Mirror Assembly Bonded Joints for the POEMMA Balloon with Radio (PBR) NASA Mission

POSTER

Abstract

The POEMMA Balloon with Radio (PBR) mission aims to measure ultra-high-energy cosmic rays (UHECRs), neutrinos, and high-altitude, horizontal air showers. The onboard 16-segment concave mirror assembly is joined to the telescope frame using epoxy-bonded Kovar pads. We evaluate the thermal and structural resilience of the epoxy bond to the Kovar flight pads through tensile and shear configuration tests under both shock loads and long-term loads, while replicating the thermal conditions experienced in past POEMMA missions. We find the pad/mirror bonded joint withstands forces of 8G in all test configurations, with greater than a 200% safety factor, greatly exceeding NASA flight requirements for bonded joints. We demonstrate the procedure for the assembly of the individual mirror segments, both the bonding procedure of the flexure assembly to the glass and the integration of the mirror segments into the full mirror assembly.

*The authors would like to acknowledge the support by NASA award 80NSSC22K1488 and 80NSSC24K1780, by the French space agency CNES and the Italian Space agency ASI. The work is supported by OP JAC financed by ESIF and the MEYS CZ.02.01.01/00/22_008/0004596. We gratefully acknowledge the collaboration and expert advice provided by the PUEO collaboration. We also acknowledge the invaluable contributions of the administrative and technical staffs at our home institutions.

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February 1989. Prepared for the 44th Annual Conference of SPI Composites Institute, Dallas,
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[2] Columbia Scientific Balloon Facility. Structural Requirements and Recommendations for Bal-
loon Gondola Design (820-PG-8700.0.1A). CSBF Directives Technical Report 820-PG-8700.0.1A,
NASA Columbia Scientific Balloon Facility, Palestine, TX, November 2024. Effective date: Novem-
ber 5, 2024. Expires November 5, 2029.
[3] Viktoria Kungel. Optics and pre-flight testing of the telescopes of the Extreme Universe Space
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Presenters

  • Luke Wanner

    • Colorado School of Mines

Authors

  • Luke Wanner

    • Colorado School of Mines

  • Conrad Shay

    • Colorado School of Mines

  • Eric Mayotte

    • Colorado School of Mines