“…Proposals exist for missions that are prepared and wait in storage for the discovery of a suitable object, either on Earth, or the sun-earth L2 point. Even though fly-by missions are significantly easier, a lander using solar-electric propulsion could be feasible (Hein, Eubanks, et al 2022). A landed mission would bear similarity to Philae on the ESA Rosetta mission and could do seismic or acoustic investigations to constrain subsurface properties either during landing Biele et al 2015 or by listening to seismic waves excited during operation of a drill or similar instrument (Knapmeyer, Fischer, Knollenberg, Seidensticker, Thiel, Arnold, Schmidt, et al 2016;Knapmeyer, Fischer, Knollenberg, Seidensticker, Thiel, Arnold, Faber, et al 2018).…”