A Path to the Stars: The Evolution of the Species

Table 2

A comparison between the two available foci, Nasmyth and Cassegrain.

Nasmyth		Cassegrain
M3 between M1 and M2		No M3 and mountings between M1 and M2
Higher moments of inertia		M1 & Instrs’ reduced moments of inertia
Only two (probably one) derotation		Required a further derotation
Mass (El stru. + Instr.): 69823 Kg		Mass (El stru. + Instr.) M: 60127 Kg
Elevation 0^∘	Izz: 174000 Kgm^2 (Az)	Elevation 0^∘	Izz: 128000 Kgm^2 (Az)
	Ixx: 229000 Kgm^2 (Alt)		Ixx: 161000  Kgm^2 (Alt)
Elevation 90^∘	Izz: 258000  Kgm^2 (Az)	Elevation 90^∘	Izz: 160000  Kgm^2 (Az)
	Ixx: 229000  Kgm^2 (Alt)		Ixx: 161000  Kgm^2 (Alt)
Unbalance Factor (Az 0^∘/90^∘): 1,48		Unbalance Factor Izz (0^∘/90^∘): 1,25