Mission OverviewESIS logo depicting a sun as half of the E

ESIS-II is a reflight of the ESIS sounding rocket. ESIS is a sounding rocket payload designed to measure the speed ofplasma in the solar atmosphere. The architecture behind ESIS is a computed tomography imaging spectrometer (CTIS) which forms overlapping images of a few solar spectral lines to measure their Doppler shift. The following image is an example image captured during the payload's initial flight in 2019.

Solar spectral line as seen during the initial flight of ESIS

Spectral line image captured during the intial flight of ESIS

Status

The initial flight of ESIS occurred on September 30, 2019. The flight was successful and captured a combination of small and large eruptions on the Sun's surface. ESIS demonstrated the advantage of CTIS over traditional slit spectrographs in capturing the spatial and spectral information of dynamic solar features aross large fields of view.

ESIS on the rail preparing for launch

ESIS on the rail during prepartions for launch on September 30, 2019

ESIS was selected for a second flight by NASA in 2023. Originally intended to be lead by a team at NASA Goddard, ESIS along with its PI Jake Parker were handed back off to SSEL in the fall of 2025. SSEL is working to ramp the project back up and make the necessary changes for the payload's eventual launch in fall 2027.

For the second launch, the plan is to remove the depracated MOSES electronics and reuse their space for expansion of ESIS-II electronics and fixtures.