Seven years - much longer than expected - the Belgian satellite PROBA-V has been monitoring our global land surface every day. Today, June 30th, marks PROBA-V’s final day as one of ESA’s operational satellite mission with a focus on agriculture, climate and vegetation. Comparable images will continue to come, but from now on via the European Sentinel-3 satellites of the European Space Agency (ESA).
Mol, June 30, 2020 – If you want to get a clear view on how our planet is changing or what the effects are of climate change, you need objective and comparative data over a longer time span. The Flemish research centre VITO has more than 20 years of experience in processing Earth observation data. It started in 1998 with the collection and processing of satellite images from the SPOT VEGETATION satellites that stopped in 2013 and 2014. From the beginning, BELSPO (Belgian Science Policy Office) has been the driving force behind it. In May 2013, PROBA-V was launched in anticipation of the Sentinel-3 satellites. Initially foreseen to monitor our Earth’s land surface for 2.5 years. The small Belgian satellite provided us with much more, but after seven years PROBA-V’s lighting conditions are less favorable.
The PROBA-V satellite is not bigger than an oversized washing machine. It was known from the beginning that PROBA-V wouldn’t have a long life expectancy. PROBA-V was initially conceived as a gap filler between the SPOT-VGT (1998 – 2014) and Sentinel-3 missions, with a maximum designed lifetime of 5 years. The satellite is also one of the last satellites sent into the universe without propulsion. Propulsion doesn’t only ensure more control over the route the satellite follows, but it also gives the opportunity to perform manual interventions when the satellite approaches another object in space for instance.
However, the importance of the images transmitted by the PROBA-V satellite is almost immeasurable. Monitoring our Earth at an altitude of 825 kilometres, covering an area of 2,250 kilometres fourteen times each day, the satellite was able to monitoring the planet’s entire land surface. The ideal timeslot for PROBA-V to acquire images is between 10 and 11h because of best lighting conditions and less clouds. Due to the expected satellite drift, the overpass time (today 9:20) is declining rapidly, making the acquisitions gradually unusable.
Yet PROBA-V surprised many scientists. The large amount of images provided by the satellite over the past 7 years remain available. The platform is also in extreme good condition. It would be pity to not use this technology for other purposes. That is why PROBA-V is entering an experimental afterlife that will continue through October 2021. We will continue to provide valuable observations over Europe and Africa at 100 m, 300 m, and 1 km resolution to perform various scientific experiments, including calibration purposes for other satellite missions. PROBA-V will continue to circle the Earth and it is not even inconceivable that it can be used again in about seven years' time when it starts to come into the light on the other side of the Earth. Theoretically it is all possible, only the future will tell if this scenario will come true.
The data of its successor, Sentinel-3, will also be made available by VITO via the new Terrascope platform. With the online platform Terrascope, VITO makes open-source satellite images easily accessible to all users, free of charges.
