Category: Hardware

MagAO-X Engineering Run 2024B Day 2: The Gang’s All Here

Warren and I made it up the mountain without any necessary running. However, due to the leftover storms from Hurricane Helene, the ride was bumpier than usual thus less sleep than usual.

Progressively disheveled.

We didn’t want to be left out of Empanada Sunday, even though we technically didn’t arrive till Monday morning, so we managed to find a tasty new, or at least new to us, spot in the Santiago airport.

Something old, something new. Featured: Starbucks and Trib’s.

Up on the mountain, spooky clouds were a-brewing.

Is that a sky grating?

Okay they were kinda pretty. After dinner we got to work. Jay and Jared worked on telescope proposals while Warren and I staged the instrument for upgrades tomorrow. We moved PIAA hardware out of the system so Warren can install alignment motors on them and I’ll have room to install a reflective Lyot mask for LLOWFS. For unfamiliar readers, PIAA stands for Phase-induced Amplitude Apodization and is a type of coronagraph that utilizes four specially shaped lenses, two on either side of a light’s focus with a diffraction mask placed directly in the focus. This device will allow us to block out light from stars with Earth-like planets orbiting very close-by. Lyot-plane low order wavefront sensing (LLOWFS) will allow us to track lower order modes of turbulence in the atmosphere and enhance the PIAA’s function.

Only bad news of the day: The focal-plane LOWFS (FLOWFS) shutter gluement failed. Luckily, we have three jam packed days here in Chile to work on a bunch of engineering tasks in prep for our November run.

Sad. Jared didn’t like the white glue anyway.

Song of the Day:

We aren’t at a hotel in California, but an observatory motel in Chile is close enough. Hotel California, The Eagles, 1977.

MagAO-X Engineering Run 2024B Day 1: No Longer A Couple

One of the big goals for this visit to LCO was to troubleshoot a coupled pair of actuators on our precious 2040 actuator “tweeter” deformable mirror (DM). Being coupled meant that when we poked actuator 498, actuator 650 moved (not 498). Actuator 650 also moved when we poked 650. We first noticed this problem after shipping MagAO-X in March, when we ran a post-cabling function test. However, digging through our archives we found that it showed up back in November, 2023, but we just didn’t notice.

Now our tweeter is expensive. So we don’t like it when things go wrong, and it makes messing with it really stressful. But having those two actuators acting up means MagAO-X didn’t work perfectly, so we had to do what we can to fix it. We deferred it until after our March and April runs to give us time to plan and do it right.

We can all breathe a sigh of relief: with only minimal shenanigans we got it fixed. After testing various potential cabling problems, we found that a circuit board just needed to be replaced. We had a spare, popped it in, and the couple had split up and gone back to behaving normally.

And we got that done in time for Empanada Sunday:

Empanadas are just a little bit better fresh, compared to at midnight.

After lunch we got onto the next set of tasks, which included disassembling a rack shelf so we can get better airflow.

The shelf in question is actually Jay’s baby. He designed the hold-down system for the components on it. That also means he had to take it apart and put it back together.

We’re also upgrading the Instrument Control Computer (ICC) to go faster and do more stuff. We like to liquid cool our CPUs and GPUs. Normally we rig that up in Tucson, but we couldn’t get all of the components from our usual supplier in time, so we shipped what we had (and found some substitutes on Amazon!) and are doing some clean room plumbing.

An NVIDIA RTX 4090 in the middle of having a water cooling block attached to it. The shiny square in the middle is the business end.

Jay has also been leading the assembly and testing of new ICC. Other than the liquid cooling parts, it was fully working in Tucson before we took it apart to ship it down here. We’re getting it all back together.

Jay hard at work screwing ICC components to the custom rack mount.

Even after our delayed departure, we are making good time thanks to the relatively easy fix to the tweeter. I haven’t had enough running on this trip yet, so I took some time before dinner to go circle around the 100″.

Start of run, heading to the 100″ telescope which is down and left from Magellan.
The view back from the 100″. I’m surprised this came out, it was so windy I couldn’t hold my phone still.
From 1966.

MagAO-X Engineering Run 2024B Day 0: A Hero’s Journey to LCO

Let me tell you about our trip.

Jared and I were scheduled to leave on Thurs. 09/27, however our Tucson flight was delayed to the point where we would have missed our ATL-SCL connection, so we got the opportunity to rebook. Whether or not this was due to Hurricane Helene, we’re not sure. Because ATL-SCL on 09/27 left on time, more or less, despite being closer in time to peak hurricane’ing. Our original TUS-ATL flight arrived about 3 minutes before the plane to Santiago left the runway, so all in all, it was the right move to rebook.

Because we rebooked, the revised departure date was the next day, Friday 09/28. By about 9a on Friday, the flight was already delayed by 20 minutes (we thought: “here we go again”), but thankfully the delayed departure time didn’t change again…. all the way until the VP landed in TUS which (we painfully learned) shuts down the whole airport for half an hour. This new delay was coupled by the plane being overweight as well because of the unseasonably hot tarmac temperatures this late into September. So, the poor souls on standby who got onto the plane had to be escorted right back off to bring the curb weight of the plane down. After all that, we departed TUS *finally* at around 2:10p, a final delay of about 1hr 20mins. We were set to arrive at ATL by 8:15p EST at Terminal B. Our ATL–SCL flight was set to depart right at 8:55p, from Terminal… E….

This is NOT Air Force Two, but it was close to the airport, so, possibly related.
Cue the Mario star powerup music
Y’all ever see “Yes Man” with Jim Carrey? Maybe the group that practices running photography was onto something, this is pretty fun.

We ended up making it with mere seconds to Gate E14, but Delta misjudged our dedication (and ability to sprint) and automatically rebooked us to fly to Santiago the next day while we were still en route to ATL. After a few tense minutes, however, the gate agents were able to get us back on our original flight and thankfully they didn’t close the door on us as it was definitely after 8:40p by this point. After taking our seat, we left the ground a few minutes after 8:55p.

We landed at SCL without incident but about ten minutes past 7a local time. Normally not such a big deal, but because we had gotten rebooked initially, our new flight out SCL–LSC was at 9a on the dot. The line to get through customs was, of course, super long. We finally got through at 7:55a. Boarding began at 8a, so, more running…!

SCL has also moved the security checkpoint to near the LATAM check-in desks. Again, normally not such a big deal, but Jared was never given a boarding pass when we deplaned out flight from ATL, so he had to get one reprinted before we could get through security. It was 8:34a.

Boarding doors close at 8:45! and the B gates were, no joke, like a third of a mile from the security check point.

We. Just. Made it…!

After taking the transport up from La Serena (and sleeping for most of it), we were just in time for lunch and were greeted by some familiar views.

Truth be told, after all the delays and setbacks and just plain bad luck, I never thought we’d make it this far.

Remember Inglorious Basterds? The apfelstrudel scene is a certified classic.

Bonus Content

For today’s Bonus Content we were greeted by a ravenous goaty parade at sunset…! This made for many, many small “landmines” when walking down later that evening in the dark. Make sure you wipe your shoes extra good before entering your room during goat season.

Blog Rule

Short trip, simple rule. The blog writer must pick the Song of the Day from the assigned decade below:

Day 0: 1950s
Day 1: 1960s
Day 2: 1970s
Day 3: 1980s
Day 4: 1990s
Day 5: 2000s
Day 6: 2010s
Day 7(?): 2020s

Song of the Day

The song of the day is Frank Sinatra’s “Come Fly with Me”, originally released in 1958.

MAPS 2023A Day 3: MIRAC-5 has entered the chat

After some berating from @jlong, here is my inaugural post! First, an obligatory observatory picture.

The MMT at sunrise with the full moon on the horizon

The MIRAC-5 team arrived Friday, June 2nd to prepare for installation of the latest iteration of the instrument. Originally conceived in 1988 by Bill Hoffmann at the University of Arizona, MIRAC (Mid-Infrared Array Camera) is an ever-evolving mid-IR camera built for observing between 1 and 18 microns. It has a long and illustrious career of testing out mid-IR technologies, including various detectors and nulling interferometry (test bed for LBTI nulling). As the name suggests, we are on the 5th iteration after almost a 10-year dormancy period!

MIRAC was pulled out of retirement and refurbished to house a new mid-IR detector: the 2k x 2k GeoSnap-18 array manufactured by Teledyne. This GeoSnap is an engineering grade device with a wavelength cut-off of 13 microns. Designed for high-background applications this array is perfect for ground-based mid-IR astronomy! The primary features are wavelength sensitivity at H, K, L, M, and N-Bands (science-grade arrays will extend down to 0.7 microns), well depths of 1.3 million e– (twice that for science-grade), and continuous frame rates of >85 Hz without any reset or data acquisition overheads! After commissioning of MAPS and MIRAC, we plan to use these instruments to characterize exoplanet and brown dwarf atmospheres in the mid-IR, complementing the capabilities of JWST MIRI.

The GeoSnap engineering array in its storage contain. Of the full 2048 x 2048 pixels, only one quadrant is bonded with photosensitive material (HgCdTe).

Anyway, off came the PISCES camera and on went MIRAC. Comparatively, MIRAC is a bit of a beast.

U. Michigan graduate student Rory Bowens (right) and U. Arizona PI Jarron Leisenring (front left) and U. Michigan PI Michael Meyer (back left) posing next to MIRAC-5 mounted to the MAPS top box.

Upon hooking up the bazillion cables, we realized that the fiber extender used to transfer the data from the GeoSnap detector to the computer (located in an adjacent rack) wasn’t working as expected. The only solution was to keep the original (short) cables attached and strap the computer to the instrument cart on the telescope. It didn’t seem to complain about the free ride.

After bringing the detector temperature to a cool 40K, we were able to get the acquisition software working on the first try thanks to the diligent efforts of our software engineer Dennis Hart and successful implementation of the @jrmales’s rtimv visualization software.

Early image of a controlled PSF at K-Band running with a frame rate of 5 Hz. Hot pixels have not been masked out.

Throughout the evening, we successfully acquired a number of stars, co-aligned with MAPS, performing continuous PSF display at high frame rates, tested internal pupil chopping operations, measured background levels, and a whole host of other commissioning activities. While a few challenges inevitably arose, which we will address during the summer, it has been a pretty successful and rewarding “pre-commissioning” run so far!

Additional Random Photos

Sunset over Kitt Peak
MMT Primary
Michigan PI Michael Meyer

Song of the Day

The SAO phasing prototype visits MagAO

“Without phasing, there’s no real reason to build the GMT.”
-Andrew Szentgyorgyi

The biggest optical/infrared telescope in world will be the Giant Magellan Telescope, which will be built on a nearby mountain peak within sight of the Clay and Baade telescopes at Las Campanas.  The telescope will have 7 primary mirror segments and 7 adaptive secondary mirrors, similar to the Magellan AO system.

The 25 meter diameter Giant Magellan Telescope
The 25.5 meter diameter Giant Magellan Telescope

Photograph of the GMT site from the Magellan footpath.
Photograph of the GMT site from the Magellan footpath.

If we could build any optic we wanted for the primary of the GMT, we would probably build a monolithic 30 meter diameter (or larger) mirror made of a single piece of glass, with a thin face sheet and a honeycomb lightweight structure on back.  However, at the moment, the largest mirrors in the world are built in the Steward Observatory Mirror lab under the bleachers of the football stadium at the University of Arizona and are limited to a diameter of 8.4 meters.  Depending on who you ask, this 8.4 meter limit comes from either the distance between the columns underneath the stadium bleachers, or the size of an underpass on the highway leading from Tucson.

An 8.4 meter mirror being polished in the Steward Observatory mirror lab underneath the football stadium bleachers. Making mirrors larger than this will require a larger football stadium.
An 8.4 meter mirror being polished in the Steward Observatory mirror lab underneath the football stadium bleachers. Making mirrors larger than this will require a larger football stadium.

Because of this limit, the GMT is designed to take 7 of the largest mirrors that can be made and combine them to form one giant 25.5 meter primary.  For this to be possible, the seven 8.4 meter segments must be “phased” to a fraction of a wavelength.  That is to say, they must be aligned to each other so that they act as if they are one large continuous mirror.

To achieve the phasing of the GMT segments using off-axis natural guide stars, SAO and our collaborators at GMTO and Flat Wavefronts have designed a sensor that creates dispersed interference fringes using subapertures spanning the 12 segment boundaries.  Phase shifts across the segment boundaries manifest themselves as tilts in the fringes.

Segment boundary subapertures for the dispersed fringe phasing sensor.
Segment boundary subapertures for the dispersed fringe phasing sensor.

Simulated fringes from one subaperture showing 0 piston phase difference (left) and 10 microns (right).
Simulated fringes from one subaperture showing 0 piston phase difference (left) and 10 microns (right).

To test this sensor technology, SAO has built a phasing prototype that simulates 6 of the GMT segment boundaries working in conjunction with the Magellan AO system.  Our three nights at the end of the MagAO run turned out to be a success.

Six sets of fringes as seen by the SAO phasing prototype working in conjunction with the MagAO system.
Six sets of fringes as seen by the SAO phasing prototype working in conjunction with the MagAO system.

The SAO phasing prototype team. Clockwise from top left: Derek Kopon, Alan Conder, Ken McCracken, Jared Males, Laird Close, Dan Catropa, Brian McLeod, Bill Podgorski.
The SAO phasing prototype team. Clockwise from top left: Derek Kopon, Alan Conder, Ken McCracken, Jared Males, Laird Close, Dan Catropa, Brian McLeod, Bill Podgorski.

We obtained phasing data both on-axis and off-axis, with AO on and off, and at two different wavelength bands (I and J).  This data, and data that we gather during another run possibly in February, will inform the design of the GMT phasing sensor, scheduled for first light in the next decade.

Lastly, a “song of the run:”  Phazing, by Dirty South:

https://www.youtube.com/watch?v=031hzipvnTY