Abstract: The 'Emu' payload is a compact
wide-field photometer destined for a 6-month astronomy mission aboard
the International Space Station. Its detector technology is also
readily transferrable to Earth observation applications, including
bushfire mitigation. The Emu astronomy mission will undertake a
most-of-sky survey in the 1.4 µm water band' to reveal the oxygen
abundance properties of cool stars. It will use high-speed time-delay
integration imaging, which removes the need for active pointing
control, yet will remain sensitive enough to achieve a signal-to-noise
ratio of 10 for stars of magnitude m_AB≈12.5 (H-band). This is
achieved with a Leonardo 'SAPHIRA' linear-mode avalanche photodiode
array reading out at ~50 frames per second via ANU’s 'Rosella'
detector control electronics. We present an overview of the mission,
including the instrument design, science simulations, and our plans to
redeploy the technology in free-flying satellites for addressing
matters closer to home.