The principal change in the instrument since launch has been in the UV spectrometer. The throughput of the spectrometer suffered from significant initial degradation early on in the mission and later stabilized and experienced a much slower decline. There was a larger-than-needed signal at launch and so this degradation has only impacted the data slightly over time. The figure below shows that change in the UV and visible spectrometer since launch. This degradation has slowed down significantly in the last few years of the mission, and since late 2023 there has been a small recovery in the signal from the UV channel as can be seen in the bottom left panel of the figure below.