TMT at sunset. View of the telescope structure and mirrors through the enclosure opening. The inside of the dome is illuminated to show one of the two Nasmyth platforms to the left, and the telescope in an inclined position with its primary, secondary and tertiary mirrors. The secondary mirror is seen in reflection on the primary mirror.
The TIO Secondary Mirror Support System and Positioner Assembly (M2SSP) team is thrilled to announce the successful completion of our Preliminary Design Review (PDR). The PDR was held at the offices of our M2SSP supplier AMOS in Liege, Belgium from July 15–17, 2024. This critical milestone was achieved with the active participation of both in-person and remote attendees.
The AMOS team was represented by Olivier Pirnay (M2SSP project manager), Gregory Lousberg (systems engineering manager), Eric Gabriel (mechatronic engineering manager), Jean-Marc Schumacher (FEM engineer), and Laurent Wéra (electromechanical engineer).
TIO representation at AMOS included Art Mihill (M2SSP work package manager), Ben Gallagher (telescope optics group leader), Dr. Gelys Trancho (Review Chair, project systems engineer), Mike Sheehan (reviewer, enclosure group leader), Jimmy Johnson (reviewer, telescope controls group leader), Tomas Chylek (reviewer, sr. opto-mechanical engineer), and Eric Hansen (observer, deputy project manager and telescope department head). An external reviewer, Bill McBride from NOIRLab, also traveled to Belgium for this review. Larry Stepp, who previously led the TIO Telescope department, was an active reviewer through remote attendance. Other members from TIO Systems Engineering, Observatory Software, Telescope Structure, and QA/Safety teams participated remotely in design team and observer roles.
M2SSP PDR participants at AMOS in Belgium and remote
The meeting featured comprehensive presentations and discussions that covered the M2SSP preliminary design and outlined the actions required in the imminent final design and future phases. After introductions, TIO gave an overview of the M2SSP design and development, presented by Art Mihill, along with systems engineering processes and M2SSP documentation status, presented by Jamie Dodge.
The key remainder of the presentations were led by AMOS, addressing all review scope topics: hazard analysis and risk assessment, risk register, M2SSP product breakdown, opto-mechanical design, software and controls, bonded interface with the secondary mirror, mechanical interfaces and handling plans, compliance and verification, and continued development plans, including supplier fabrication and integration and site assembly.
The collaborative effort between AMOS and TIO set a robust foundation for the final design phase which will commence on August 15, 2024.
The review panel was highly impressed with the design and materials presented, recognizing the thoroughness and quality at the PDR level. Their feedback and recommendations align closely with AMOS and TIO's expectations for the final design phase with key recommended actions already considered as part of the M2SSP final design plans.
The reviewers’ expertise was invaluable in providing both reassurance of the team’s path forward and insightful comments to further enhance the project.
TMT M2SSP preliminary design. The secondary mirror (M2M) will be mounted in a steel mirror cell (M2CA) that contains the axial and lateral supports for the mirror. An internal interface (AMOS scope) exists between the M2CA and the hexapod M2 positioner (M2POS). The M2POS interfaces with the Telescope Structure. Image credit: AMOS
Some highlights from the review panel’s outbriefing include:
● The review committee commended TIO and AMOS for an effective PDR noting the high quality, clarity, and comprehensiveness of the documentation provided well in advance.
● The review process, utilizing the review item (RIX) spreadsheet, effectively focused attention on various design and systems engineering aspects.
● TIO Optics, Systems Engineering, AMOS, and the M2 Positioner sub-contractor were complimented for achieving a relatively mature preliminary design within just nine months post-kickoff.
● The design, based on successful similar designs by AMOS, significantly reduces risk.
● The PDR was deemed successful with a recommendation to proceed to the final design phase.
Key recommendations for the final design phase include updating interface documents, addressing requirement changes early, optimizing design for driving requirements, developing a comprehensive hazard analysis, and enhancing planning and coordination for testing and assembly.
The PDR marks a significant progression in the M2SSP development, reinforcing our commitment to developing this critical subsystem of the TMT Observatory. Funding for this work was awarded to TIO through the National Science Foundation design and development funding. Both AMOS and TIO are excited to move forward into the final design phase guided by the valuable feedback from our reviewers.
We extend our gratitude to all participants and look forward to continued success as we advance towards the next phase of the M2SSP development.
This material is based upon work supported by the National Science Foundation under Cooperative Agreement No. 2331108. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
TIO remembers Ed Stone
TMT Primary Mirror Segment Control System PDR Successfully Completed
