The Total and Spectral Solar Irradiance Sensor, or TSIS-1, has finally been powered-on. It was launched in December of 2017, aboard a SpaceX Falcon 9 and installed in the International Space Station two weeks later. The first sensor began collecting data in what is commonly known as its “first light” phase in early January. The second saw first light in early March.

The instrument is meant to provide NASA with long-term data about the emerging flowing from the sun. Scientists hope the information can help them understand what kind of influence the sun has on various aspects of Earth, including its radiation budget, the ozone layer, and its ecosystems. Ultimately, they hope to fully comprehend the effect the sun has on climate change.

This instrument was put through extensive testing prior to the launch. The pointing platform was tested for over two months at the University of Colorado. Each one of the solar instruments was then extensively tested. Since TSIS-1 uses a monitor to study the energy emitted by the sun, it was crucial that developers ensured each one of the sensors worked. One of them is meant to study the sun’s energy on Earth over a 40-year timeframe. The second is called the Spectral Irradiance Monitor, and it studies how the light and radiation emitted from the sun is spread out over the spectrum of light, including ultraviolet, visible, and infrared regions.

Diverse measurements like these are crucial for research because each type of light effects and interacts with Earth differently. For example, ultraviolet light readings help scientists understand the interplay between the sun’s radiation and the Earth’s ozone layer. Through studying the impact the sun has on the Earth through this type of spectral analysis, scientists hope to find a way to prevent drastic climate change events from happening. At the very least, they are hopeful to find ways to anticipate certain changes and mitigate their effects. The TSIS-1 is expected to gather a 15-year record of this information.

Since its launch and installation aboard the International Space Station, the entire system is working exactly as expected. The hard work now lies in interpreting and validating the data it provides. Goddard Space Flight Center has responsibility for the TSIS-1, and is set to continue developing, operating, and troubleshooting the craft for at least five more years. The data gathered is to be placed in NASA’s archive and distribution system, so it is widely available for the entire scientific community to study.