Multi-threaded software is hard. You get all these different processes trying to access the same place in memory, and if they do it at the same time weird things happen. We have ways to stop these “data races” with tools like “atomics” and “mutexes” (mutices? plural of mutex for mutual exclusion) — but these add a new fun bug called “deadlock” when different threads try to lock the same mutex. So I’ve been spending lots of quality time with my new third best friend GPT-Codex. We make about 20 steps forward for every step back, but it’s in the time it used to take me to take about 1 step forward. Winning.
Miles has been hard at work getting his new polarization components installed. Here we’re using a bright red laser to chase the beam path through the instrument.
Sebastiaan and Adam arrived from Leiden today. Sebastiaan is already complaining about having to do EFC.
The door to the lodge was being guarded this afternoon. In a very friendly fashion.A nice sunset from my room tonight.
The color of the day is HeNe laser red.
The song of the day is The Emptiness Machine by Linkin Park:
Welcome to the second work day of the 26A run! Today we’ll be taking a brief look at some of the polarization work I’ve been doing (because, you know, if I didn’t mention polarimetry, did I even write a blog post?)
I’m back on mountain timeOne of the weirder polarization stages at LCO.
Today I spent time managing cables for the polarimeter and for the new polarization compensator I’ll be deploying. For the half-wave plate stage outside the instrument, I worked on reducing our heat outputs by moving the AC to DC converter bricks from directly underneath our entrance port to inside the server rack. I reckon this’ll give us at least +1-2% Strehl ratio. Having all the cables managed neatly in bundles keeps our operations smoother: there’s less chance of the cables snagging, and plugging and unplugging from the server rack is logistically easier.
What’s missing from the polarimeter now?Clean cable management
Inside the instrument, I’ve gotten the control electronics routed into the top bench for the polarization compensator–tomorrow I’ll be installing it!
Control electronics in the black boxThe dual QWP polarization compensator
Additionally, Jay, Eden, and Jared finished the glycol plumbing! The hoses, manifolds, and devices were backflushed to remove gunk and, eventually, the entire cooling loop was up and running!
Backflushing the gunkThe Gunk^TMOut with the old, in with the newClean Connectors lead to Constant CoolingTroubleshooting
Following the successful plumbing, the remainder of the cables between the server and the instrument were connected, followed by a system check for the deformable mirrors and motion stages. The loop has been closed, so we’re ready to proceed with the remaining engineering tasks for this run.
They’re so good at cabling I just stayed in the corner with the cleaning wipes
Color of the Day
So, today I accidentally walked out of the clean room with my shoe covers still on. Oops. Miraculously, so did Eden at the end of the day. In honor of our buffonery, I nominate clean room shoe cover blue (Pantone 14-4530 TN BLUEFISH) as the color of the day.
Today, we’re officially officials of the official pre-observing engineering duties for MagAO-X officials. We officially go on-sky on March 25 so we’ve got a jam-packed list of things to knock out before then. Since we arrived on the mountain without delays yesterday, we elected to dedicate the rest of the day/night Saturday for healing after the long trip, which was much appreciated. Today, after breakfast, Jared, Eden, and I promptly headed back to the cleanroom to get to work.
quick OOOTD fit check before some hardcore clean room activities
The first step was to de-cable the electronics rack and instrument which Eden and I made quick work of…! This is because we eventually needed to push the rack and instrument into the clean room such that the real instrumentation work can begin ASAP.
After separating the components, we then addressed the screw jacks that allow us to raise and lower the instrument for precision leveling and telescope alignment on the platform. You see, we were losing screw thread integrity across several bolts very quickly due to (we suspect) galling. To fix this issue, we installed new black oxide screws for better compatibility with the stainless threads. Will this solve our screw jack issues? Time will tell.
Oh yeah, and since today was Sunday…
After empanada lunch, we were soon joined by our resident expert in polarimetry who was v quick and eager to get to work.
One of the big ticket items to address today was a mysterious and yet sudden increase in the measured humidity in the air that feed the DM enclosures within the instrument. Since humidity levels can invite corrosion (hence damage) in our MEMS DMs, it’s important that we investigated the quality of the air coming out of the clean room air supply. However, when we started scrutinizing the various components of the air feed system, we noticed exhausted desiccant and a compressed air drier full of water. Not great, but the drier can be drained and the desiccant replaced. However, when we drained the drier and re-connected the air tube back to the supply it filled back up almost immediately…! In fact, we disconnected the air hose at an intermediate point while it was still connected to the supply at the back wall and we had a full-on mini fire hose in our hands…!! This could have obviously led to a catastrophe of epic proportions, but disturbingly didn’t. It’s clear that our desiccant can work miracles or something.
This little air hose was legit hosing down the walls of the clean room with the amount of water coming out of it
Obviously we’re a bit dead in the water while this issue gets addressed as we can’t operate the DMs or float the table at this point. To cap off the work day, we worked on installing liquid cooling for the Kinetix cameras in the instrument in an effort to address bench seeing caused by thermal gradients. This way, the heat generated by these fast-running cameras will get flushed out rather efficiently and released far from the telescope. This portion of the work day involved lots and lots of hosing, (back)flushing, and glycol which is always fun.
glycol hoses can spout like a whalekeep your friends closethankful for gravity
As such, the color of the day is:
really leak-proof glycol pink!
We ended the work day with final install of all our custom-made glycol hosing for the Kinetix cameras for FLOWFS and LLOWFS. After clamping it all down, we intitiated a leak test by pressurizing the (empty) glycol tubing with air to 12 PSI with the intent to see if the pressure decreases overnight. If it doesn’t, then we’re good to refill the instrument glycol system and move onto the next project! We’ll check on it in the morning, so stay tuned for tomorrow’s post to hear about the results.
Song of the Day
If arts and crafts with glycol tubing was a guitar riff…
Flying out on Friday the 13th comes with some ominous portents. Thankfully, we only seemed to be hexed with suboptimal seat assignments and the briefest of turbulence. As of writing the early crew has made it safely to LCO, tucked in and ready to start fresh tomorrow morning.
Proof of life.
For all those traveling later, know that there are some tasty cafes right outside the B terminal now. Post security no longer contains the only sustenance offerings. The Starbucks by luggage check-in has, in fact, even kept up the important renaming ritual.
Jerry, Jen, and Iren – now caffeinated.
The welcoming committee to LCO was packed. Just as we turned off the highway a large wild horse heard greeted us. We ran into even more at the top of the mountain.
White horse in line.Sharing the road.Not sharing the road.
A family of Burros we’ve never seen before met us in the basin. One family was very bright white too! The more local mountain burros looked to have welcomed some new members recently as well.
Albino and family. Fluffball and family.
After a quick dinner (thank you chefs for staying open for us) Jay and I took a walk to double check we had our essentials in play. It looks like we’re all ready for tomorrow!
Cleanroom vizzy. MagAO-X in the cleanroom room.
The mythical white horse, the albino burro, and auspicious vizzy all must mean something. I’m sure we’ll be able to interpret these portents by the end of the run.
Color of the day: Prophetic Albino Burro White
Blog Rules: Color of the day
Every blog should include a color of the day. (Interpretative, but bonus points if a swatch of the color is included)
The color should be a reference to a blog occurrence or the song of the day
There shall be a song of the day, linked, with song title and artist in the description. (Sometimes the link dies, and the description helps us find it later.)
This is inspired by my love of dialed the color memorization game, and the fact you can color swatch your own photos.
Song of the Day:
You know, I just see horses and I know there’s a way.
PASADENA, CALIFORNIA – Every fewyears, an eclectic group of scientists and engineers gathers in a scenic location to discuss the minutiae that come with taking pictures of really dim things next to really bright things. The Spirit of Lyot conference is named for one Bernard Lyot, a French astronomer known for inventing an instrument to observe the Sun’s corona without having to wait around for a solar eclipse.
Early on in the conference, one of the organizers clarified that this gathering was about Lyot’s “spirit” meaning legacy, not his literal ghost. Now, we here at MagAO-X most certainly honor Lyot’s high-contrast legacy by observing binaries, disks, and planets. But, it’s also worth mentioning that if there’s one thing optical engineers are haunted by, it’s ghosts.
For those unfamiliar, a ghost is a technical term used in optics to describe an unwanted reflection. Put simply, this could be anything from seeing your own face reflected back at you when you’re trying to look out the window to having your laser bounce back off lenses it’s supposed to transmit through. Optical ghosts are pernicious little things; they can cause unwanted spots on your camera or even render your g-band filter practically useless. They’re difficult to get rid of, but pretty easy to introduce. So, in order to understand Dr. Bernard Lyot’s true opinion of MagAO-X’s contribution to his conference, I have taken it upon myself to summon his (optical) ghost this Friday the 13th and ask about his approval or disapproval on some things we did last week.
whether or not this is *technically* a ghost is up for debate, but I certainly consider seeing myself in my laptop screen as an “unwanted reflection”
APPROVED: A Plethora of Posters
From graduate students to postdocs, Lyot agrees we kept MagAO-X well-represented at both poster sessions throughout the week. In no particular order:
And this isn’t even all of them!
DISAPPROVED: Yassification
“Mais c’est quoi ça??”
-the spirit of Lyot, upon being shown the AI-yassified versions of our poster presentation photos
Out of respect for him (and Hayao Miyazaki), I will not include them here.
APPROVED: Talks on Talks on Talks
During the instrumentation sessions, we found ourselves well-represented. On Thursday, Jared talked about next-generation HCI with GMagAO-X, Laird got the chance to talk about WISPIT 2b, and Miles did some polarimetry show-and-tell about some disk observations. We also got to hear talks from Rico, Louis, and Adam, members of Sebastiaan’s group in Leiden, and Saraswathi, a postdoc from UASAL.
On Friday, Josh told us about the highs and lows of building the Self-Coherent Camera on the CACTI testbed, and Sebastiaan closed out the MagAO-X talks by giving an overview of the many, many emerging technologies in our field.
DISAPPROVED: Upside-down Glasses
A couple of us took the chance to tour NASA JPL, which got a seal of approval from both the four of us and the Spirit of Lyot. However, he (rightfully) poked fun at the picture of my failure to understand how 3D glasses work.
our girl voyagerooooh ahhhhJay’s kryptonite around every corner
APPROVED: Family Dinner
The conference dinner was held at Caltech’s Athenaeum. Not everyone could make it (places to be, e.g. Target), so we made sure to get a family photo beforehand.
say cheese!
DISAPPROVED: Etiquette Ignorance
I have no visual to illustrate this, but let’s just say Parker and I exchanged a very panicked glance when we saw the number of utensils we were expected to use at this dinner. Luckily we had a couple of former Navy Nukes to teach us the difference between a salad fork and a regular one.
APPROVED: Astro-tourism
If you believe his Wikipedia page, Lyot was also an avid mountaineer and even trekked to the Pic du Midi observatory when it was only accessible by cross-country ski. Naturally, his spirit approved of the group that stayed a little bit longer to make the journey up Mount Wilson.
c = 3×10^8 m/s
DISAPPROVED: A Seat-cushion Mishap
Ever wondered why, during the standard aircraft safety briefing, they tell you to ask for assistance if you lose an electronic device in your seat? Well, I no longer wonder that. Let’s just say the pilot himself came out to help at one point. The important part is that Josh and his earbud were reunited, safe and sound.
APPROVED: Song of the Day
In the spirit of Lyot: a French song that talks about both the Sun and finding something that exists, but was hiding:
