Selection of Appropriate Materials at the South Pole for the 9-Meter Full Motion Antenna

The 9-meter full motion antenna developed by VertexRSI was installed at the South Pole in 2001 as part of the National Science Foundation's (NSF) Amundsen Scott Pole Station. The maximum wind specification for this antenna is 80 mph, and the worst case temperature is –110° F (–79° C) The antenna structure consists of two major components: The reflector and the pedestal. The reflector is the parabolic dish and is 9 meters in diameter. The pedestal is the structure that the reflector is mounted on. The structure also consists of a steel platform assembly and structural connections. Extreme cold temperatures required special considerations with regards to material selection. Appropriate materials that address cold temperature and brittle fracture concerns were selected carefully to account for the extreme weather conditions that the 9-meter antenna experiences at the South Pole. Structural integrity, cost, time, and workability were used to develop a final design. Stress levels in all components are kept within allowable stress limits specified by the American Institute of Steel Construction (AISC) Manual of Steel Construction, Allowable Stress Design for steel components and the Aluminum Design Manual for aluminum components. Since stress levels influence the likelihood of brittle failure, further improvements in structural integrity were implemented by increasing the margin over allowable stress requirements to 2 in steel components where possible.