While I wasn't involved in its fabrication, I got an invite to the celebration they held yesterday for the DKIST primary's completion. Formerly the Advanced Technology Solar Telescope (ATST), it was recently renamed the Daniel K. Inouye Solar Telescope (DKIST) after the long-serving senator from Hawaii. He led an amazing life and serves as appropriate namesake for an equally amazing telescope - be sure to check out the link about his life. Arriving a few minutes late, the crowd had already gathered and were milling about the optics fabrication lab at the College of Optical Sciences, having already hit the buffet line of sandwiches and veggie trays.
A few minutes later, the speeches started - at left is project scientist Jim Burge describing the many challenges of accurately polishing and testing the mirror - only 75mm (2.9" thick), extremely aspheric (8mm departure from best-fit sphere!), yet finished to a surface less than the size of a glass molecule! The mirror surface can actually be spotted behind his right elbow - more on it later...
After more speeches from the DKIST staffers, it was time for the group shot of those participating towards the successful completion. At left, associate director of Steward Observatory Jeff Kingsley, directs folks surrounding the 4.24 meter primary mirror of DKIST. What is interesting to me is that I used to work in this shop in the '80s, and there wasn't much of a safety culture then. Safety programs were really pushed hard at the Mirror Lab in the 90s, and evidently migrated BACK to Optical Sciences - check out Frank Gacon who was serving as photographer for the event. Forklift with man lift, harness safely tied off, and wrapped in caution tape at floor level! Even more interesting is that the woman at the bottom is Karen, who is in charge of the safety program at the Mirror Lab. She didn't have to do or say anything - it seems as though all this was set up well in advance for this event. But it did occur under her watchful eye!
After the official portrait, it was cake time! After a quick frame of the main cake, some of the DKIST staff got the job cutting and serving. It was fun wandering around chatting it up with folks I've not seen in a while, folks I used to work with, and meet a couple new ones. After working at the Mirror Lab for 25 years, the main lab here seemed small, but they have certainly found their niche, finishing both this mirror and the 4.3 meter Discovery Channel Telescope primary a few years back.
Being that the event was late in the day, there wasn't much going on in the lab, but as a partial demo, a few Mirror Lab staffers who have been lent to Optical Sciences for a few months were running on a large secondary mirror. At left, Sam is watching over the swing-arm polisher working on the convex aspheric of the TAO secondary.
I went on an amble over towards the DKIST primary and took a closer look at the mirror. The Zerodur mirror surface seems to have a higher reflectivity than the E6 mirrors of the Mirror Lab, but more likely, the darker glass-ceramic makes the reflection look brighter. Anyway, I always like getting down at near-grazing angles and examining the multiple reflections off the surface. At right I can spot reliably 5 reflections and reflections of reflections, easiest seen in the "block A" at left.
And, of course, knowing me, the edge of the DKIST primary is a perfect place for a 3D stereo image! Grab the red-blue anaglyph glasses and you can see the 3D effect using a pair of images I combined in Photoshop.
Another great photo-op was part of the test system that measures the shape of the telescope mirror. Similar to the big off-axis mirrors we're making at the Mirror Lab for the Giant Magellan Telescope, a fold sphere up in the test tower is used for folding the beam and used to make the highly astigmatic mirror look more like a sphere to facilitate testing with an interferometer. And similar to the fold sphere in our Mirror Lab test tower, the center of curvature (CC) is located down near ground level. While there was an actual interferometer located at the CC, by holding my camera a foot to the side, and me standing a foot to the other side, I could see my camera in the fold sphere, thus the camera could see me! Shown at right is the view the camera saw. Unfortunately, I was inverted (I've already forgotten if the camera was above or below the CC, so the orientation could be erect or inverted), so I rotated the image 180 degrees in photoshop so you wouldn't have to look at me upside down!
I was looking for the selfie taken in the Mirror Lab's fold sphere, and found that it has never been on the blog! Amazing! I've used it often in my presentations about the Mirror Lab and our projects there, so am showing it here for a comparison to the above. I feel like the Great and Powerful Wizard of Oz gazing down at the Lab in this shot! The fold sphere is considerably larger than the one at Optical Sciences, in fact the Mirror Lab version is nearly as big as DKIST, but mounted much higher in the tower. Anyway, now you've seen them both! It's like I work at the carnival and get to play with the fun-house mirrors every day!
UPDATE! Since the party earlier in the week, Jeff Kinglsey forwarded everyone on the invitation list a copy of Frank's excellent portrait. Don't bother looking for me - I got an invite, though my contribution was minimal and didn't line up. I just came for snacks! Anyway, thanks to Jeff and photographer Frank, I received and forward the official portrait (reduced to fit blog rules)!