Postcard from the Summit – Three Strikes
Category: Postcard from the Summit
Photos from the top
Working Together One Last Time
You could always tell when the interferometer was on-sky. Both telescopes would be pointed at the same object, both domes open to the same direction. Any other time you will find each Keck telescope doing its own thing. With the interferometer shut down, it will be an odd night indeed when the telescopes are pointed in the same direction.
Postcard from the Summit – Tertiary Tower
Postcard from the Summit – Snowing
Postcard from the Summit – Weather Tower
Postcard from the Summit – Mirror in the Hall
The radio call goes out… “Mirror in the hall, mirror in the hall!” Everyone gets out of the way as a mirror segment is rolled down the central hallway. It is being moved to the coating facility where it will be cleaned, stripped and re-coated with a layer of fresh aluminum.
Postcard from the Summit – Sunrise
Postcard from the Summit – First Target of the Night
Postcard from the Summit – Installing TBAD
Hanging 60ft over the concrete below… fun!
I spent the day drilling and tapping holes into the side of the Keck 2 secondary assembly at the front of the telescope. This is to install two pieces of steel that will serve as a mount for an electronic module behind the secondary mirror. The only way to do this is to climb out onto the secondary assembly. Not a job for anyone that has a problem with heights.
Mind you I am tied to the telescope with safety straps and a full harness. While a fall would not be fatal, it would be an experience in hurt, slammed up against the steel when the straps catch the fall.
The system I am installing is TBAD. I will have to write more about it later, a quick description for now. TBAD is a method of detecting aircraft in front of the telescope, intended to shutter the AO laser before we illuminate an aircraft. It will use a directional antenna to receive transponder transmissions from the aircraft. Of course, the antenna needs to be mounted to the telescope along with the receiver electronics. Thus today’s work.
When you read this I will probably be back at it. Today I will be pulling the cable for the system to the secondary. This is done using our JLG man-lift, a hydraulically powered basket/crane that can access much of the telescope. I think I remember how to drive it…
Postcard from the Summit – Daytime Shutters
Normally we do not open the shutters during the day. As any kid who has used a magnifying glass in the sun knows, direct sunlight and optics are a powerful combination. The amount of sunlight a 10 meter mirror could gather would result in something a bit more powerful than a child’s toy.
Occasionally it is necessary to do maintenance on the shutters, in the process opening the shutters during the day. It is a careful operation, turning the dome away from the Sun and positioning the telescope away from the opening. Still, it is an odd situation, daylight streaming into the dome, a place normally only lit by starlight or the dome florescents. Then there is the view…
