Spaceborne applications present a challenging environment, subject to radiation, where camera lens servicing or replacement is highly undesirable. With the exception of fused silica or quartz all standard ‘lower cost’ UV-visible glasses react to gamma, neutron and x-ray radiation by turning dark. This means that if you are using a standard lens in areas where there is background radiation in weeks or a few months you will lose your image.
A study from Resolve Optics provides an introduction to specialist radiation tolerant optical glasses incorporating Cerium Oxide. A radiation tolerant lens will continue to work until it has exceeded its accumulative dose of radiation. In the case of Resolve Optics non-browning lenses they are rated for 100,000,000 rads. Therefore, depending on the level of radiation they are exposed on a daily basis the lens have an operational life of around 10 years.