Today the scalpel finally went in! Or perhaps it was Saint George plunging his sword into the dragon? Either way - it was a big day... the first major mechanical intervention & with that, the end of optical innocence!
Having made all the measurements & carried out all the tests we could stand, it was time have a go at removing M4. This will be necessary for the M5 test that will allow us to evaluate the surface figure of M5 (coming soon to a Karoo clean room).
The mounting blocks for the 3 vanes of the M4 spider each have bolts for tangential & radial adjustment, as well as non-adjusting Z-bolts that secure the desired vertical location. These all had to be undone & removed before the mirror could be extracted.
First the tangential bolts were undone...
Then the radial ones...
& finally the Z-bolts.
With all the bolts removed, M4 & its vane assembly could be lifted out of the SAC & relocated to its cozy new box where it spent the night.
Behold - our new 3 mirror corrector!