Correcting atmospheric abberations is a difficult but tractable problem.
However given the spatial extent of the TMT multiple laser guidestars will be required......also an established technology.
Posted on 04/14/2013 8:36:59 PM PDT by Jyotishi
Building the worlds largest telescope on U.S. soil is a "stupid thing"?
This has to rank up there in the top 100 all time ignorant comments.
No advantave someone just figured out how th scam the Gov out of a Billion dollars! We have a space station for a plat form that does not have to look through miles of atnosphere and as the Gentleman said the Hubble!
They want to laso an Asteriod when the moon is already there!
They want to put it in the /moons orbit! Well how much farther is the effin moon!
Oh by the way ISS hows those algea growing and puter chips goin!
The costliest aspect of space travel is the vehicle to break the bounds of gravity!
Send the stuff build a vehicle @ the ISS.
The Shuttle Sysytem was the ground floor of putting parts and fuel on the ISS Send two welders and plumber to build the thing and Vala! Space travel!
Hexagonal segments which are actively warped into the appropriate shape down to 10's of nanometers.
Correcting atmospheric abberations is a difficult but tractable problem.
However given the spatial extent of the TMT multiple laser guidestars will be required......also an established technology.
The flash on that will have to be gigantic!
All basic research is eventually useful, but the knowledge yield from the Space Station has been really minor when compared to Hubble and the other great telescopes.
> The flash on that will have to be gigantic!
Hey, Obama’s got the cash!
Agreed. And how does one measure “the beginning of time.” If the stars are so many light years away, please explain how that can be proved. Please, please.. I want to know. Already know, but have to hear it now, so lonely. (ha ha)
Wow, 35 times the light gathering ability of the Hale Telescope on Mt. Palomar. Anybody remember Palomar? It was the be all and end all of all ground based telescopes for 40 years. Nothing larger could be built on the ground because a larger primary mirror would crack under and/or be distorted by its own weight. Or so they said. That was before segmented mirrors and thin flexible mirrors with adaptive optics. Man, can’t wait to see the photographs this baby will be taking.
It is an international/private/public effort. I don't believe Gordon Moore considers his donations to be a "scam".
We have a space station for a plat form that does not have to look through miles of atnosphere and as the Gentleman said the Hubble!
Atmospheric correction is a very well established technology.....If you insist on a space based instrument, the James Webb telescope is sucking NASA dry at the moment and should act as a nice compliment to TMT's instruments.
The technology required is well established.....the primary glitches are: 1. the mulitplicity of nations contributing to project...each of which will want to farm the work out on a political rather than good engineering basis....2. the logistics of operation.
For instance, each of the 492 mirror segements will need to be extracted and recoated on a regular basis....and replaced in time for night time operations for which the demand will be insatiable and worth 100's of thousands of dollars per evening....the slightest loss of time on sky will be intolerable.
Very tricky operational logistics...
One of the first things I thought of was some poor slob sneezing...
I went to the Wiki page about this.
It was the usual suspects. Indians saying the mountain was sacred and tree huggers worried about a species of squirrels.
I'm sure it took awhile before all the shakedown artists could be paid.
Science marches on.
>> ...keep them polished in the outdoors on a mountain top...
> One of the first things I thought of was some poor slob sneezing...
With “vog” emanating from the active Kilauea volcano on the same island, that can happen quite easily.
One problem with the moon is the temperature extremes. During the 15 day night it falls to hundreds of degrees below zero, during the 15 earth-day day, hundreds of degrees above. The Apollo missions were performed at local lunar twilight.
The moon is actually a very bad place for a telescope. Especially a large one.
Even though there is very little atmosphere, there is a huge day-night temperature variation: +100 Celsius in the day, as low as -173 Celsius at night.
The materials of the telescope have different thermal expansion rates, and this kills the precision of the telescope.
In the right orbit, a space-based telescope can be in constant sunlight, and the satellite designers can shade whatever parts they want to get any temperature they want.
Plus, it takes much more rocket energy to land something on the surface of the moon than to put it into orbit.
A very real issue is that launching a 100 meter primary mirror, even in pieces is well beyond our current capabilities.
Modern adaptive optics can take out a lot of atmospheric distortion.
I would agree that the best environment for a telescope is to keep it in constant sunlight, but how does the HST handle going through the Earth’s shadow orbit after orbit and still get very crisp photos? It’s orbit is only about 350 miles above the Earth.
The 30m/100 foot primary mirror is divide up into 492 hexagonally-shaped pieces that are each 1.4m (4.6 feet) across. The fairings on an Atlas 5 are four and five meters in diameter which is more than large enough to carry such mirrors.
http://en.wikipedia.org/wiki/Thirty_Meter_Telescope
They make the primary mirror in 492 hexagonally-shaped pieces that are 1.4 meters/4.6 feet in diameter.
This is why it is called a segmented mirror reflecting telescope.
http://en.wikipedia.org/wiki/Thirty_Meter_Telescope
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