SpIRIT Mission: In-Orbit Results and Technology Demonstrations

TL;DR

The SpIRIT CubeSat mission demonstrates advanced thermal management, autonomous imaging, and rapid data transmission technologies for high-energy astrophysics, providing valuable in-orbit results and operational insights for scientific CubeSat applications.

Contribution

This paper presents the first in-orbit results of the SpIRIT mission, showcasing novel thermal, communication, and autonomous imaging systems integrated into a multi-institution CubeSat.

Findings

Successful deployment and operation of the HERMES instrument for astrophysics transients

Effective thermal management using Stirling-cycle cooler and deployable radiator

Implementation of low-latency communication and AI-based autonomous imaging

Abstract

The Space Industry Responsive Intelligent Thermal (SpIRIT) 6U CubeSat is a mission led by The University of Melbourne in cooperation with the Italian Space Agency. Launched in a 510 km Polar Sun Synchronous Orbit in December 2023, SpIRIT carries multiple subsystems for scientific and technology demonstration. The main payload is the HERMES instrument for detection of high-energy astrophysics transients (Gamma Ray Bursts), and for studies of their variability at scales below 1 ms. The satellite includes a novel thermal management system for its class, based on a Stirling-cycle cooler and deployable thermal radiator, designed to cool HERMES to reduce instrumental background noise. A low-latency communication subsystem based on a sat-phone network is supporting rapid transmission of time-critical data and telecommands. SpIRIT is also equipped with a set of RGB and thermal IR cameras, connected to an on-board image processing unit with artificial intelligence capabilities for autonomous feature recognition. To effectively manage all interfaces between different subsystems and mission stakeholders, the University of Melbourne developed an instrument control unit (PMS) which operates all payloads. PMS also provides backup uninterruptible power to the HERMES instrument through a supercapacitor-based UPS for safe instrument shutdown in case of platform power interruptions. This paper first presents a mission and payload overview, and early in-orbit results, along with lessons learned throughout the mission. This work not only sheds light on the novelty of some of the on-board technologies onboard and on their potential impact to enable greater utilization of CubeSats for scientific missions, but also offers insights into the practical challenges and accomplishments related to developing and operating a multi-organization CubeSat with a complex array of instruments and systems.