Helical Engine
https://ntrs.nasa.gov/search.jsp?R=20190029657
Characterization of a Non-Stationary Spherical Inflated Light Sail for Ultra-Fast Interstellar Travel by Using Commercial 3D Codes
https://www.researchgate.net/publication/328028194_Characterization_of_a_Non-Stationary_Spherical_Inflated_Light_Sail_for_Ultra-Fast_Interstellar_Travel_by_Using_Commercial_3D_Codes
The Problem of Identifying Possible Signals of Extra-Terrestrial Civilizations in the Framework of the Information-Based Method
https://www.scirp.org/html/1-1721672_95549.htm
Solar sailing technology challenges
https://www.sciencedirect.com/science/article/abs/pii/S1270963818314391
Phosphine as a Biosignature Gas in Exoplanet Atmospheres
https://arxiv.org/abs/1910.05224