MAPS – Page 7 – Extreme Wavefront Control Lab

MAPS May 2024A Day 1-Night 1: Installation and Alignment

The first two nights of this run are for MIRAC (PI: Leisenring), while the last 4 are for AO (PI: Morzinski). Therefore I decided this was my chance to come up in the morning to see the installation of MAPS. See, usually I try and sleep in on the morning before a MAPS run, to help me switch to a night schedule. But instead today I got up in the morning as usual, headed up to MMT, and was able to observe the installation of the Top Box and ASM with a full MMTO crew as well as Dan and Ruby from MAPS. This is important to me because we’ve talked a lot about the installation procedure and whether it can be made more repeatable, but I hadn’t actually seen the full procedure yet. Now I have a much better picture of the process and thoughts about repeatability.

Installing the Top Box to the Cass port of the MMT.

So here’s what I saw. When the Top Box is installed there are 4 feet on the lift that can be independently adjusted. However, the actual measurement of how parallel the Top Box plate is to the Cass plate is through hand-held measuring tapes. There are 2 pins that help guide the Top Box up. And in the end the plates were flush. But I was wondering whether there could be any skew on one side or another.

Installing the Top Box: Measuring the gap on all sides to make sure it’s going on straight.

The ASM installation is complex. The ASM is mounted to the hexapod. This is done while the former is hanging from the crane and the latter is supported on a bouncy stand — so could these be misaligned? But then the screws are gronked on until the plates are flush, except for a gap covering about 20deg on one side where the ASM plate is warped, of about 4 thou. Then the hexapod is mounted to the hub. It’s behind a flange, but the 2 pins keep it aligned, one of them is diamond shaped to control angle, and then the screws are gronked on until tight so we assume it is flush too.

Measuring the gap over about a 20-degree wedge due to a slightly twisted ASM mounting plate. It appears to be repeatable, plus all the bolts are flush and the rest of the mounting plates are flush with no gap all the way around.

Craning the ASM+Hexapod structure up to mount it to the Hub.

Also Dan and Ruby connected the rack and all our other cables:

Connecting the cables in the elecronics rack on the third floor.

Then tonight was supposed to be a MIRAC night but they had a chiller problem and weren’t cold enough, so instead we decided to try AO.

Except instead it still took over half the night to complete set-up and alignment. So we continue to explore how to improve these procedures.

Even though this is the MAPS run not the MagAO-X run, I’ll stick with the MagAO-X blog rules for this run. Therefore, the best 15 minutes of the day were seeing the ASM mount to the Hexapod and then the whole assembly mount to the Hub. I have to admit I’ve never quite pictured it correctly when we talk about in our off-mountain meetings, so this helped me visualize what’s happening very well!

Song of the Day/Night: “…Baby One More Time” by Britney Spears (1998)

MAPS/MIRAC Mar. 2024A Nights 5-6: Windy cloudy graupel

Night 5 started out with Manny and Dan cooking a delicious pancake/egg/sausage/bacon breakfast for the whole crew! Dan came up just to help Manny out, and a great time was had by all.

Post-breakfast, pre-sunset game of pool.

At sunset we were closed due to high winds, then the thick clouds rolled in. It looked like the wind was dropping, but actually the anemometer must have frozen because the winds were still very high in real life!

This picture is supposed to illustrate high winds and building-up clouds at sunset on Night 5. It’s hard to depict wind in a still jpeg though. But those pine tree branches were really blowing!

Around the halfway point of the night it started to graupel, and there were thunderstorms 30-50 miles away. So we never opened, and we put the telescope and instruments into lightning shutdown mode. The MAPS and MIRAC teams waited out the weather until around 3am when we and our TO agreed that the weather seemed to be behaving according to the forecast, and the forecast was calling for more snow and wind the next day and night. Therefore, towards the end of night 5 we decided to call off night 6, and the MAPS/MIRAC teams fled the summit and the snow for the balmy Tucson rain.

Some of us left around dawn, others slept a bit longer, but here was my dawn between Nights 5-6:

The song of the nights is the sound of wind-driven graupel striking the side of the metal dome.

MAPS/MIRAC Mar. 2024A Night 4: We fixed it!

Despite the partly cloudy night, we fixed several issues and made a lot of progress!

MIRAC pupil alignment — an errant detent was corrected and the ellipsoidal mirror internal to MIRAC solved the mystery of co-aligning telescope, AO, + MIRAC pupils!

AO camera lens loop — finally got it calibrated, and working beautifully on-sky!

AO calibrations — got a successful 20 modes loop, and discovered that a better SNR is needed for higher-order loops. SNR can be increased by raising the amplitude/stroke (but need to test where the linear range ends), and/or by increasing the number of iterations (we went from 500 to 2000). We also received wisdom on inverting the calibrations and making our own masks.

However, the partially-cloudy conditions made it impossible to actually take a long-enough running calibration to raise the SNR enough to go to 100 modes. So that awaits another night.

The song of the night is the sound of silence.

MAPS/MIRAC Mar. 2024A Night 3: Closed loop calibrations

A much better night!

So we were joined by our CACAO friends in Chile and Hawaii to take AO calibrations:

But we learned the camera lens loop was still a hold up so we spent a good long while trying to get it working as well:

The song of the night is the sound of a mouse being trapped (in a live trap) in the kitchen. The sample track is the sound of Rory when he discovered said mouse in the sink (yesterday).

MAPS/MIRAC Mar. 2024A Night 2: Tunisian crochet

Tonight started cloudy and even with a little precipitation! (Which we just can’t bring ourselves to actually complain about, being children of the drought-stricket desert southwest.)

Image description: A closed telescope dome in front of thick clouds on a rocky mountain peak, with snow amongst the rocks and fluffy-looking pine trees in the foreground.

Image decription: Same closed telescope dome from a different angle, with thick clouds in the sky, and the red light of dusk making the mountain ridge redden as well.

So it was time to learn some Tunisian crochet, courtesy of a book authored by MAPS and CAAO colleague Lori Harrison: Exploring Tunisian Crochet: All the Basics Plus Stitches and Techniques to Take Your Crochet to the Next Level; 20 Beautiful Wraps, Scarves, and More.

While we were clouded out, I called in to the MagAO-X run to eavesdrop for a little while on the MagAO-X AO GUIs:

Finally the clouds cleared up around 11pm and we went on sky! Only to have trouble finding our stars. We even pointed at the moon (which is 31 arcmin in diameter) and we could find that! But we tried to focus on the limb and just weren’t able to get the adjustments we needed to sharpen it up. This was all most likely due to the primary mirror cell throwing an error with a garbled measurement that was causing an unknown piston and tip/tilt that we just weren’t able to take out with pointing the mount and focusing the hexapod. We do wish our cameras had a larger field of view to help with finding stars when there’s a trouble issue like this, but ultimately it seemed we didn’t even have the range to take it out.

Meanwhile MIRAC was still working on adjusting its pupil alignment, which was actually a fine thing to do when all you can see is the sky (but no stars). This time Manny and Rory went up and turned one of the screws on the bellows, with little effect. We also tried rotating the instrument rotator, and were gratified to see it did indeed rotate the one bright spider we could see, but still did not help to center the telescope pupil with the MIRAC pupil. Ultimately we had to call it a night around 2am.

The song of the night is the sound of water dripping from the trees.