Just doing some quick back-of-the-napkin math, 1,600 miniature bayonet sockets potentially add up to hundreds of pounds of mass. That may have been a factor in

Just doing some quick back-of-the-napkin math, 1,600 miniature bayonet sockets potentially add up to hundreds of pounds of mass. That may have been a factor in the decision to solder the bulbs directly onto the boards. Especially when replacement probably required disassembling panels, so the soldering isn't really time worth saving. Just a guess though, and the significance varies quite a bit depending on where you set the slider for "mass of one socket." Still, it's the same order of magnitude that they shaved off when they decided not to paint the external tank, so it's plausible.