TSS fixing: the full story

The clouds went in and out with the TSS problems. AO team discovered a problem with the Thin shell Safety System (TSS) that helps the mirror against the wind effects.  One crate was not applying any TSS current.

Both Microgate and Arcetri teams at this point turn the system upside down and started bravely to act on the rear of the crates…


The currents setting of the TSS where slightly decreased in order to avoid a DC DC converter to go crazy. After that a cleaning is a must.

The system were restored in the working position.

… and finally verified all good….

At this point we can say good by at our Microgate friends that are going home.

Good bye, see you!

Guanaco Sad

Unpacking Day 11: The Clouds Break

The storm is finally gone, and the beautiful clear sky is back. The TSS is fixed too, and after we installed our gimbal mirror motors the W-unit is complete.

It's nice to see the sun again, and to not feel like you're going to blow away.
The white light calibration source, in focus in the SDSS i' filter. Note the 3.2 pixel FWHM.

This (kind of lame) video shows our little W-Unit robot responding to a Board Setup command. This tells it to go to a set of pre-determined positions which makes it ready to operate.

The Burros came back after the storm. We hadn't seen them for a few days. A Guanaco walked by at lunch, so they're around somewhere.
Saturday was GTL night.

At this point most of our urgent critical path stuff is done, and we are starting to relax a little. We have a few more days of ASM testing to do, and some mundane odds and ends in the W-unit to take care of, like cable management. We also plan to do some testing of our software interfaces with the telescope control system.

Horses at LCO

Look what the wind blew in. We met some new LCO denizens this morning. When Laird left his room for breakfast he was surprised to find a horse standing just outside his door.

Outside the dorm this morning, this horse was waiting for Laird to wakeup.
Not camera shy.
Am I in your way?
The herd grazing below the telescopes.
Later, they moved down into the valley east of the road.

By the way this post is especially for horse lovers Emmeline and Annabel Close, who I hear are following along at home and requested some more animals.

Hi Ladies. This was at our favorite Florence pizzeria last summer.

Unpacking Day 10: Aligned W

The PI got hit with a rock this morning. That’s how hard the wind was blowing. He’s o.k., and the wind has died down tonight.

I’ll let Marco update us on progress with fixing the TSS. For now here are a couple of pictures of the work being done there:

The ASM was flipped all the way upside down to work on the TSS.
The fix required going deep into the electronics of the unit.

Laird and I finalized the alignment of the W unit tonight. It looks like none of the components shifted during shipping so we don’t have to re-align anything on the board – a big relief. We also took a set of readout noise measurements, with decent results. Things are as good or better than they were at Arcetri. For the AO-nerds out there, the CCD 39 (our WFS camera) is turning in around 9 electrons RON at 1 kHz frame rate, and roughly 4.2 to 4.4 electrons on our slow (~100 fps) mode. We had both cameras running and were modulating during these measurements, so we fell pretty good about them.

A few pictures of the WFS in the NAS:

The W-Unit, our WFS, mounted in the NAS. When it's mounted on the telescope you would have to be standing on the primary mirror to get this view.
This is the VisAO side of the W.
Here we're checking the aligment of VisAO's new gimbal mirror. We're going to attach the motors to it tomorrow.
We left the lab about 10 minutes too late to catch what must have been a gorgeous sunset. Crappy observing weather.

Some good quotes from the last 2 days:

“It’s pretty hard to keep VisAO down for more than an afternoon.” (Jared Males, spectacularly wrong)

“No! I want this to be a bonding ritual between us – and you know we’re going to do this every time we come up here.” (Laird Close, after Jared whinged about taking the same measurement for the 427th time in the last year).

“My attiude is when something is unknown, take the conservative choice, so fix it.” (Armando Riccardi, the ASM man)

For my mom again. This seemed like an awesome idea . . . I didn't notice the bird poop until later. Baade is behind me, Clay further back.

Unpacking day 9 (bis): Not all the donuts are with a hole…

Man, the ASM seemed to work really well and the AO group continue testing the system all the day BUT at a certain point the system started whistling!!! All the actuators were disabled, the system powered off and the shell was safe against the reference body but it was still whistling at about 2 Khz!!!!

Microgate people found the problem on the TSS (Thin shell Safety System): a single crate, after a while, was not applying constantly the wind safety current and caused the shell oscillation

That crate was oscillating with few [nm] RMS movements:

On the Unpacking day 10 Microgate people will address the problem.

Sadly, Microgate people were forced to delay their flights…

…but we are happy to work again with them!