The SpIRIT mission: An Australian Space Telescope contributing to multi-messenger astrophysics.

Orbiting telescopes have traditionally required at least a medium sized satellite platform to provide the necessary on-board power and volume to host remote sensing instrumentation, as well as associated support systems and general avionics. The Australian-Italian SpIRIT CubeSat mission - launched in a low Earth orbit in December 2023 - is demonstrating the potential for breakthrough science and technology through a 12kg satellite equipped with innovative payloads. SpIRIT's main instrument is the HERMES telescope - covering the 3keV-2MeV energy range for identification of high-energy astrophysics transients and for studies of their variability at millisecond scales. The satellite also includes a novel thermal management system for its class, based on a Stirling-cycle cooler and deployable thermal radiators, designed to reduce instrumental background noise on HERMES, and aimed at demonstrating feasibility of cooling IR focal plane arrays on future CubeSats. I will present a brief mission overview and the in-orbit results from HERMES observations. Finally, I will conclude with lessons learned throughout the mission development and operations, highlighting opportunities for distributed aperture constellations of nanosatellites to play a pivotal role in multi-messenger astrophysics during the next decade.