SpIRIT’s radiators after deployment, flying high over the Indian Ocean. The “Eagle”, a copper structure on the right radiator can be seen, which is designed to help dissipate heat from SpIRIT’s thermal management system. Credit: University of Melbourne
After more than 600 days in orbit, Australia’s Space Industry Responsive Intelligent Thermal nanosatellite, ‘SpIRIT’, has completed the first phase of its mission.
The satellite launched aboard a SpaceX Falcon 9 rocket in December 2023 and has circled the Earth more than 9,000 times since then.
SpIRIT’s initial commissioning phase involved testing its flight capabilities and onboard instruments, as well as deploying a selfie stick which it used to take a photo of itself and the Earth.
At launch, the cubesat weighed just 11.5kg and was condensed down to a 30cm x 20cm x 10cm cube. Now, in its final configuration with winged thermal management system and solar panels unfurled, SpIRIT measures almost 1m across.
The first image taken by the SpIRIT selfie camera, acquired over New Zealand at the end of the thermal radiator deployment sequence. The camera captures the underside of SpIRIT satellite, where mission participant logos are printed. The image includes the electric propulsion thruster payload of SpIRIT (cylindrical aperture near the bottom) and telecommunication transceivers (diamond patches and antennae). The backs of the solar panels are also visible. Credit: University of Melbourne
“SpIRIT is a complex satellite designed and built in Australia, with many components flying for the first time and hosting a scientific instrument contributed by the Italian Space Agency [ASI],” says Professor Michele Trenti, SpIRIT principal investigator and astrophysicist at the University of Melbourne.
“Now that SpIRIT has completed rigorous testing in space, we are confident it’s ready to commence the next phase of its mission, which is a truly exciting.”
SpIRIT carries Inovor Technology’s Apogee satellite bus, Neumann Space’s metal-ion thruster and the University of Melbourne’s thermal management system, Mercury communication module and Payload Management System.
It relies on a short 10-minute window within its 90-minute orbit to send data back to Earth and receive instructions via Nova System’s space ground station in South Australia.
“The SpIRIT satellite carries on board a prototype detector funded by ASI, built entirely in Italy under the guidance of [The National Institute for Astrophysics, INAF],” says Head of the Australian Space Agency, Enrico Palermo.
SpIRIT flying over Australia, looking towards the Gulf of Carpentaria and Cape York Peninsula, 42 days after deployment of the selfie camera. Despite being exposed to the harsh environment of space with extreme temperature swings that far exceeds its nominal survival range, the camera has far exceeded its expected lifetime of about one hour, and continues to operate reasonably well, albeit with some degradation of image quality. Credit: University of Melbourne
ASI’s HERMES instrument detects gamma ray bursts – the brightest and most powerful explosions in the universe. The intense flares are released by catastrophic cosmic events, such as neutron stars, the collapse of massive stars and the formation of black holes.
These events are unpredictable and can last from milliseconds to hours at a time.
SpIRIT will act as part of a constellation of low Earth orbit nanosatellites to quickly spot and alert astronomers to gamma ray burst events as they occur, so that they can be investigated further.
“The nominal operation of this miniaturised instrument, which has successfully completed the commissioning phase, has been demonstrated by pointing at the Crab gamma pulsar, detected with only 700 seconds of observation.”
SpIRIT is expected to remain in orbit for more than 1,000 days in total.