The View Up Here

Random scribblings about kites, photography, machining, and anything else

Reasons to Enjoy the Weekend

Posted by Tom Benedict on 17/11/2012

I thought I was going to spend the week finishing the cameras at work. A nice, quiet, uneventful week. Boy was I ever wrong. A series of projects and emergencies had me and my co-workers at the summit and on the go almost the entire week.

It started with an instrument exchange. These days we have three primary instruments on the telescope: Megacam, our visible light imager, WIRCAM, our infrared imager, and Espadons, our visible spectropolarimeter. Typically two of these will be used each month. When the moon is less than half full – what we call dark time – Megacam is typically on the telescope. WIRCAM and Espadons are less sensitive to moonlight, so they are our bright time instruments. One or the other will be on any time the moon is more than half full.

This was one of the exceptions. Our adaptive optics bonnette (AOB) was at the cassegrain focus of the telescope along with one of our smaller infrared imagers, KIR. AOB/KIR was slated to be removed and Megacam installed. The actual exchange went well. The rest went horribly wrong. Two of us had just finished up a bunch of work on Espadons the week before. The only step left was to put all the covers back on and check the instrument out for the sky. Once the exchange was done we popped all the covers on and ran a quick hardware check. We’ve run hundreds of these over the years without incident. This time it failed.

It turned out one of the actuators on the instrument had died. We spent the next two days coming up with a work-around while our machinist rebuilt the actuator. By the end of the second day we had our temporary fix – a micrometer head bolted to a block of aluminum – all sorted out. We also had the rebuilt actuator re-installed and checked out for the sky.

Meanwhile we were slated to pull WIRCAM out of its upper-end so that another adaptive optics system could be tested on sky. This took the better part of a day, and involved a fair bit of stress because we couldn’t let the camera warm up during the move. As soon as it was out of its upper-end, it was wheeled down to one of our labs where we hooked it back up to its cryogenic system. It never came above 85 degrees Kelvin.

While all this was going on, other members of the team were working on a possible problem with our dome shutter – the big door that has to open every night so we can observe, and that has to close every morning to keep out the sun, the rain, the wind, and the dust. Just as we finished getting WIRCAM bedded down in the lab, I was called on to help with the shutter.

So at 4pm on my third day in a row at 14,000′ of altitude, I found myself fifty feet above the ground staring across space at Megacam while my boss was squeezing himself into a crawlspace in the ceiling barely big enough to fit his body so he could take pictures of the shutter drive units. “Hey!” I thought, “I wonder if I could make a credible HDR photo using a cell phone.” So I pulled out my phone, braced it as best I could against a nearby railing, and did a five frame, five stop HDR stack.

Megacam on CFHT

It turned out pretty well, considering the contrast range, the high pressure sodium lighting, and the fact that I didn’t have a tripod, beanbag, or any other real way to steady the camera. All in all I’m impressed with the cameras that are being shoehorned into cell phones these days. It’s no replacement for a DSLR or even a good compact camera. But it’s honestly pretty darned good. I thought it particularly fitting that I was photographing what was at one time the largest digital camera in the world, using a camera so small it fits inside a cell phone.

And in case you’re wondering how I got to be fifty feet off the ground to make this picture, this is what the view was looking straight down:

Where I Was

Yup, that’s my foot. And the square yellow column just to the left of my foot is all that’s holding me up. For the part of the shutter my boss needed to access, this is the only way to get there.

And maybe this explains a couple of things:

First, I know why I like the perspective KAP offers. It’s a fascinating height to work from. I enjoy going up in the lift just to get that view. Tired as I was, I jumped when my boss said he needed someone to go up with him. It’s the closest I can come to seeing what a KAP rig would see. Things are close enough to look familiar, yet far enough away to give the viewer a fresh take on the world.

Second, it just reinforces how glad I am not to have a fear of heights. It’s amazing how much of my working life here has been spent strapped into a fall harness.

Finally, it’s just one more reason to enjoy the weekend. Even when I think I have a pleasant uneventful week ahead of me, this is typically what happens. Par for the course when working at a telescope.

So what’s in store for next week? I HAVE NO IDEA! And that’s par for the course, too.

– Tom

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