If you use a shallow wedge prism or very low dispersion diffraction grating (e.g. circa 100 lines/mm) front of a camera, you can photograph the spectra of stars with a modern DSLR camera with a fast, wide field lens fairly easily I believe.
If one prepared for a bright satellite pass and oriented the dispersion perpendicular to the expected path, one could capture the evolving spectrum of the satellite as it tumbled or passed in or out of Earth's shadow. You'd have to do a little processing/averaging of the image to get a spectrum.
Has anyone seen an image like this published somewhere, or has made one of them oneself?
One example of the kind of hardware I'm talking about his this, but it would be better to use something with very low dispersion but without blocking the full aperture of the lens.
I don't mean to advocate a commercial product, this is a handy example, and Tom Field is a contributing editor to Sky and Telescope magazine.
above: from here.
above: from here