Payload Design

AU03 INSPIRE-2 will carry five unique payloads:

  • Nanophotonic Spectrograph (Chris Betters, Sergio Leon-Saval, and Joss Bland-Hawthorn, U. Sydney)
  • Radiation Counter (Joe Khachan, U. Sydney)
  • Microdosimeter (Xiaofeng Wu, U. Sydney)
  • Kea GPS Receiver Unit (Andrew Dempster, UNSW)
  • multi-needle Langmuir Probe (MNLP) supplied by the QB50 Project

Nanophotonic Spectrograph


Nanospec is a novel nanophotonic spectrograph in the visible range that has been developed by the Space Photonics Group (also members of the Sydney Astrophotonic Instrumentation Labs (SAIL) and the Institute of Photonics and Optical Science – IPOS), School of Physics, University of Sydney. It has no moving parts and consists of 7 optical fibres connected to a photonic grating, plus a small lensing system that images the dispersed spectra for the fibres onto a standard detector board for a mobile phone camera. The fibres point in 3 directions through the CubeSat walls. The fibres are protected in tracks on a 3D-printed PCB on which Nanospec is also mounted. Nanospec uses 3.3 V power and transmits its data via UART to an Auxiliary Board, from which the data is sent to the OBC.

Radiation Counter

radiation counter

The Radiation Counter is a standard Geiger tube system that is very low mass and relatively small. Developed by the Fusion Plasma Physics Group, School of Physics, University of Sydney, the Radiation Counter uses 5 V power, a low power transformer, and a Geiger tube to count high energy photons (X-rays and gamma rays), most of them resulting from high energy electrons and protons impacting the metal spacecraft body. Pulses from the Radiation Counter are sent (on a wire) to a Counting Register on a processor on the Auxiliary Board, which then sends counts to the OBC. The Radiation Counter obtains its power from the Auxiliary Board but is mounted on a separate payload board (the Radiation Board).



The Microdosimeter is a standard solid-state scintillator system that uses 3.3 V power and is very low mass, volume, and power. It was developed in the Space Engineering Group, School of Aerospace, Mechanical, and Mechatronic Engineering (AMME), University of Sydney. Its pulses are sent (on a wire) to a Counting Register on a processor on the Auxiliary Board, which then sends counts to the OBC. The Microdosimeter obtains its power from the Auxiliary Board and is mounted on the Radiation Board. The 2 Counting Registers on the Auxiliary Board provide counting services and power to both the Microdosimeter and Radiation Counter.

Kea GPS Receiver

kea gps receiver

The Kea GPS receiver is a payload developed by UNSW Australian Centre for Space Engineering Research (ACSER). It is a multi-experiment GPS hardware board testing in-orbit positioning, GPS Radio occultation and GPS Reflectometry technologies. It is one of the first technology demonstrations for a single-board GPS receiver that can host multiple experiments. The Kea is mounted and secured onto a daughterboard and installed into the INSPIRE 2 as a standard payload.

Multi-needle Langmuir Probe

multi needle langmuir probe

The multi-Needle Langmuir Probe instrument works by measuring the current collected individually from four needle probes, placed in front of the satellite's shock front. The collected current is converted to voltage, filtered, digitalized and then sent to the central telemetry (TM) system. By using data from four fixed-bias Langmuir needle probes, sampled at the same time, the plasma electron density can be derived with high time resolution without the need to know the electron temperature and the spacecraft potential. With the selected needle probe design and the estimated electron densities, the instrument is capable of measuring currents ranging from 1 nA to 2 µA. The m-NLP system consists of one data acquisition PCB, one PCB which acts as the mounting plate for the miniaturized Langmuir Probes, one aluminium top plate and an integrated electron emitter on top.