Fast 2-impulse non-Keplerian orbit transfer using the Theory of Functional Connections Allan K. de Almeida Junior, Hunter Johnston, Carl Leake and Daniele Mortari Eur. Phys. J. Plus, 136 2 (2021) 223 Published online: 17 February 2021 DOI: 10.1140/epjp/s13360-021-01151-2