Thirty Meter Telescope to see cosmos on micro scale (CBC)
By Matt Kwong, CBC News
Posted: Apr 08, 2015 11:00 AM ET Last Updated: Apr 08, 2015 11:00 AM ET
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The TMT's imaging capabilities are expected to be three times sharper than any other optical telescope on Earth, matching resolutions that could be obtained from space. It will also gather more light, boosting the brightness factor beyond the current largest telescope, the 10.4-metre Gran telescope on the Canary Islands.
Carlberg said the completed telescope would typically have a sharpness of about three milliarcseconds, or one-millionth of an angular degree.
If a coin were to be set at a distance of 1,000 kilometres away, for instance, the TMT would be able to spot it as a distinct object.
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Plans for the TMT to be the biggest of its kind in the world wouldn't last long. The European Extremely Large Telescope would take that title by its first light, scheduled for 2024.
The European project's 39-metre-diameter "segmented mirror" would also be larger than the TMT's 30-metre aperture comprising an array of 600 hexagonal mirrors.
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more: http://www.cbc.ca/news/technology/thirty-meter-telescope-to-see-cosmos-on-micro-scale-1.3023824
Oddly written article, jumps around a lot. But it gives you some idea why these new telescopes are such a BFD.
= new reply since forum marked as read
Why don't we use the money to put the materials needed to make a very large telescope in orbit and assemble/build it there robotically?
There would be no need to have adaptive optics to deal with the atmosphere and you would get a lot more very high quality observing time. You could also get access to the full spectrum without having to compensate for what the atmosphere absorbs. In a micro gravity environment you could make a really large aperture instrument with far less mass.
Am I missing something?
Mirrors on earth have to be relatively massive to hold their shape in a gravity field. In micro gravity this is not a significant issue. Instead of making a 30 meter telescope in space why not make one that is 100 meters or far larger. Even if you only made a 30 meter telescope in space it would have far more observing time and far better "seeing" including all wavelengths.
If we make the robotic infrastructure to build a telescope in space there is no reason to suspect it would not be relatively easy to use the same robots for fixes or even upgrades. As an upgrade why not double the diameter of the mirror after you have gotten experience with the first one. It may be easier to build another mirror than trying to add to the existing one.
Fixing or upgrading the primary mirror on earth 
sounds like a hugely expensive undertaking unless it was designed to have additional segments added. If you wanted to double the diameter of the mirror on earth you would have to start by rebuilding the dome. As for the dome in space, do you need one?
When you launch an already build spacecraft from earth, a lot of mass and expense is involved in just bracing the spacecraft to survive launch.
Last edited Fri May 8, 2015, 05:20 PM - Edit history (1)
Thanks for the video links.
Interestingly I think they said they do have a robot for placing the mirror segments in the high bay (on earth).
What about assembling the mirror in orbit or even building it from scratch. Manufacturing/assembling in space has some huge advantages over doing it on earth. Micro-gravity, very high quality vacuum, almost free energy from the sun (you need a small mirror to concentrate it or a solar panel for power) and you don't need any hugely expensive infrastructure to simulate space on earth for testing. Also, you do not have to do tremendous amounts of expensive engineering to build a spacecraft that will survive launch forces and properly deploy when in space. Instead you need launch-able robots (first ones will be expensive) that can be semi-autonomous and/or controlled from earth along with the raw materials for constructing the telescope along with the tools the robot needs to produce and assemble the telescope.
The first telescope may cost more than the 30 meter telescope or even several but once we have build one in space all the infrastructure would be available to build far larger ones that can be built in space at far cheaper prices. Same thing would apply to
infrared, ultraviolet, x-ray, gamma-ray, radio etc. telescopes. A single 30+ meter telescope in space could probably produce more than all of the telescopes on earth both in quantity and certainly in quality of data.
I'm just saying.........
