Nieke Roos
9 May 2019

The Dutch space instrument for aerosol measurement, Spexone, has been greenlit. The Netherlands Space Office has awarded the project 7 million euros, which completes the funding that’s needed for the instrument’s production. Spexone will be jointly developed by SRON Netherlands Institute for Space Research and Airbus Defence and Space Netherlands, supported by experts from TNO and Dutch SMEs. Onboard NASA’s Pace satellite, scheduled for launch in 2022, it will map the amount and properties of aerosols with an accuracy never seen before, providing new valuable data to climate scientists.

Aerosols are small, airborne dust particles, such as soot, ash and desert dust, also known as particulates. They have a major influence on air pollution and climate change, but their precise role is insufficiently known. For example, most aerosols reflect light and have a cooling effect on the earth, but they can also have a warming effect due to absorption. “We don’t know exactly how many there are in the atmosphere, what properties they have and what their precise effect is on radiation and cloud formation,” says the principal investigator for Spexone, Otto Hasekamp of SRON.

Next to the Spexone aerosol polarimeter, NASA’s Pace satellite will be harboring the OCI ocean color instrument and the Harp-2 cloud polarimeter. Image: NASA GSFC

Weighing less than 10 kg, Spexone gives researchers unprecedented insight into the properties of aerosols, such as size, composition, shape and absorbent capacity. The spectropolarimeter accurately maps out the properties that cause warming or cooling by measuring the extent to which sunlight is polarized when reflected by the earth’s atmosphere in the direction of NASA’s Pace satellite (Plankton, Aerosol, Cloud and Ocean Ecosystem). This observatory studies the various factors that affect the climate. Next to Spexone, it harbors NASA’s Ocean Color Instrument (OCI) – the main instrument – and the Hyper-Angular Rainbow Polarimeter (Harp-2), provided by University of Maryland, Baltimore County (UMBC).

Spexone is made possible by a Dutch investment of 14 million euros, including a total of 9 million from the Netherlands Space Office. Other funding comes from the Netherlands Organization for Scientific Research (NWO), SRON and Airbus Defence and Space NL. The latter two are responsible for designing, manufacturing and testing the instrument. TNO is supporting them with its optomechanical expertise. The project partners can benefit from the knowledge that they’ve gained from another joint Dutch effort, Tropomi (link in Dutch), the atmospheric instrument on the EU’s and ESA’s Sentinel-5 Precursor satellite.