Thursday, September 24, 2020

Good News - We're back online!

Here is a LONG overdue status update for the observatory.

You may have noticed that the RRRT has been running on Skynet. We were testing out the system before posting any official status update to ensure everything was working properly. Unfortunately time got away from us, as we intended to post an update a while ago.

We are happy to announce we are back up and running. There were a number of changes that have occurred during this extended downtime:

  1. There is a new Telescope Control System (TCS) running the telescope.
  2. We have gone back to the SBIG STX-16803 camera due to issues with the Apogee U42 camera.
  3. To cut down on scattered moon light, the inside of the primary mirror baffle tube was re-painted and a telescope shroud has been installed.
 

 New Telescope Control System

Back in October of 2019 the Telescope Control System (TCS) that had been running the telescope for approximately ten years ended up failing. This original TCS was a Software Bisque MKS4000 unit, which was unfortunately no longer in production. The newer MKS5000 model was purchased, and significant time was spent trying to get this TCS to run the telescope. Despite significant effort, and many discussions and assistance from the manufacturer, we were never able to reach a point where the controller would run the telescope. Ultimately we had to send this unit back and search for another solution.

We selected the Force One Brushless Controller from Sidereal Technology. Making the change to this TCS required re-wiring, a new power supply, and a new electronics enclosure to house everything.

Force One Brushless Controller from Sidereal Technology. Image from https://www.siderealtechnology.com/store.html









We have been extremely pleased with this new controller and the associated control software. The software, SiTech.exe, is ASCOM compliant, allowing us to control everything on the telescope from the SiTech program directly. Sidereal Technology was amazingly fast at responding to our questions, and we were able to speak directly with the owner of the company for assistance when installing the controller. Hands down one of the best customer service experiences you could ask for. In fact we were so pleased that we have decided to eventually upgrade the control systems for the other telescopes at Fan Mountain Observatory to Force One controllers.

The Force One controller has some additional features that the old TCS did not have. It has the ability to incorporate axis encoders in addition to the motor encoders we are currently using. Axis encoders were not originally part of the telescope, however we hope to add these in the future. In addition, limit switches can also be incorporated, and we hope to include these in the future as well.

 

New (old) Camera

The plan was to move forward with the Apogee U42 camera that was originally purchased for use on the telescope by Norfolk State University. However chamber issues that could not be fixed by the manufacturer caused us to abandon this plan. We currently have the SBIG STX-16803 camera installed, and plan to continue using this for the foreseeable future. The detector chip in the STX-16803 is physically larger than the detector chip in the U42 camera. Because the new tailpiece was designed for the smaller U42 camera there is now significant vignetting. We are aware of this, and we are in the process of designing a new tailpiece to correct this, however we plan to continue with the current configuration until at least the end of the semester.

We also have a new-ish filter wheel, a 10 position Finger Lake Instruments CFW3-10 Filter Wheel. The following is a list of current filters, manufactured by Astrodon:

  • Luminance
  • Sloan u', g', r', i'
  • Johnson/Cousins B, V, R
  • H-alpha
  • OIII
Telescope tailpiece










 

 Reducing Scattered Moonlight

Two modifications have been made to the telescope to reduce scattered moonlight. The first of these was to paint the inside of the primary mirror baffle tube to cover an exposed section of bare metal. For whatever reason this section was not painted originally.

The second modification was to install a shroud around the telescope tube, as seen below. These two modifications should help in reducing scattered moonlight.

Telescope with shroud

This semester we have roughly 500 UVa students using the telescope through Skynet. We hope to see some amazing images taken with the telescope, and will try to post some of those images here on this blog. For anyone who can request observations on the telescope, either through UVa or NSU time, or through Skynet, please note that your requests will take longer than usual given the volume of requests being submitted from UVa students.

If you have any comments or questions, please ask them in the comment section below. We try our best to read these and respond to them when we can.

Clear skies!

Monday, December 9, 2019

Update on the new telescope control system

Has it really been over two months since the last update? How time flies. Sorry to have kept everyone in the dark for so long (both literally and figuratively). Here is a long overdue update on the status of the RRRT and the new control system.

The replacement TCS was ordered back in October and arrive shortly thereafter. The TCS was installed on the telescope, and when powered up produced errors. We began troubleshooting, however  this took longer than we anticipated and the team had to balance this work with travel and other projects. At this point the controller is no closer to working than when we started back in October, and we seem to have run out of options. After several lengthy discussions, we have made the decision to purchase a new TCS from another manufacturer. This is largely driven by the fact that we need the telescope operational for the spring semester. We are hopeful that the new TCS can be ordered this week, and that we will have it delivered sometime over the holiday break. The goal is to have the RRRT back online by the end of January.


Monday, October 7, 2019

New Telescope Control System needed

After some extensive testing, and discussions with Software Bisque, it has been determined that the problems we were having are with the Telescope Control System (TCS). We tried new cables, USB extenders, serial ports, even changed to a different computer running TheSkyX, and the issue still persisted.

The TCS for the RRRT is currently a Software Bisque MKS 4000 model. We were repeatedly having comm timeout errors, and narrowed it down to the port on the TCS. Software Bisque says this is not an uncommon issue, especially given the age of the device.

The good news is that we have identified the issue. The bad news is that it requires replacing the TCS. To make matters slightly worse, Software Bisque no longer makes the MKS 4000, so we will need to upgrade to the newer MKS 5000.

The UVa Astronomy department has agreed to fund the replacement of the TCS. We are currently in the process of working with Software Bisque on the purchase, which will include having them configure the new MKS 5000 unit with the parameters that we extracted from the MKS 4000.

Another wrench that will be thrown into all of this is that unfortunately the MKS 5000 is not supported by TheSky6, only TheSkyX. We have been using TheSky6 to control the telescope, and will now need to switch over to TheSkyX, which the UVa Astronomy department already has a license for. We had previously tested out TheSkyX on the RRRT with Skynet and repeatedly had problems. There were some issues between Terminator (the Skynet software that runs on the computer) and TheSkyX, that did not exist between Terminator and TheSky6. What this means is that once the MKS 5000 is installed, there will still be a decent amount of on-sky testing that will need to happen. The telescope will be placed back on Skynet, but expect periodic error messages to take it offline. Depending on how things go, we may even take the telescope offline when we aren't available to watch it, for safety reasons, but that remains to be seen.

We realize this downtime has had an effect on those trying to use the RRRT as part of their classes, and will continue to be an issue at least until the new TCS is installed. Please know we are working as quickly as we can to fix these issues.

We will post updates to this blog as we move forward, so please check back for status updates. If you have questions, you can also post comments to any of these blog posts, and we will do our best to respond.

Thursday, September 26, 2019

RRRT is offline

We are having communication issues with the telescope controller. We hope to replace a USB extender tomorrow. In the meantime we will keep the telescope offline.

Tuesday, September 24, 2019

RRRT is back online

We have been running over the weekend without any issue. If you have observations you would like to submit, please start doing so. With the new setup it may take a few more clear nights to build up enough calibration frames. Please let us know if you have any issues. If you take some nice images with the RRRT and would like us to post them on this blog, we would be happy to do that.

Friday, September 20, 2019

The RRRT is back online. We are in the process of testing out the new configuration, and may experience a few hiccups, so please bear with us. If you would like to submit some test exposures, please do so. Hopefully we will have any remaining issues worked out by early next week.

Tuesday, September 17, 2019

September 2019 RRRT Update

The RRRT has been offline since early August. This blog entry is a description of what we have been doing over the past many weeks, and where we currently stand.

First, the backstory:
Back in September 2017, we noticed that NSU's Apogee Alta U-42 camera was not cooling properly. Whereas it had been getting down to -20 C on a regular basis, it was struggling to get down to -14 C. A few weeks later, we noticed spots appearing on the edge of the chip, which looked very much like ice/condensation. The camera was 9 years old at time, and clearly had a significant problem.

We removed the U-42 camera from service and replaced it with an SGIB STX-16803 camera borrowed from the UVA Astronomy Department. We sent the Apogee camera back to the factory for servicing. Apogee (now Andor) did a chamber service and returned the camera to us in the spring of 2018.

In the winter of 2017-2018, we decided to manufacture a new tailpiece to connect the camera to the telescope. At the time, we were mounting the camera and filter wheel to the 2-inch eyepiece holder (visual back). This presented some problems. First, there was no set rotation of the camera. Every time it was removed and put back on, it would have a slightly different rotation. Second, the camera and filter wheel were only held in place by set screws. We had our mechanical engineer design a very simple tube that bolts to the telescope, with a plate that bolts to the filter wheel which in turn would bolt to the Apogee Alta U-42 camera. This setup would fix the rotation of the camera, and ensure that everything was securely bolted together.

In the fall of 2018, the Astronomy Department received some funding from the Commonwealth's Equipment Trust Fund, and we purchased a 10 place Finger Lakes Instrumentation filter wheel with a full Sloan filter set, and two narrow band filters (H-alpha and O III). Thanks to a generous donation from Ben Loyola, were were also able to purchase a luminance filter. We designed the new tailpiece so that the new filter wheel could bolt on, with the camera bolted to the filter wheel.

In the spring of 2019, the new tailpiece was complete and was anodized (there was a long delay, in part because of the retirement of Charles Lam, our machinist). We decided not to change the camera in the middle of a semester because classes were using the telescope. Instead, we decided we would wait until the summer to swap back to the NSU Apogee Alta U-42, the new filter wheel and new filter set, and the new tailpiece. This would also require some rewiring at the back end of the telescope, and would offer us the chance to remove some unused wires threading through the tube and mount.

The summer was busier than expected, but by early August we were ready for the swap. In the meantime, during the summer after a thunderstorm, we noted that the Robofocus focuser was no longer working. In early August we took the telescope offline, removed the SBIG camera, filter wheel, and visual back from the telescope. We sent the Robofocus electronics box back to the manufacturer. In the end, they had to replace all the electronics in the box. Jimmy designed and fabricated two plates to mount on the back of the telescope to hold the power supplies for the camera and filter wheel and hold the USB hub. He routed a new USB cable through the mount and removed some unused serial and power cables. We reinstalled the Robofocus electronics, installed the new tailpiece, attached the filter wheel and camera. It took a few days for some clear skies before we could focus the telescope. When the clear skies arrived, we were able to focus the telescope but, unfortunately, the NSU Apogee Alta U-42 camera would not cool to even -10 C (about 35 degrees below ambient). In the past, it had cooled to -20 C (about 45 degrees below ambient). Thus, the cooling problem persists even after the chamber servicing.

In looking at the documentation provided by Andor, it appears that they could not get the camera to cool below about -10 C either. We have since contacted Andor about the camera. Since the camera was recently in for servicing, and since the camera is now over 10 years old, they believe there is nothing else that can be done. We cannot switch back to the SBIG camera as it is needed for the ASTR 5110 course this semester. We also considered switching to an Apogee U9000 that we would borrow from the Astronomy Department, but that camera would need to be returned in the spring. Rather than continue to swap cameras every semester, we have decided to put the U-42 on the telescope and see how it goes for this semester. We will set the cooling target at -5 C.

Thus, the current configuration of the telescope is:
Camera: NSU Apogee Alta U-42
Array size: 2048x2048 with 13.5 micron pixels
Pixel size on sky: 0.57 arcseconds per pixel
Field of view: 19.5x19.5 arcminutes
Filter wheel: Finger Lakes Instruments 10-position filter wheel
Filters: Luminance, Sloan u', g', r', i', Johnson/Cousins B, V, R, H-alpha, O III

We hope to get this running by early next week and will try to keep this configuration static for the 2019-2020 academic year.

The Apogee Alta U-42 is clearly at the end of its life, and we cannot rely on it much longer. The SBIG STX-16803 and Apogee U9000 cameras are general Astronomy Department cameras and cannot be mounted permanently to the telescope. Thus, in the long term, we need to find a replacement camera.