And "The camera’s 3.2-gigapixel focal plane array comprises 189 4Kx4K CCD sensors with 10 µm pixels. The sensors are deep depletion, back-illuminated devices with a highly segmented architecture that enables the entire array to be read out in two seconds."
Wow that is a huge amount of data from some amazing hardware. This is going to be amazing!
[1] https://kipac.stanford.edu/research/projects/vera-rubin-obse...
edit: I have a PhD in Astronomy, with a focus on Dark Matter, and I measured rotation curves of galaxies myself.
[1] https://www.nsf.gov/news/special_reports/medalofscience50/ru...
Wow, that's a lot of sky for a telescope. Around 3.5° at once. I purchased a telescope specifically to view DSO, and it is ~3 full moons. When attaching my older DSLR, a full moon isn't even 50% of the captured image. Of course, mine's only ~150mm instead of 8.4m. Just putting size in perspective of my own use instead of using school buses or football pitches or basketball type nonsense.
Also, "space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is."
VRO has a 10313mm focal length (vs 8.4m diameter, so f/1.234-- though with a huge central obstruction) illuminating a 630mm focal plane.
I wish that I had.
Being a research astrophysicist at a university or major lab likely requires a PhD and (to achieve tenure) many years of postdoctoral experience.
However, systems like Rubin (which I have worked on) require complex data processing and management systems to make them effective. Building those doesn't require expertise a PhD astronomy — although some level of interest and enthusiasm certainly helps — but rather the sorts of engineering skills that the typical Hacker News reader might possess. Skillsets like that are increasingly vital as astronomy moves towards large-scale, data-intensive infrastructures like Rubin, SKA, etc.
That said, it's certainly true that taking your career down this path isn't likely to be as well remunerated as a career in commercial software development (although that varies a bit with geography).
Should you be interested, check us out at https://www.werkenbijastron.nl/ (probably mainly of interest to folks in Europe) or try the American Astronomical Society Job Register at https://aas.org/jobregister?f%5B0%5D=category%3A514&f%5B1%5D....
VRO's process is considerably more sophisticated, as they do the silicon nitride protective coating. I believe the specific approach on VRO is similar to the one pioneered for gemini: https://www.gemini.edu/files/docman/websplash/websplash2004-...
Fancier protected metal (and dialectic enhanced) coatings have been common in smaller reflectors... but it's quite a big difference doing a fancy sputter coating on a 150mm object vs a 8m one! :P
https://www.youtube.com/watch?v=c-lBKuHqHk0
Grinding and polishing is its own art.
https://www.youtube.com/watch?v=ebqeygLdBYc
None of this looks easy to me.
The 300T telescope movement assembly which can move the 300+ Ton telescope 3.5 degrees in 5 seconds, and the 3.2 GP camera especially are quite a bit harder to build, engineer, and integrate.
I find some of the timelapse of various objects quite fascinating now that we've been recording observations long enough. Seeing the movement around SagA* is amazing. Just the other day, we saw Cassiopeia A over a couple of decades. Some part of my brain knows things are constantly changing in the universe, but at the time scale it seems strange things are noticeably different within our own lifetimes.
How did monolithic mirrors get out ahead again?
The VRO picked the single mirror approach for lower complexity and the ability to lock the primary and tertiary mirrors into one monolithic structure. For this, they accepted some higher fabrication risk.
Source: A friend on the VRO project.
[0] GMT and TMT are at budget risk and TMT faces stiff opposition from Hawaiians who say Mauna Kea is sacred and shouldn't have anything at the summit.
https://elt.eso.org/instrument/
These things are immense. The METIS is supposed to cover 3-13 microns, an impressive accomplishment through the atmosphere. On top of that they can be upgraded and the data can be offloaded with current technology vs. waiting for lasercomm to eventually bring the bandwidth. Even the Hubble is ultimately limited by the chassis. E-ELT expects to do 15x Hubble's resolution and directly characterize exoplanet atmospheres.
Of course if the sky gets gunked up by infinite comsats, all bets could be off.
It’s okay to use “old” equipment to offload from a bottleneck. Space based telescopes are going to be a bottleneck for the foreseeable future. They have severe maintenance restrictions and the more you task swap them the more frequent that maintenance.
So from a constraint perspective, you use ground based observation to do anything that can be done without a space telescope. Including trying to determine which patches of sky justify time on JWT.
Rubin will not be the largest aperture telescope in the world. It’s 8.4m, while Keck is 10m and no longer the largest segmented mirror. Rubin will be the largest single mirror main reflector, beating 8.2m for the previous largest telescopes.
So it’s incremental improvement not retaking a crown.
The largest exclusively lens based ("refractor") telescopes got up to about 1 meter diameter before the trade offs caused a shift to mirrors for larger apertures. Even so, it's common to have lenses near the focal plane of a mirror based ("reflector") telescope to improve the image. Vera Rubin is like that, including a 1.5 meter lens (among others) near the sensor.
The sensor doesn't actually form a blind spot in the image, because it is severely out of focus. Obstructions do affect the pattern of light a star forms on the sensor, but it's all relative, and no mirror or lens can produce perfect images.
Easier to make three smaller mirrors than one big one.
> why mirrors, with their blind spot where the sensor is, instead of lenses?
"Mirrors don't cause chromatic aberration and they are easier and cheaper to build large. They are also easier to mount because the back of the mirror can be used to attach to the mount" [1]. (And there are off-axis designs that avoid obstructing the incoming light.)
[1] https://lco.global/spacebook/telescopes/reflecting-telescope...
Was this equipment pre-existing or purpose-built ?
If the latter, will any get re-used/repurposed for other endeavors ?
It’s also really hard to ship mirrors much larger than this on a boat.
