Leveraging the expertise of the Cockrell School of Engineering’s Center for Space Research and Texas Spacecraft Laboratory, an international team of engineers and scientists are embarking on a three-year project to develop a new nanosatellite dedicated to gravimetric and thermospheric density studies.
Byron Tapley and Brandon Jones, faculty members in the Department of Aerospace Engineering and Engineering Mechanics, will join the Portuguese aerospace company Spin.Works as well as the Iberian Nanotechnology Laboratory, Instituto de Soldadura e Qualidade and the University of Minho to build the nanosatellite. Spin.Works is leading the project.
Tapley established the Center for Space Research in 1981 in collaboration with NASA and served as the director for 46 years. For over 15 years, the center’s Gravity Recovery and Climate Experiment (GRACE) has gathered valuable gravimetric data that is used to monitor the geophysical mass-transport processes taking place on Earth’s surface. The GRACE Follow-On mission (GRACE-FO) was launched in 2018 to continue this essential monitoring of Earth’s changing climate through gravimetric data that quantifies ice-sheet mass loss in places like Greenland and West Antarctica, characterizes the water cycle at regional scales and observes gravitational changes resulting from the displacements created by large earthquakes. The accelerometers on board these satellites also allow for the estimation of the density of the neutral thermosphere, which enables the improvement of drag models and the study of the sun-Earth interaction though the measurement of thermospheric cross-winds.
The micro-Prototype for Gravity Recovery and Assessment via Distributed Earth observation (uPGRADE) will follow on the footsteps of NASA's GRACE and GRACE-FO. The mission aims to develop a spacecraft only 1/1000 the volume of its' predecessors and at about 1/100 of the cost.
The main scientific instrument of the mission is a new microelectromechanical-system-based high-precision accelerometer capable of measuring extremely small accelerations acting on the spacecraft at orbital altitudes, a development led by the Iberian Nanotechnology Laboratory and the University of Minho, which will be fully developed and qualified for operation in space through uPGRADE. This device will then be integrated along with a commercial off-the-shelf GNSS receiver and two miniaturized star trackers placed in a customized, highly rigid nano-satellite configuration to be developed at Spin.Works. These compact configurations are typically necessary in gravimetric missions to ensure non-gravitational accelerations, including atmospheric drag and solar radiation pressure, can be measured by the accelerometer to ensure the gravitational signal can be separated. Only then does it become possible to "see" how the Earth's gravity field itself changes over time on regional scales.
Along with the platform development, Spin.Works will be responsible for the systems Attitude and Orbit Control System (AOCS) and the development, space qualification and preparation for small-scale manufacturing of two other key system components — the spacecraft's on-board computer and star trackers.
The UT Austin team will support the project in two main areas: satellite engineering and science application. On the engineering side, Tapley and Jones will support Spin.Works with the Texas Spacecraft Laboratory’s vast expertise in CubeSat design and integration. On the aspects of application, the Center for Space Research will focus on supporting the design decisions that affect the quality of the data gathered by the GPS receiver, star trackers and accelerometer, as well quantifying the science impact of the satellite.
uPGRADE is one of 11 collaborative research projects through the UT Portugal program that recently received funding through the Go Portugal: Global Science and Technology Partnerships Portugal initiative from the country’s Ministry of Science, Technology and Higher Education
