The Observatory: Satellite Solutions and Resolutions
The Observatory is a weekly series that brings together students, alumni, and professionals associated with OSU Battelle Center to write about topics that are relevant to the mission of our center. Our guest writer this week is OSU Battelle Center Alum, Bryan Ahn. Bryan graduated in May 2020 with a Master’s Degree in Aeronautical and Astronautical Engineering and currently works as an Opto-Mechanical Engineer for Satrec Initiative, a satellite manufacturer and image service provider in South Korea that is developing world-class, high-performance satellites for Earth observation. Bryan has a passion for advancing Korea’s space industry and solving humanitarian issues around the world through remote sensing.
The Earth observation satellite industry is changing. When Planet announced a new satellite factory in September 2018 capable of producing up to 40 Dove satellites per week, they disrupted the entire industry. With their agile aerospace vision, they achieved their goal of producing high-performance optical satellites at scale and multiplying their satellite constellation. This past September, almost exactly two years after Planet’s announcement, Seattle-based company BlackSky announced plans to produce 18 satellites in two years for their constellation mission.
The quality of space-based imaging can be determined by the following three types of resolutions: spatial (image resolution), spectral (the range and density of the light spectrum captured), and temporal (how frequently the same scene is imaged). Spatial and spectral resolution can be improved by creating larger satellites or by using more powerful imaging sensors. To address temporal resolution, however, one must increase quantity. Recently, satellite manufacturing companies have been able to rapidly produce small satellites, as demonstrated by Planet and BlackSky. Through the use of agile aerospace philosophies and assembly-line-type manufacturing processes, they have been successful in rapidly adding satellites to their constellations. However, their ability to produce satellites at scale comes at a cost — they sacrifice spatial and spectral resolution.
BlackSky’s constellation currently has a 1-m spatial resolution and Planet’s SuperDove satellites have a value of 0.5-m. While these spatial resolutions are great, they are not the best. Production speed is certainly a competitive advantage, but certain customers require the highest level of spatial and spectral resolution even if production speeds are much slower. Some of the most powerful satellites today, such as Satrec Initiative’s SpaceEye-T model, can image the Earth at a spatial resolution of 30 cm! Different applications yield different satellite designs.
The next big leap would be to mass-produce satellites that perform exceptionally across all three resolution categories. Is this even achievable? The industry certainly is trending in that direction. But by then, there may be satellites capable of imaging Earth at the sub-centimeter level.
