MEGA Drive, in phase two testing, could power not only local travel within our solar system but also interstellar travel

https://oilprice.com/Energy/Energy-General/A-150-Year-Old-Idea-Could-Lead-To-A-Breakthrough-In-Space-Travel.html

See also: What Is the Mach Effect Gravity Assist or Mega Drive?

https://owlcation.com/stem/What-is-the-Mass-Effect-Gravity-Assist-or-MEGA-Drive

"Woodward and Fearn have sent their design to 4 different labs which have tested the drive and confirm that there is something happening here. NASA has even contributed 2 grants to further study the drive. Results show that the mass is changing in conjunction with the piezoelectric activity, and so the thrust generated, while small, is present. Very, very promising"

Related: Dynamic soaring as a means to exceed the solar wind speed

https://www.frontiersin.org/articles/10.3389/frspt.2022.1017442/full