At first we should take a look at how the spectrograph will help us. The scattering of the sunlight in the metal dust cloud will depend on the particle size. We have the geometry and the particle size, and we could with that information make a model of the expected spectrum. The task is then to compare the retrieved spectrum with the expected one.
One issue while designing the spectrograph will be the limited space inside the Free Flying Units lower part, after it got stuffed with all the bulky injection equipment. Below is an example of how a possible set-up of the spectrograph could look like. Another issue will be to decide which wavelength range the spectrograph must have. We already have a sensor (below) with a resolution of 2592×1944 pixels, so with a greater range, comes a poorer resolution.
When we have a prototype we will start doing tests together with the injection tests in the nice looking vacuum chamber. With a light source through the top window and the spectrograph recording from another, we will get a first picture of how the spectrum could look like. Stay tuned, and you will most certainly see how that will look like later on.
/The SCRAP team