The primary function of COLLIDE and COLLIDE - 2's IBS Doors is to contain
the JSC-1 simulated lunar regolith (from
JSC) that serves as the impact media. The regolith is quite cohesive
when densely packed, however it is prone to dispersion when placed in an
active vibration environment. In the first design of the IBS
Doors, the dust may have worked past the containment devices and contaminated
the interior of the IBS's in such a way that Door functionality on some
of the IBS's was compromised. It is also possible that launch vibrations
damaged some door transport mechanisms. The new design incorporates
additional mechanical seals, a redesigned track for the door, and a shield
to protect the drive motor from the dust that escapes the IBS into the
GASCAN volume.
The new design uses an advanced self lubricating polymer as the interface
for the Door to the IBS shell. In the original design the Teflon®
guide pins became fouled by the escaping dust and induced large stiction
forces between the guide tracks and the pins. By making both sides
of the moving interface of a material with low surface kinetic friction,
designers hope to avoid this failure mode for COLLIDE - 2.
back to
COLLIDE Home Page
