Requirements(s):

There shall be a front plate that spins independently of the launcher.

Design Intent:

This front assembly will make contact with the RSO, protecting the SV. The assembly will also protect internal mechanisms for launch and RPO. The assembly will open for net release.

Implementation:

Four door plates were mounted on spring hinges and secured for launch with a Nichrome burn wire. The spring hinges were attached to a rotating assembly.

The rotating assembly also translates, which will be covered below. The rotating assembly was locked down for launch (rotation and translation) with a hook and solenoid.

Requirement(s): 

There shall be a braking mechanism capable of generating variable friction between the front plate and the structure.

Design Intent:

The first thought is brake calipers or magnetic damping, but those add cost. A simple clutch that applies more braking force the harder it's pushed against should be used. Since we're already using a winch to pull the RSO in, we can control how the clutch is being depressed by adjusting the tension in the winch line, avoiding an additional actuator.

Implementation: 

Linear guide rods and bearings allowed a friction plate to translate up and down without binding. The friction plate had springs pushing it up towards the doors.

The rotating assembly rested directly on top of the friction plate.  The friction plate had a Delrin surface glued to it to control friction between the two assemblies. Increasing the Delrin ring OD increased the friction surface area.

Requirement(s):

The front plate shall be constrained with low friction.

Design Intent: 

For damping to be variable, with no winch tension pulling on the clutch, rotational friction needs to be negligible.

Implementation: 

Delrin rollers were incorporated, allowing the rotation assembly to glide smoothly in the radial direction.