Multi-spectral solar telescope array.

The authors describe a new rocket spectroheliograph instrument, the Multi-Spectral Solar Telescope Array (MSSTA), that is currently being prepared for launch in August 1990. This instrument will utilize true Ritchey-Chrétien optics of 127 mm diameter and parabolic Herschelian optics of 40 mm diameter, which will allow spectroheliograms to be obtained over the soft X-ray/extreme ultraviolet/far ultraviolet spectral range (40 to 1550 Å). The performance of this new instrument should definitely demonstrate the unique combination of ultrahigh spatial resolution and spectral differentiation that multilayer optics afford for astronomical observations. The MSSTA will also represent the first astronomical use of an important new optical device, the multilayer grating. The MSSTA should obtain unprecedented information regarding the structure and dynamics of the solar atmosphere in the temperature range 10⁴ to 10⁷K.