CMS Solution for Lockheed Martin – Orion Heat Shield

Lockheed Space Systems – Denver, Colorado facilities include their CDS, or Composite Development Shop where composite structures for a variety of space applications are designed, machined and assembled. Between 2012 and 1013, Lockheed contracted CMS Industries /CMS North America to design and build two Poseidon machines that were subsequently supplied and installed.

The larger of the two machines is a CMS Poseidon 38/75 model, which is about 7.5 meters in length by 3.8 meters in width and includes some unique features, including:

1. A moving table system that allows for either a part to be loaded onto the moving table outside of the machining area, and then positioned into the machining area via rails, or a work fixture/work-piece setup that can be positioned into the machining area without using the table. The table is approximately 20’ wide by 20’ deep. When rolled into the machining area (on special rails), the table is positioned directly over six CMS supplied pneumatic lifts that when engaged into the table mounts, slightly lift and position the table so the overall surface flatness and position relative to the machine travels is within .020”.

2. The machine was specially designed to fit into a space constrained room that included concrete walls on each side of the machine. The machine design incorporating modified vertical supporting structures that would still provide the necessary work area travels was created.

3. A modified version of the front door/frame unit that allows for the crane cables to pass through.

The original intended (and still current) use for this machine was for spacecraft hardware. However, after the machine was ordered, Lockheed corporate re-directed the new Orion spacecraft heat shield work to the CDS – Littleton Colorado facility as the newly ordered CMS machine was the only machine large enough to handle the work piece size within Lockheed Space Systems available machine inventory at that time.

The main machining operations were:

1. Surfacing the inside of the composite shell. Approximately 15 – 20% of the inside of composite shell required machining. These surfaces were machined to match the curvature of a mating titanium surface.

2. Drilling operation on the titanium surface. Positioning of the titanium material/work fixture assembly into the machine, utilizing the six pneumatic lifts to accurately position the assembly. Then a drilling and reaming operation began resulting in over 2,800 holes titanium/composite drill stack with the use of a speed reducer mounted to the end of the CMS spindle.

3. Match drill and ream heat shield assembly. The titanium structure and composite shield were then loosely mated, and re-positioned into the machine for a critical match drill and reaming operation to the same + 2,800 hole locations that were previously drilled.

4. Countersinking outer shell hole locations. Finally, a critical countersinking operation was needed for all +2,800 hole locations to ensure a flush mount fit of the fastener to the outer composite shield surface. A specially developed Lockheed Martin “PINC” countersinking head and tool mechanism that mounts directly to the HSK spindle interface was utilized to complete the countersinking operation.