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.

Monday, September 2, 2019

Hello World!

This is the first blog post of the Rapid Response Robotic Telescope at Fan Mountain Observatory.