Total and Spectral Solar Irradiance Sensor 1

Enhancing the legacy of solar radiation measurements

The Total and Spectral Solar Irradiance Sensor (TSIS-1), is a heliophysics mission consisting of two instruments (the Total Irradiance Monitor (TIM) and the Spectral Irradiance Monitor (SIM), currently operating on the International Space Station. The overall goal of TSIS is the accurate measurement of total and spectral solar irradiance for better understanding of solar forcing variations and their impacts on the Earth climate system. The TSIS observations are the follow on to 17 years of observations from the Solar Radiation and Climate Experiment (SORCE) mission and 4 years from the Total Solar Irradiance Calibration Transfer Experiment (TCTE) mission. TSIS-1 continues the important data record of total and spectral irradiance from 2003 through present day, albeit with higher accuracy, increased precision, and improved stability.

Mission Class:


Mission Status:


LASP Roles:

Research, Instruments, Data, Mission Operations, Engineering, Lead Institute

Science Target:


Mission Focus:

Solar Irradiance

LASP Mission Site:

Launch Date: Delivery to ISS on December 15, 2017; Instruments powered on in March 2018
Prime Mission: 5 years

Lead Institution: LASP

Lead Funding Agency: NASA

Partners: NASA’s Goddard Space Flight Center, SpaceX