Orbita for Stray Light characterisation on IACSAT-1 mission

Stray light is simply unwanted light that reaches a telescope and contaminates the measurement. For space-based observatories, it can reduce contrast, bias faint-signal detection, and ultimately limit mission performance.

Before considering how the instrument manages it internally, we must first understand what arrives at the instrument entrance. In orbit, major contributors are bright extended sources such as the Earth and the Moon. Their radiance is not constant; it varies with phase angle (how illuminated they appear), surface reflectivity, viewing geometry, and orbital conditions. Quantifying this external illumination is the foundation of any robust stray-light strategy.

Hisperion is collaborating with the Institute of Astrophysics of the Canary Islands (IAC) within the framework of the IACSAT-1 mission. This mission is dedicated to the astronomical observation of space, with a main instrument designed to detect and characterise exoplanets. The IAC will use Orbita to characterise stray light at the entrance of the instrument at any epoch. Orbita will provide the IAC with the ability to perform GPU-accelerated stray light calculations at any epoch, relying on high-precision ephemerides and dynamic models.

This work is being carried out under a contract within the framework of the IACSAT-1 project, funded by the European Union - NextGenerationEU, under Spain’s Recovery and Resilience Plan.