The Extreme Ultraviolet Spectrometer (ESP) instrument, part of the Solar Dynamic Observatory (SDO) EUV Experiment (EVE) instrument suite is a direct descendent of the Solar Orbiting Heliospheric Observatory/Solar Extreme Ultraviolet Monitor (SOHO/SEM) instrument now orbiting the Sun one million miles from Earth using the same Extreme Ultraviolet (EUV) transmission grating technology developed at MIT.

The NASA SDO, with its launch planned for 2008, is the first mission for the NASA Living with a Star (LWS) program. The SDO mission will provide measurements and models of the solar radiation and dynamics that can disturb Earth's space weather environment.

The ESP will provide a stable reference for EVE/Multiple Euv Grating Spectrograph (MEGS) Spectrometers with 5 wavelength bands covering 0.1nm-64nm and will provide a fast, stable and accurate data product for Space Weather.(0.25 s integration time with a simple calibration). the instrument technology is based on well proven and highly reliable optical elements including high ruling density tranmission gratings that are not susceptible to reflection degradation and the use of stable photodiode detectors. The ESP represents an evolution of the SEM with additional capabilites such as the ability to observe more spectral lines, and the use of a quadrant detector in the central-order to provide in-flight pointing information.