On 16th August 2024, SpaceX launched into space the most cutting-edge thermal infrared satellite in existence. The satellite was Hydrosat’s Van Zyl-1 (VZ-1) cubesat, which is at the forefront of technology not because it is a billion dollars, large and complex instrument, but rather the opposite: it is one of the smallest, least energy-intensive, and lowest cost instruments ever built for high resolution thermal infrared Earth Observation. What this enables Hydrosat to do is launch a lot of these sensors into a constellation for global monitoring of the temperature of the planet at high resolution, every day. This data can help us track forest stress for wildfire susceptibility, crop water demand for irrigation optimization, urban heat for public health and environmental justice, energy structures of hurricanes to forecast trajectory, and scores of other applications all intensifying under climate change.
I am the Science Lead for Hydrosat, but not too long ago I was a Linacre JRF, getting my gym workouts in the basement and eating far too many potatoes in the dining hall. I had come to Oxford as a postdoc to work with Yadvinder Malhi, developing components for the UK climate model and going into the Amazon and Andes for weeks (as Yadvinder’s team tends to do) to conduct a nutrient fertilisation experiment; I had the pleasure of working with Nick Brown on a few papers along the way. In 2010, I cut my JRF short to take up a position as a NASA scientist at the Jet Propulsion Laboratory (JPL) in California. At JPL, I became the Science Lead for a mission called ECOSTRESS, which we launched to the International Space Station. ECOSTRESS has been transformative for Earth Science. Members of Yadvinder’s academic family came together recently to use these data to identify critical temperature thresholds of tropical forests; our paper made the cover of Nature last year.
The Hydrosat VZ- 1 satellite was named after one of Hydrosat’s founders, Dr. Jakob Van Zyl. Originally from Namibia, Dr. Van Zyl’s career took him to Caltech for a Ph.D. then on to NASA JPL, where he quickly rose to Associate Director of JPL for Strategy and Director of Solar System Exploration. I overlapped with Dr. Van Zyl at JPL for almost a decade, though he was so high up the ladder that I never directly worked with him. It was to my surprise in 2019 that after 33 years at the top of the JPL career ladder, Dr. Van Zyl left JPL. I wondered what could have been so much better than the top of JPL to inspire him, especially as I was still early in my career ascension at JPL. It was to co-found Hydrosat. His vision was to accelerate Earth science technology and missions, cutting through governmental funding limitations and bureaucratic constraints, and to strengthen the connection between data and applications. He wouldn’t know it then, but his vision succeeded.
Tragically, just a year after co-founding Hydrosat, Dr. Van Zyl was taken from this planet, passing away in August 2020. This should have been the end of Hydrosat. But, his spirit was strong, and the remaining Hydrosat co-founders regrouped and forged ahead. It was they who thought to honor Dr. Van Zyl through the naming of the satellites. Today, Hydrosat is rapidly growing with team members distributed throughout the world. Hydrosat makes or breaks on its ability to help people, and we have been thriving as evidenced by our growth.
I joined Hydrosat as the Science Lead in August 2021, exactly one year after Dr. Van Zyl’s death. I recognised that Hydrosat technology was more advanced than what we were doing at NASA, specifically for getting us to a constellation of satellites. As I started exploring my role within Hydrosat, I realised there was a void to fill from Dr. Van Zyl’s departure. I soaked up everything I could from what he left behind in papers, presentations, and other documentation, trying to get a feel for what he had been thinking, and how he had been thinking. Although I regret never having had the chance to work directly with Dr. Van Zyl, in many ways I am working with him very closely. At the Hydrosat launch, CEO Pieter Fossel gave a stirring speech about the many trials and tribulations along the way that got us to where we were that day, thanking and recognising everyone who led and contributed to the success. He gave a moving dedication to Dr. Van Zyl, with Dr. Van Zyl’s wife in attendance. I went up to her afterwards to introduce myself, affirming to her that I and others were carrying her husband’s torch forward; she collapsed into my arms with emotion.
The launch marked a huge milestone for Hydrosat as we had been building towards this moment for many years, underscoring an exciting future from the engineering and commercial legs that comprise the company. But, more importantly, Hydrosat has accomplished an incredible milestone of humanity, within the team and its extended family—its heart—which is just a microcosm of the overall mission of engaging and helping the humanity of the planet overall. We are here to help the world carry the torch forward.
Dr. Joshua B. Fisher with the Hydrosat satellite being launched on a SpaceX rocket in the background.
Hydrosat’s engineering enables a constellation of satellites that provides daily high resolution thermal infrared data globally.
