impossible in space. Except with maybe a really really huge spacestation as a thermal sink, which we won't get for the next few hundred years I'd guess...
- m4rtink 7y ago
  Aren't the terrestrial mirrors so thick due to the need to survive all the tilting under the strong terrestrial gravity ? I would assume a micro gravity only mirror could be much thinner & thus easier to cool down. Or possible alternative techniques could be used to get the needed reflective surface geometry if it does not need to take gravity and atmosphere into account.
  - HorstG 7y ago
    Yes, but stability against vibration and thermally induced warping is also important. So you could make the mirror thinner than on the ground, but not really thin.
    - petschge 7y ago
      You also need a minimum thickness and stability if you ever want to turn the mirror to point elsewhere.
- LargoLasskhyfv 7y ago
  I've read a novel from Daniel Suarez titled Delta-v. Chapter 31, Alchemist beginning on page 175 and ending on 177 changed my assumptions about that. With not that much suspension of disbelief. It's about chemical vapor deposition at large scale, the chapter, not the whole book. That is about near term asteroid mining. edit: book -> novel
adwf 7y ago
A potentially more interesting solution is liquid metal mirrors, either mercury-based or some sort of ferro-silver suspension managed electromagnetically. A hollow toroid could be spun to provide force and the liquid would naturally form a parabola. There've been a few experiments on earth and it could have huge cost saving potential in space. Instead of having to launch a 8m+ solid mirror machined to perfection, you could launch a lightweight toroidal substructure with a vat of reflective liquid at a fraction of the cost.

by marvin 7y ago

clmul 7y ago

The manufacturing tolerances for large mirrors are very small, and it seems unlikely that we would be able to do this - note that barely any manufacturing has been done in space. Assembling from pieces on the other hand, is more doable.

ceejayoz 7y ago

I wonder if something akin to glassblowing would work in zero-G.

HorstG 7y ago

Gravity is an issue for mirror production. But it is far less of an issue than tension and deformation during the months- to years-long cooling of the substrate. The temperature and environment control to do that is challenging on earth, fairly impossible in space. Except with maybe a really really huge spacestation as a thermal sink, which we won't get for the next few hundred years I'd guess...

m4rtink 7y ago
Aren't the terrestrial mirrors so thick due to the need to survive all the tilting under the strong terrestrial gravity ? I would assume a micro gravity only mirror could be much thinner & thus easier to cool down. Or possible alternative techniques could be used to get the needed reflective surface geometry if it does not need to take gravity and atmosphere into account.
- HorstG 7y ago
  Yes, but stability against vibration and thermally induced warping is also important. So you could make the mirror thinner than on the ground, but not really thin.
  - petschge 7y ago
    You also need a minimum thickness and stability if you ever want to turn the mirror to point elsewhere.
LargoLasskhyfv 7y ago
I've read a novel from Daniel Suarez titled Delta-v. Chapter 31, Alchemist beginning on page 175 and ending on 177 changed my assumptions about that. With not that much suspension of disbelief. It's about chemical vapor deposition at large scale, the chapter, not the whole book. That is about near term asteroid mining. edit: book -> novel

adwf 7y ago

A potentially more interesting solution is liquid metal mirrors, either mercury-based or some sort of ferro-silver suspension managed electromagnetically. A hollow toroid could be spun to provide force and the liquid would naturally form a parabola. There've been a few experiments on earth and it could have huge cost saving potential in space. Instead of having to launch a 8m+ solid mirror machined to perfection, you could launch a lightweight toroidal substructure with a vat of reflective liquid at a fraction of the cost.