At NASA's Goddard Space Flight Center in Maryland, the climate satellite PACE was waiting on her first measurement instrument when on June 8, a group of Dutch and American engineers walked into the cleanroom. SPEXone, together with the instruments HARP2 and OCI, will provide the spacecraft with a razor sharp view of the Earth to measure the color of its oceans and map the properties of aerosols. The Dutch SPEXone instrument—developed by SRON and Airbus Netherlands with support from TNO—is responsible for the aerosol measurements together with HARP2 and is now the first instrument to be integrated on the satellite.

Aerosols are small dust particles in the air, such as soot, ash and desert dust. They have a major influence on air pollution and climate change, but their precise role is insufficiently known. That is why scenarios for global warming up to the year 2100 vary by approximately 3 degrees Celsius. Most aerosols reflect light and have a cooling effect on the Earth, but they can also have a warming effect due to absorption. SPEXone will map out the properties of aerosols, such as size, shape, composition and absorbing/reflecting power. It also helps the OCI instrument to measure the color of the oceans and thus monitor the amount of plankton. This is because a correction is necessary due to aerosol scattering.