Engineering topics
Boone, Dylan R.
Publications and source records attributed to Boone, Dylan R..
Preliminary Saturn Atmospheric Density Results From Cassini's Final Plunge
The Cassini spacecraft made its final descent into the planet Saturn on September 15, 2017, capping a twenty year mission full of scientific discoveries. The high gain antenna was held on Earth-point until torques from atmospheric drag caused the spacecraft to lose line-of-sight lock with Earth. The Doppler data collected during the final plunge contains information about the spacecraft’s acceleration due to atmospheric drag, and therefore, the density of Saturn’s atmosphere. In this work, we present preliminary analysis of the end of mission Doppler data and its implications regarding the density of Saturn’s upper atmosphere. Are construction of the spacecraft’s final trajectory is discussed and used to fit a model of Saturn’s atmosphere to the Doppler data taken during the final plunge. The Cassini navigation team’s experience flying the spacecraft through the final five low altitude Saturn periapses is also discussed in the context of atmospheric drag and density models.
Orbit Determination Sensitivity Analysis for the Europa Multiple Flyby Mission Concept
This paper details the results of parametric variations on the notional Europa Mission Concept tour navigation strategy on orbit determination delivery and knowledge errors and the associated statistical ∆V consumption. Approach maneuver placement at encounter minus two and a half days and at encounter minus three and a half days is compared to the reference encounter minus three days location as well as variations to the data cutoff for approach maneuver design, which is baselined one day prior to maneuver execution. An execution error model with fixed and proportional components assigned to the magnitude and pointing directions is applied to each maneuver in a Monte Carlo simulation. Variations on the fixed and proportional contributions to both component errors are simulated and analyzed to show the effect of varying thruster characterization levels. The effects of varying levels of a priori satellite ephemeris errors are also characterized in this study.