Engineering topics
Roelke, Evan
Publications and source records attributed to Roelke, Evan.
SmallSat aerocapture to enable a new paradigm of planetay missions
This paper presents a technology development initiative focused on delivering SmallSats to orbit a variety of bodies using aerocapture. Aerocapture uses the drag of a single pass through the atmosphere to capture into orbit instead of relying on large quantities of rocket fuel. Using drag modulation flight control, an aerocapture vehicle adjusts its drag area during atmospheric flight through a single-stage jettison of a drag skirt, allowing it to target a particular science orbit in the presence of atmospheric uncertainties. A team from JPL, NASA Ames, and CU Boulder has worked to address the key challenges and determine the feasibility of an aerocapture system for SmallSats less than 180kg. Key challenges include the ability to accurately target an orbit, stability through atmospheric flight and the jettison event, and aerothermal stresses due to high heat rates.
Understanding International GNC Hardware Trends
An industry-wide survey of guidance, navigation and control (GNC) sensors, namely star trackers, gyros, and sun sensors was undertaken in 2014, in which size, mass, power, and various performance metrics were recorded for each category. A multidimensional analysis was performed, looking at the spectrum of available sensors, with the intent of identifying gaps in the available capability range. Mission types that are not currently well served by the available components were discussed, as well as some missions that would be enabled by filling gaps in the component space. This paper continues that study, with a focus on reaction wheels and magnetometers, as well as with updates to the listings of star trackers, gyros, and sun sensors. Also discussed are a framework for making the database available to the community at large, and the continued maintenance of this database and the analysis of its contents.