Confronting Change

In earlier posts, I’ve discussed working with the Hydra spectrograph on the WIYN Telescope at Kitt Peak National Observatory. It’s a piece of instrumentation that allows astronomers to observe up to 90 objects simultaneously during one telescope pointing. The WIYN telescope can see one square degree of the sky at a time. Hydra has a set of optical “buttons” which can be placed on a metal plate at the position where an object will be in the field of view. These buttons send data to the spectrograph two floors below via fiber optic lines. The device that places these buttons is a robot, which resembles the claw from crane machine. It picks up each button from a parked position and puts it where it belongs.

Sticker on Hydra’s side

This type of multi-object spectrograph is somewhat common now, but Hydra was one of the first of these types of spectrographs built in the early 1990s. In fact, the instrument is older than the WIYN telescope and I helped to commission the instrument in its first version at the Mayall 4-meter. Precision machines like the Hydra gripper suffer a lot of wear and tear in 30 years, so a little over a year ago, Hydra began an upgrade process. The engineers worked with Prod Design and Analysis in El Paso, Texas to upgrade the gripper with new technology. The folks at Prod were struck by how much the gripper resembled a crane machine’s claw and added the sticker you see in this first photo.

Hydra Control Rack

As you might imagine, I’ve become quite familiar with Hydra, working with it off and on for almost thirty years. However, making major changes to the instrument meant learning new procedures. The original Hydra gripper was an analog device that “knew” where buttons were by counting steps using a device called an encoder and then remembering those steps to go back and pick the button up again. If there was some electrical noise or a mechanical problem that caused the count to be less precise, it could miss picking up the button. The upgraded Hydra also uses encoder counts, but it has added new programmable logic controllers and video analysis. It goes to the button, takes a picture, analyzes that pictures and then adjusts it’s position, if needed, to get the button. All this new logic has meant that we have a new control cabinet in the telescope to house electronics. The hope is that this will make positioning more accurate. However, it has meant learning new ways to monitor the process of the gripper at work and recovering the gripper if problems occurred.

This past week was one of the first times I’ve had to use the upgraded Hydra without one of the engineers on hand in case problems occurred. I made sure to review the manual, because it had been several months since my introduction to the upgrades and I reviewed the troubleshooting procedures. The first night of observing started out quite smooth. We had four field setups without any problem whatsoever. Then on the fifth field configuration, a heart-stopping problem occurred. The Hydra control program crashed while the gripper was carrying a button to a new position. Of course, these buttons and their attached fibers are all very delicate and if Hydra forgets the button’s position, there’s a risk that the attached fibers could get tangled. This could prove to be a very expensive problem.

In the old days, a problem like this automatically meant going into the dome, which is a cold proposition on a winter night! Then with a long stick , carefully reaching into the instrument and releasing the button from the gripper jaws, which allow you to open the instrument. After that, you’d have to manually place this fragile, optically sensitive button and fiber back into its stow position. In short, it’s a delicate procedure to do when you’re cold and on a lift in a dark dome!

The new Hydra Handpaddle

Now we have a handpaddle, which lets us talk to the gripper directly. I went to the Troubleshooting guide, refreshed my memory and followed the instructions. For the most part they worked. I was able to control the gripper and set the button down in a controlled way. Unfortunately, we’re still working out some bugs, so I still had to open Hydra and check the button’s real position, but it was a much quicker, safer operation.

Confronting change in procedures that had grown familiar and routine was definitely scary and a little challenging. The things that helped me manage my discomfort were focusing on the familiar parts of the routine, reviewing the new procedures before starting work, and then when a problem did happen, I took a deep breath and used the instructions and my experience to solve the problem the best I could. This past week, the upgraded Hydra moved from a machine that presented me with a little anxiety to a machine I look forward to understanding better.

Breaking Records

It occurred to me it’s been a while since I’ve shared a behind-the-scenes look at my work at Kitt Peak National Observatory. Now that the DESI spectrograph is on the Mayall Telescope and the NEID spectrograph is on the WIYN Telescope, we’ve fallen into a fairly regular routine where, most nights, I check in with the observing team at 4pm via video chat, then go to the control room where I’ll eat dinner, open the telescope and start observing through the night. We wrap up as the sun starts lightening the sky in the morning. Targets for the night are predetermined before observing begins for the night. Once observing begins, much of my job is watching that the telescope doesn’t try to move to a position where it physically can’t and I’m the first line of defense in case the telescope or instrument malfunctions. I also watch the weather to make sure rain, wind, or snow don’t damage the telescope.

A slice through the 3D map of galaxies from the first few months of the Dark Energy Spectroscopic Instrument (DESI). The Earth is at the center, with the furthest galaxies plotted at distances of 10 billion light years. Each point represents one galaxy. This version of the DESI map shows a subset of 400,000 of the 35 million galaxies that will be in the final map. Image courtesy NOIRLab.

Before the COVID-19 pandemic, we expected that both the telescope operator and lead observer for the night would be working in the same room, possibly with some support scientists. As it turns out, I wrote a post recently describing how these plans had to change so we could operate safely in these times. As things currently stand, I work in a control room alone and coordinate with the rest of the team via video conference. You can read that post here: https://www.desi.lbl.gov/2021/11/17/social-distancing-while-mapping-the-universe/

All this steady plugging away, observing the sky night after night with DESI is paying off. It was just announced that after just seven months of operation, DESI has already surpassed 7.5 million galaxies mapped, which means it has already generated the largest 3D map of the universe to date. And we’ve only completed about 10 percent of the survey. When we’re done, we expect to have mapped over 35 million galaxies. The picture with the post is a slice of the map so far. The map is presented such that Earth is at the center. Each point on the map is a galaxy. I encourage you to take a look at the press release about the DESI results so far. It’s at: https://noirlab.edu/public/news/noirlab2203/

One of my favorite images at the press release is an interactive image where you can look the map above and compare it to all the data from the Sloan Digital Sky Survey in New Mexico. Sloan has been an on-going, ground-breaking project in its own right. I was fortunate enough to be on hand when that telescope was dedicated and the survey began. At the time, I worked as an engineer for a 1-meter telescope just a few yards away from the Sloan at Apache Point Observatory. I think it’s fair to say that DESI would not have been able to achieve what it has so far if Sloan hadn’t paved the way.

As it turns out, DESI’s value isn’t limited to creating a big map of the universe. Yes, that’s important and hopefully it’ll give astronomers clues about how the universe is expanding and how that may be related to this thing called dark energy. However, DESI is also creating a giant database of all these spectra that researchers will be able to use for years to come to understand more about the different types of galaxies and quasars we’re observing along the way.

On a good night up here, everything seems quiet and routine, which doesn’t give me a lot to share here, but it is producing lots of data and expanding our knowledge of the universe. Of course, routine nights also give me a chance to ponder the universe and continue to inspire me. As always, you can find links to my books and stories at http://www.davidleesummers.com

TusCon 48

This coming weekend, I will be one of the programming participants at TusCon 48, which will be held at the Sheraton Tucson Hotel and Suites in Tucson, Arizona from November 12-14, 2021. The author guest of honor will be New York Times bestselling author Jennifer Ashley. The artist guest of honor will be Jill Bauman, who has illustrated hundreds of works including those by writers such as Harlan Ellison, Stephen King, Peter Straub, and Lilian Jackson Braun. The fan guest of honor will be Doreen Webbert. The toastmaster will be Bram Stoker Award-winning author Weston Ochse. you can find more information about the convention at https://tusconscificon.com

Hadrosaur Productions will have a table in the dealer’s room, where we will feature some of my recently updated titles such as The Pirates of Sufiro, Children of the Old Stars, and Heirs of the New Earth. We will also have books by other authors on hand such as Exchange Students edited by Sheila Hartney, Hybrid by Greg Ballan, and Upstart Mystique by Don Braden. I’m excited to note that Don Braden will be on hand for TusCon. If you’re there, be sure to buy a copy of his novel and ask him to sign it for you!

My schedule for TusCon is as follows:

Friday, November 12

6:00pm to 7:00pm in Panel Room 1. Are Canonical Stories Better than Non-Canon. We have many kinds of expanded stories. Some of them are part of canon. Some are not. Which is better? Is there a better? On the panel with me are Linda D Addison, Catherine Wells, and Marty Ketola.

Saturday, November 13

9:00am to 10:00am in the Ballroom. Solving your Heroes Problems Well. Putting heroes in danger is almost the definition of what authors do, but how do you get them out of the danger realistically but not to easily? On the panel with me are Catherine Wells, Bruce Davis, and Cynthia Ward.

12:00pm to 1:00pm in the Autographing Area. Autograph Signing. I will be available to sign autographs throughout the convention whenever I’m at my dealer’s table, but for this hour, I’ll hang out at the autographing table.

1:00pm to 2:00pm in Panel Room 2. Hunting for Planets from Kitt Peak. A look at how we’re hunting for exoplanets at Kitt Peak National Observatory using the NEID spectrograph along with a discussion of some cool exoplanet results.

If you’ll be in Tucson this coming weekend, I hope to see you at TusCon. Please note, the organizers do require proof of COVID-19 vaccination for admission and masks will be required throughout the weekend.

Summer Shutdown 2021

I returned to work on site at Kitt Peak National Observatory in November 2020. Social distancing regulations were put in place along with several other protocols to minimize the risk of COVID-19 infection. In that time, we’ve been making great strides commissioning the DESI spectrograph and starting it’s five-year survey, which is intended to result in the most comprehensive 3D map of the universe yet made. The instrument is already getting results. For those who don’t recall earlier posts about DESI, it has 5000 optical fibers mounted at the prime focus of the Mayall 4-meter telescope. Each fiber can be positioned to align precisely with an object on the sky. The fibers run to a spectrograph where the light is analyzed and redshifts of distant objects such as galaxies and quasars can be measured. The following image shows how much sky DESI gets in one pointing. It shows the nearby Andromeda Galaxy taking up much of the field, but as an example, you see that one fiber has landed on a distant quasar. It’s spectrum is displayed in the inset box. Each of the pizza-slice segments represents the 500 fibers in one petal of the DESI instrument.

The disk of the Andromeda Galaxy (M31), which spans more than 3 degrees across the sky, is targeted by a single DESI pointing, represented by the large circular overlay. The smaller circles within this overlay represent the regions accessible to each of the 5000 DESI robotic fiber positioners. In this sample, the 5000 spectra that were simultaneously collected by DESI include not only stars within the Andromeda Galaxy, but also distant galaxies and quasars. The example DESI spectrum that overlays this image is of a distant quasar that is 11 billion years old. Credit: DESI collaboration/DESI Legacy Imaging Surveys/LBNL/DOE & KPNO/CTIO/NOIRLab/NSF/AURA/unWISE

Summer in Arizona is monsoon season. In short, we get a lot of rain. Clear skies can be few and far between. As a result, this is the time of year engineers often choose to shut down the telescopes to do maintenance and make modifications. The DESI instrument has been performing well, but that doesn’t mean it can’t be improved. The fibers in each of those pizza-slice shapes are aligned by a system called the “Command Action Network” or CAN-Bus for short. It was determined that the CAN-Bus system in DESI could be improved. To do this, each petal has to be removed from the Mayall’s prime focus and placed in an area where it can be worked on. We’re able to do this work this summer because of the availability of COVID vaccines. We do take care to practice social distancing where possible and, especially in the wake of the Delta variant’s rise, we’re staying masked throughout the day. This next photo shows DESI with four of the petals removed.

DESI opened up. The red device in the foreground is used to carefully extract the petals.

The trickiest part of this operation is that the DESI petals are all attached by several yards of fiber optic cable to the spectrographs two stories below. When we remove the petals, we don’t want to torque or strain those cables too much. The petals are lifted down and placed on the floor beside the telescope. Once there, they’re placed into clean tents where they’re worked on. Here we see two members of the DESI team diligently working on the CAN-Bus electronics behind the fiber positioners.

Working on the petals. The fiber optic cables come out of the tent, run along the top and then over the rail to the spectrographs below.

Finally when all the new electronics are installed, the petals have to be tested. Among other things, we need to make sure we didn’t break any of the fibers as we handled the petals. DESI is designed to be able to shine light from the spectrograph up through the fibers. We call these “back illuminators” and a camera mounted just below the telescope’s primary mirror can take an image of the back illuminated fibers to see what position they’re in. Here we see the petal out of the telescope with the back illuminators turned on.

DESI’S fibers glowing a friendly blue, telling us all is well after the work has been completed.

Once the upgrades are completed, the petals are reattached to the telescope. This is a big collaborative effort involving many people from around the country and around the world. Once it’s done, we should have made what was already a powerful machine designed to answer questions about dark energy into an even more powerful machine.

TusCon 46

Next weekend, I’m delighted to return to TusCon in Tucson, Arizona as a panelist and book dealer. This year, TusCon’s author guest of honor is Jonathan Mayberry. The artist guest of honor is the very talented Chaz Kemp, whose work I’m proud to display in my home. The toastmaster is Weston Ochse. The convention will be held at the Sheraton Tucson Hotel and Suites at 5151 Grant Road. You can get all the details by visiting http://tusconscificon.com.

My schedule at the convention is as follows:

Friday, November 8

Changing Channels: How/Why Do Authors Change Genre? Panel Room 1. 6:00 pm – 7:00 pm. Given how much publishers want writers to stay in their box why deal with the arguments? Are the publishers right? Will your fans follow? Are you just changing things up for fun? On the panel with me are Frankie Robertson, Jill Knowles, Paul Clinco and Thomas Watson

Meet the Guests. Ballroom. 7:00 pm – 9:00 pm. Hobnob and schmooze with our guests, enjoy the cash bar, and laugh it up with Toastmaster Weston Ochse.

Saturday, November 9

What I Know Now, What I Wish I Knew Then: A Writer’s Journey. Panel Room 1. 9:00 am – 10:00 am. Successful writers talk about what they`ve learned along the way. On the panel with me are Eric T. Knight, Gloria McMillan, Ross Lampert

Autograph Session. Autograph Area. 3:00 pm – 4:00 pm. Come get autographs from your favorite folks. Some are even probably selling stuff. Not only can you get my autograph, you can get autographs from Ross Lampert, Tabitha Bradley, and Thomas Watson as well!

Surveying the Universe – Our Five-Year Mission to Create a 3D Map of the Universe. Panel Room 2. 5:00 pm – 6:00 pm. Did you know Kitt Peak was mapping the universe? Come to this presentation to find out about awesome stuff in Tucson’s own backyard.

Sunday, November 10

Southwest Folklore, Urban Legends, and Paranormal Encounters. Panel Room 1. 10:00 am – 11:00 am. A lot of cultures meet here. With a lot of history. How have these combined to build our legends and ghosts? On the panel with me are Chris R. Chavez, Liz Danforth, and Weston Ochse.

Making Light of the Dark: Humor in Horror. Ballroom. 2:00 pm – 3:00 pm. Terror seems like it should preclude amusement. What makes us laugh does not seem like it should be capable of also making us scream. But while seemingly attempting to achieve opposite results, comedy and horror are intricately linked. While playing on different emotions, both are devised to generate specific and extreme reactions from their audiences. Two sides of the same coin, humor and horror are strong on their own, but working together, they can create a marriage of unexpected twists and turns. This panel will explore the rise of the horror comedy and address why the combination works and why it sometimes fails. On the panel with me are James Sabata, William Herr, Wolf Forrest, and K.S. Merbeth.

When I’m not at one of these events, I’ll be at the Hadrosaur Productions table in the dealer’s room. Please come by and shop our fantastic selection of books and I’ll be happy to talk to you more about any of the panel topics, or things that don’t even relate to the panels. Also, be sure to ask about the annual party that we thrown in conjunction with Massoglia Books at TusCon. It’s always a great event and I hear there will be cake.

MileHiCon 51

Next weekend, I’ll be a participating author at MileHiCon 51, which will be held at the Hyatt Regency Tech Center in Denver, Colorado. The guests of honor are authors Angela Roquet and Marie Brennan and artist Elizabeth Leggett. The toastmaster is author Carol Berg. You can get more details at the convention’s website: https://milehicon.org. A selection of my books will be available in the Vendor Hall at the table run by Who Else Books. My schedule is below.

Friday, October 18

9-10pm – Mesa Verde B – Group Reading and Discussion: After Dark. Authors James Van Pelt, J.T. Evans, Joseph Paul Haines, and Shannon Lawrence will join me to read selections from and discuss our horror fiction.

Saturday, October 19

10-11am – Mesa Verde C – Put a Gear On It. I will join Meghan Bethards, J. Campbell, Craig Griswold, and Rob Rice to discuss steampunk fiction.

Noon-1pm – Grand Mesa Ballroom – We Named the Dog Indiana. I join Carol Berg, J. Bigelow, V. Calisto, and James Van Pelt to discuss the whys and wherefores of naming characters.

1-2pm – Mesa Verde A – Year in Science. I’ll discuss the topic with J. Campbell, Dan Dvorkin, Courtney Willis, and Ka Chun Yu.

3-4pm – Wind River B – From Kitt Peak to the Universe. I’ll introduce the new DESI spectrograph that’s been installed at Kitt Peak National Observatory and how it will be used to make a three-dimensional map of the northern sky.

4-5pm – Grand Mesa Ballroom – Mass Autographing. I’ll be available during the mass autographing to sign any books you bring along.

Sunday, October 20

3-4pm – Wind River B – Patreon, Kofi, Drip, and other Alternate Funding Sources. I discuss the topic with R. Hayes, Patrick Hester, and Stant Litore.


If you’re in Denver, Colorado next weekend, I hope I’ll see you at MileHiCon!

Cable Wrangling

In previous posts about the DESI spectrograph being installed at Kitt Peak’s Mayall 4-meter telescope, I’ve focused on the 5000 robotic positioners at the telescope’s focal plane, which is up at the top of the telescope, and the ten spectrographs located in a climate controlled room at the telescope’s base. However, I haven’t talked a lot about how the light from the 5000 positioners gets down to those spectrographs. The light travels along optical fibers that run from the telescope’s focal plane down to the room with the spectrographs. The whole distance is roughly 40-meters (or a little less than the length of half a football field).

In the photo to the left, you can see the cables running along the front of the telescope at this angle. They’re draped over the blue horseshoe structure in the foreground. Several of the cables are draped down in the lower left-hand side of the photo. There are ten cables that run from the top of the telescope to the room with the spectrographs. Each cable contains 500 individual optical fibers. Each of these cable bundles feeds one of the spectrographs at the telescope’s base. Since each cable contains 500 optical fibers, they are heavy cables. They’re also very fragile. It would be challenging enough to run these fibers from one point to another if they could be locked down in one position. However, the telescope actually has to move, so we can look at different parts of the sky. This means these heavy, fragile cable bundles have to move too.

Before construction even began on the DESI spectrograph, engineers spent time figuring out the best way to run the cables that minimized how much they had to move. Also, there are devices called e-chains that help assure cables stay nice and neat as the telescope moves. This past week, one of the engineers snapped a photo of me helping to prepare one of the e-chains for installation. He was in a lift up near the telescope’s top and looked down at me and another one of the telescope engineers hard at work. I’m the one in the yellow hard hat.

As I mentioned earlier, these cables are both heavy and fragile. That means there’s been a lot of heavy lifting that requires a great deal of care about where we step and place the cables. We don’t want to bend them too tightly, or they could break. The upshot is that this has been exhausting work. Everyone feels wiped out at the end of the day.

Still, we see the proverbial light at the end of the tunnel, or perhaps that should be the light at the end of the fiber! Once the cables are run, we only need to install the last three spectrographs, then the system will be complete. How soon we’ll start observing with the DESI spectrograph will depend on the results of preliminary testing which has already commenced and will be finished soon after the installation is complete. That said, I am told there’s a very good chance we’ll be pointing DESI at targets on the sky in less than a month. At that point, we may start to understand more about this mysterious thing that astronomers have dubbed dark energy.

DESI Naked!

This weekend finds me at Bubonicon 51 in Albuquerque, New Mexico. I’m moderating panels about space cowboys and large scale scientific surveys. If you’re in town, click the link to get the details and drop by. I’d love to see you there. Of course, part of my interest in large scale scientific surveys has to do with the work I’ve been helping with over the last year and a half, installing the DESI Spectrograph at the Mayall 4-meter telescope at Kitt Peak National Observatory. During my my recent shift at the observatory, I got a rare look at the new instrument not just “under the hood” but before the hood even went on.

In the photo above, you see DESI on the left, just over the orange platform. Standing on the ground floor in the foreground are just a few of the telescope engineers and technicians who have been installing this new, innovative instrument which will be used to make a 3D map of about a third of the known universe. DESI itself is an array of 5000 fibers mounted on robot positioners that can be precisely centered on targets each time the telescope moves. The light from those objects then travels down fibers two stories below. The fiber bundles are ready to be run along the telescope. You see them coiled up on the white carts to the lower right of the photo above. Each black cable contains 500 fibers. One of my jobs this week was labeling those cables so people can keep it straight which cable is which as they run them along the telescope.

Here are all the DESI fiber positioners mounted to the telescope. You can see each of the ten cables coming up into ten sets of fiber positioner “petals.” Each of these petals was installed into the telescope with great care about a month ago. Light was placed on all the fibers and it was confirmed that in all the transportation and installation, none of the fibers were broken. All of them transmit light as expected! This week, the control electronics are being wired up and routed through the telescope. Once this chore is complete, more testing will happen to assure that the fibers still transmit light and each of the robot positioners moves as expected using the electronics routed through the telescope.

All of those fibers will eventually come into a clean room downstairs to a series of ten spectrographs. Do you begin to sense a pattern? Ten petals, ten cables, ten spectrographs. As it turns out, another job of mine this week was helping to install the seventh spectrograph, which you see in the lower right of the photo above. Western fan that I am, I feel like you can now cue Elmer Bernstein’s score for The Magnificent Seven. Of course, that won’t last long. soon we’ll have an eighth, ninth, and tenth spectrograph.

Each of those spectrographs will be used to examine the light from 500 fibers. To make the map, we’ll be using these spectrographs to see how far characteristic chemical lines in spectra have shifted from where they normally sit within the rainbow toward the red end, which is one measure of how far away those objects are. We’ll compare that to statistics of how far apart they are, which turns out to be another measure of how far away they are. That said, just because we’re mostly looking for the redshifts, there will be all kinds of other spectral data available that can tell astronomers all kinds of information about properties of galaxies all over the sky. One of the most exciting things about the DESI program is that this data will be available to all. In this post, I may be laying DESI bare for all to see, but the whole project will be laying much of the universe bare, and in the process expanding the body of astronomical knowledge.

  • For a fictional and frightening look behind the scenes at an astronomical observatory, read The Astronomer’s Crypt.
  • To take a tour through the wonders of the solar system, read The Solar Sea.
  • To travel back in time to the Old West, check out Owl Dance!

Bubonicon 51

Bubonicon 51 will take place in Albuquerque, New Mexico this coming weekend, Friday August 23 through Sunday August 25. The guests of honor are Allen Steele, author of Arkwright, and Ursula Vernon, artist and author. The toastmaster is Darynda Jones, author of Summoned to the Thirteenth Grave. The guest artist is Greg Spalenka, who designed the logo you see in this post. The science speaker is Dr. Harrison Schmidt, the Apollo 17 astronaut, geologist, and former senator from New Mexico. The convention’s theme is “The Future is Now.” I will be there all weekend as both a guest author and a vendor. Bubonicon 51 will be held at the Albuquerque Marriott Uptown at 2101 Louisiana Boulevard. You can get more information about the convention at http://bubonicon.com.


My schedule is as follows:

Saturday, August 24

11am-noon. Main Room. Space Cowboys: Where Westerns and Space Opera Collide. Malcolm Reynolds hauled cattle on his spaceship. Captain Harlock strode through batwing doors into a few dusty saloons. Captain Kirk’s show was originally described as “Wagon Train to the Stars.” And then there’s the animated BraveStarr. At what point does the hero of a space opera become a space cowboy? How “retro” can you make your space opera before it becomes fantasy or steampunk? I’ll be moderating this panel that includes such luminaries as Robert E. Vardeman, Craig Butler, Susan Matthews, and Allen Steele.

4-5pm. Salon A-D. Surveying the Universe. Traditionally, astronomers made a hypothesis, applied for time on telescopes, took their data and examined it. That model is being replaced by large scale surveys being conducted by organizations such as the Department of Energy and NASA. What are the advantages and disadvantages of doing astronomy, and science in general, by large scale survey as opposed to small teams working on their own questions? I’ll be moderating this panel which includes John Barnes, Loretta Hall, Kathy Kitts, and Cathy Plesko.

5:25-6:40pm. Main Room. Mass Autographing. All the Bubonicon guests will be happy to sign your books, art, or whatever you happen to bring. If it has the property of mass, I’ll do my best to sign it!

Sunday, August 25

2:45-3:30pm. Salon A-D. 45 minutes with David Lee Summers. I will read from my recent work. I’m thinking a sample of the revised version of The Pirates of Sufiro, but I may include a surprise or two if there’s time.


If you’re in Albuquerque this coming weekend, I hope you’ll drop by Bubonicon and check out a few of the many panels going on over the course of the weekend. Please drop into the “flea market” where Hadrosaur Productions will be set up. You can preview our wares, or shop online, at: http://www.hadrosaur.com.

Seeing Daylight Once Again

As I write this, the DESI Commissioning Instrument run at the Mayall 4-meter telescope at Kitt Peak National Observatory will be nearing completion. The Commissioning Instrument is an array of five digital cameras that view the sky through the telescope’s new optics. Once the Commissioning Instrument comes off, the actual DESI fibers and robot positioners will be assembled at the focal plane. This is a process that’s estimated to take about three months to complete. During that time, I’ll be returning to day shifts at the Mayall telescope, helping with the installation. The DESI fiber “wedges” are starting to arrive and assembly has actually begun on some components down on the telescope’s ground floor.

There is a terrific video describing the DESI project and showing these wedges being populated with the fibers in the lab that you can watch at: https://newscenter.lbl.gov/2018/10/17/dark-energy-project-robots-3d-map-universe/

The DESI fibers are the business end of getting light from distant galaxies where it needs to go to be analyzed. Light traveling for billions of light years will be sent through those fibers to be separated and photographed by spectrographs. Before light gets to the fibers, it has to be collected by the telescope, where it will pass through an optical corrector lens. The corrector makes sure that when the telescope is focused, each fiber will also see an equally focused object. Of course, to do this, the whole instrument has to be aligned well with the primary mirror so we know each target lines up with a fiber.

The goal of the Commissioning Instrument is to give us a simple camera that lets us check that the corrector lens is doing its job. It also allows us to test the alignment and focus mechanism, which we call the hexapod. We want to make sure these critical components work before going to all the work of assembling all those fibers at the top of the telescope. In fact, during the Commissioning Instrument run, we discovered that the corrector was eight millimeters too close to the primary mirror. This was a result of telescope blueprints from 1973 not being updated with as-built specs. Eight millimeters may not sound like much, but it’s enough to keep the fibers from being in focus during the warmest nights of the year! So, the hexapod and corrector assembly were moved, which is much easier to do now than when all the fibers are in place.

I have enjoyed my day shifts at the Mayall this past year. It’s given me a chance to interact with more of the maintenance and engineering crew than I normally do in my nighttime operations. I won’t be working exclusively during the daytime. I will still spend one week a month supporting nighttime observations at the WIYN 3.5-meter telescope. If you would like a behind the scenes look at what it’s like to work at an observatory at night, along with something of a scary story, check out my novel, The Astronomer’s Crypt. You can learn more about the novel at: http://www.davidleesummers.com/Astronomers-Crypt.html