Reusable Agena study. Volume 1: Executive summary

The shuttle Agena upper stage interim tug concept is based on a building block approach. These building block concepts are extensions of existing ascent Agena configurations. Several current improvements, have been used in developing the shuttle/Agena upper stage concepts. High-density acid is used as the Agena upper stage oxidizer. The baffled injector is used in the main engine. The DF-224 is a fourth generation computer currently in development and will be flight proven in the near future. The Agena upper stage building block concept uses the current Agena as a baseline, adds an 8.5-inch (21.6 cm) extension to the fuel tank for optimum mixture ratio, uses monomethyl hydrazine as fuel, exchanges a 150:1 nozzle extension for the existing 45:1, exchanges an Autonetics DF-224 for the existing Honeywell computer, and adds a star sensor for guidance update. These modifications to the current Agena provide a 5-foot (1.52m) diameter shuttle/Agena upper stage that will fly all Vandenberg Air Force Base missions in the reusable mode without resorting to a kick motor. The delta V velocity of the Agena is increased by use of a strap-on propellant tank option. This option provides a shuttle/Agena upper stage with the capability to place almost 3900 pounds (1769 kg) into geosynchronous orbit (24 hour period) without the aid of kick motors

Opéra et théâtre en dialogue. La question de l’appropriation culturelle dans la création opératique contemporaine

Based on the analysis of a challenging case from the OpéRA de poche (2021-2022) augmented-reality opera research-creation project led by the Canada Research Chair in Opera Creation, this article takes an interdisciplinary approach to the complex issue of cultural appropriation in opera creation today. The findings of studies on theatre and performance suggest avenues for reflection with potential for successful application in the opera context. The relationship between presence and representation and the intercultural relationship at the heart of the encounter fueling research-creation projects are the two axes of the dialogue that gives substance to the article, opening up a decolonial perspective. Quebec’s artistic reality, as seen in the cases of the polemic against Robert Lepage’s SLĀV and Kanata and the example of Ondinnok’s Rabinal Achí, constitutes a framework in which to consider the issues arising from new forms of technological expression in the field of opera