So the Chilean observatory needs a new telescope, and somehow it's built in California? And how do they find these people to build these telescopes? Is there some kind of hidden niche of experts that go from Zeiss to Canon and then do government work like this? How will this thing be delivered to Chile? How will they hoist it up into the observatory. Even the slightest accident would be devastating.
Wish they'd make a documentary of their work, because it sounds like an adventure
Early development was funded by a number of small grants, with major contributions in January 2008 by software billionaires Charles and Lisa Simonyi and Bill Gates of $20- and $10 million respectively.[30][25] $7.5 million was included in the U.S. President's FY2013 NSF budget request.[31] The Department of Energy is funding construction of the digital camera component by the SLAC National Accelerator Laboratory, as part of its mission to understand dark energy.[32]
In the 2010 decadal survey, LSST was ranked as the highest-priority ground-based instrument.[33]
NSF funding for the rest of construction was authorized as of 1 August 2014.[17] The lead organizations are:[32]
The SLAC National Accelerator Laboratory to design and construct the LSST camera
The National Optical Astronomy Observatory to provide the telescope and site team
The National Center for Supercomputing Applications to construct and test the archive and data access center
The Association of Universities for Research in Astronomy is responsible for overseeing the LSST construction.
As of May 2022, the project critical path was the camera installation, integration and testing.[34]
In May 2018, Congress surprisingly appropriated much more funding than the telescope had asked for, in hopes of speeding up construction and operation. Telescope management was thankful but unsure this would help, since at the late stage of construction they were not cash-limited.[35]
10m Video on the construction, mentioning "twenty years, over a billion dollars."
If people are confused about why the instrument is in Chile while the funding comes from elsewhere: It's because the high deserts of Chile have some of the best atmospheric conditions in the world for astronomy-- low cloud cover and rain, high altitude, low light polution, and very laminar flow due to the consistent temperatures the air experiences traveling over the ocean.
Mauna Kea in Hawaii is another such golden site (with somewhat better median seeing than the site in Chili), but it's fallen out of favor over pressures to return control of the site to indigenous populations.
> So the Chilean observatory needs a new telescope, and somehow it's built in California?
It's located in Chile but typically the high budget observatories there are run and funded by an international consortium of universities and national government funding. They share time on them. It's for the same reason as the telescopes in the Canary Islands.
In action, the telescope will point at a parcel of sky, 3.5 degrees across—in other words, seven times the width of the full moon.
...
Then, the telescope will move along to the next parcel, and so forth, in a mission to survey the southern sky for years on end.
I first read this as it will take forever to survey the entire southern sky, but they mean it will be operational for years on end.
They already did a full southern sky survey in two weeks using radio telescopes back in 2020. Of course, this new lens will be capturing at a different spectrum.
These cameras are tiled from CCD sensors, inevitably leaving gaps in the coverage. I believe most large telescopes compose multiple images with slightly different pointing into a single image with full coverage. With (two) 15-second exposures, will Vera Rubin do this, or will they live with the gaps?
Vera Rubin / LSST is going to image the sky so many times (hundreds of visits to each part of the sky) that small chip gaps in individual images won't matter in the end.
The survey strategy is driven by completely different concerns, such as detection efficiency for asteroids or supernovae. Cosmetic issues like chip gaps are not a major concern.
Unfortunately the LSST sensors will be extremely disturbed by blooming from bright reflections from satellites. With the exponential increase in satellites projected in the coming years a non-trivial amount of observing power of this amazing instrument will be lost.
Unfortunately once there are enough satellites there will be trails crossing most of the sensors. (The projected densities from starlink and oneweb are truly staggering)
This camera is going to be mounted onto a telescope. You can think of the telescope (specifically, the three large mirrors that guide the light to the camera) as the lens of your DSLR, and this thing as the CCD behind the lens.
The one complication is that this camera itself has a few lenses, which are the final elements in the optical system.
Generally the 'camera' of a telescope is just the sensor part while the 'telescope' is the lens part.
In the case of LSST the camera module also contains some corrective lenses, which serve the purpose of making the focal plane flat and correcting chromatic aberration created by the filter substrate and the vacuum window (the sensor part itself is cryogenically cooled so it has to be in a vacuum).
A telescope is a light collection device so you might be able to use your eye or a camera at the end of an optical telescope, but not a radio telescope.
On earth the sky’s motion blur is predictable and the atmospheric distortions detectable so you want to adjust for both on long exposure shots on earth.
As a camera nerd, it's really something to behold [1].
There's some more older stuff on their website [2]; the test images from 2020 were a whopping 31694x31646.
They have interactive zoomable images for those here [3].
They arent very intersting. They are just grids of ccds, not fundimentally different than those in consumer devices. Rather than build bigger they just stack them into arrays. It is far cheaper to adjust the camera's optical design to use a larger focal plane than create a bespoke sensor with higher resolution/density.
One visual difference would be that they dont have the rgb grid filters of consumer devices, which is why all astronomical images start off as black and white.
These are not off-the-shelf consumer CCDs. These are highly specialized CCDs designed expressly (at Brookhaven National Lab) for this camera - they're essentially unique.[0]
They have to meet very challenging specifications, such as high quantum efficiency (what percentage of photons get detected) across a broad spectral range, fast readout with low noise, and minimal persistence across exposures (meaning that if you image a bright star, you don't see a faint trace of it in the next exposure).
As I understand it, there was no single company that could even manufacture the required number of CCDs on time, so two different manufacturers had to be chosen.
So the Chilean observatory needs a new telescope, and somehow it's built in California? And how do they find these people to build these telescopes? Is there some kind of hidden niche of experts that go from Zeiss to Canon and then do government work like this? How will this thing be delivered to Chile? How will they hoist it up into the observatory. Even the slightest accident would be devastating.
Wish they'd make a documentary of their work, because it sounds like an adventure