1. Progress Report TDP-CART 15m Offset Antenna Collaboration National Research Council Herzberg Institute of Astrophysics Dominion Radio Astrophysical Observatory Gordon Lacy, P.Eng. May 2010

2. Initial Work Work on composite offsets was ongoing throughout 2009. With only preliminary optics, “best guess” made on mechanical configuration. Many structural arrangements have been explored. An all-molded reflector/back structure concept shows promise

3. Progress! Agreement between the TDP, NRC-HIA, and the SPDO on - the basic optics design (April 2010) Mechanical and structural design can now proceed. Absence of the final feed design can be accommodated for now - will require more input by the preliminary design stage. e.g. overall size, number of feeds, and feed weight & dimension (PAF) Structural design can now be progressed An optimal design will take 3 to 4 months - It cannot be done more quickly with the current resources.

4. Plan to Move Forward Close collaboration between NRC-HIA and the TDP has just begun. - Much preliminary work has been completed Building on this work, the near-term goals are to design: a.Composite primary and secondary reflectors b.A tubular backup structure, either in all metal, or in a combination of metal and composite c.Feed and secondary support system again in all metal or in a combination of metal and composite d.Compare performance versus cost for the various design options e.Compare with our previous offset designs to gain more information on cost versus performance f.Prepare for a CoDR some time in late 2010

5. Collaborative Work Current division of labour with TDP NRC-HIA providing: all composite design and analysis all dish and backing structure FEA analysis including FEA on metal parts wind-loading data from wind tunnel work on offset dishes TDP providing design and analysis of: drive systems mount and tower metal backup structure parts Combined developments: backup structure feed-leg structure feed indexer

6. Current Design Work has just begun on the 15m offset Gregorian dish for DVA-1 The design includes elements from NRC and ATA designs. Elements of interest in current design: One piece molded FRP primary and secondary dish surfaces. Steel or Steel and FRP tube backup structure. Feed legs based on topological optimization studies Secondary mount provides shield for feeds

7. Questions?