Defining the SIA

Monday, August 13, 2012
PN5A--side view

Operations are continuing to grapple and recover the cable segment ends for OOI RSN Primary Node 3A at Axial Seamount. In the meantime, Paul Hagstrom, OOI-RSN Associate Project Manager/Senior Project Engineer at the Consortium for Ocean Leadership, who is on board the TE SubCom Dependable for the duration of the RSN Primary Node Installation work, has provided a useful explanation of the Science Interface Assembly, which is installed in all the primary nodes except for PN5A.

Science Interface Assembly (SIA): The SIA in a primary node has all the active optics, communications, low-voltage power, and control circuitry. The SIA is designed to be installed into or removed from a primary node on the seafloor using a remotely operated vehicle (ROV). There is no science currently planned for the Mid-Plate Node, PN5A. However, in order to to complete all testing from the shore station while the node was still on the deck of the vessel, the spare SIA was installed in the PN5 frame, which is known as the Backbone Interface Assembly (BIA). Prior to launch on 11 August, the spare SIA was removed from the PN5A BIA. This SIA will eventually be stored onshore. If, at some future date, the RSN system is expanded from Primary Node 5A, the SIA will be configured and installed in the BIA to support that expansion.

--Nancy Penrose, OOI Communications Coordinator