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…

Installing TBAD
Hanging on to the side of the secondary assembly to install mounting points for TBAD

Author: Andrew

An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.

4 thoughts on “Postcard from the Summit – Installing TBAD”

    1. Your comment made me think a bit… With the ‘scopes you are used too, seeing your reflection in the primary is unusual. We park at horizon all the time, instrument changes, foul weather, secondary work, etc. seeing your reflection in the primary is quite common for us.

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