Published online by Cambridge University Press: 14 August 2015
A description is given of a rocket payload designed to record high resolution ultraviolet stellar spectra using the star-stabilised ‘Skylark’ rocket vehicle. The system consists of a 35 cm aperture f/12 Cassegrain telescope and a spectrometer in which the high spectral dispersion of an echelle grating is crossed with that of a plane grating to separate the echelle orders. The spectrum is focussed onto an electrostatic image intensifier tube, the fibre optic faceplate of which is coated with sodium salicylate to give ultraviolet sensitivity. Photographic film is used to record the two dimensional spectrum array with a resolving power λ/dλ ≃ 104 between 1200 Å and 3000 Å. Efficiency measurements of components indicate that the photometric efficiency of the entire system will allow spectra to be recorded for early-type stars which are brighter than mr ≃ 5.