Computer tests have shown that on space telescopes where the lid is
still attached via a hinge, that certain movements of said satellite can
cause the lid to flip back and forth in microgravity. This can cause the
lid to either block partially or fully the telescope viewing area.

In some cases the lid can even reclose on the telescope opening. As
Kepler is orbiting the Sun and not Earth, a Space Shuttle repair mission
is out of the question, though NASA better think of some kind of
rescue/repair ship when it starts putting more satellites into the L1
and L2 orbits.

NASA decided not to take that risk and instead eject the lid into deep
space. The odds of this new space "junk" striking anything beyond a
few dust grains in the next thousand years are slim.

So what's in Lyra?