Jeff Thayer: Coupling Astrodynamics and Remote Sensing to Study Geosciences

When CCAR was founded by Dr. George Born in 1985, its focus was in the traditional astrodynamics fields of navigation and orbit determination. Over the years, the center’s research focus has evolved to encompass broader research topics, such as geoscience and  the observation of the Earth system by remote sensing techniques. Dr. Thayer explains:

“Once you determine precise orbital techniques, it is a natural progression to look into remote sensing of the Earth. We’ve made [remote sensing] a focus for the geosciences, allowing us to study the cryosphere, hydrosphere and ionosphere.”

NASA’s Gravity Recovery and Climate Experiment (GRACE) ideally demonstrates the connectivity between astrodynamics and geoscience research. GRACE consists of two twin satellites orbiting the Earth. By knowing their precise location in relation to each other (astrodynamics), researchers can determine perturbations in Earth’s gravity field. These perturbations can be linked to the distribution of mass on Earth’s surface, indicating global movements in water and land ice (geosciences).

Remote sensing, in of itself, is an extremely diverse field. Dr. Thayer has focused on the use of Lidar and radar in his research of the aerospace environment of Earth’s atmosphere and geospace. Currently, Dr. Thayer is investigating improved techniques for measuring and predicting Earth’s atmospheric density, allowing for improved prediction of low-earth orbit (LEO) satellite drag. Due to its dependence on solar activity, atmospheric density at LEO can vary by an order of magnitude. The accurate calculation of atmospheric density, and thus satellite drag, is essential for the effective identification and avoidance of possible satellite collisions.

Dr. Thayer notes that one of the most incredible aspects of CCAR as an institution is its “capacity to go from cradle to grave of an entire space mission.” Because of their abundance of space expertise and research infrastructure, CCAR has become intimately involved with major governmental panels, such as the IPCC (Intergovernmental Panel on Climate Change), and NASA missions, such as OSIRIS REx (Dr. Dan Scheeres) and COSMIC II (Dr. Penina Axelrad).  The center has even been sought out for mission design by international entities, including the United Arab Emirates (Dr. Jeff Parker).

Not only does CCAR provide students with invaluable research opportunities; it provides them with a sense of identity. Dr. Thayer comments, “The topic of aerospace is broad. CCAR gives students more of a sense of identity in terms of the research they want to pursue, while also involving them with a community of students with common interests.”

 

Though founded three decades ago, the research conducted through CCAR still holds imminent relevance today. With every passing year, our society grows inceasingly dependent on space-based technologies for telecommunications, navigation, terrestrial and interplanetary research, and more. It is essential for the sustainability and growth of these systems that we understand the space environment in which we interact.  

-Written By: Ari Sandberg, Intern