Technical limitations Future of space exploration

the vasimr plasma based propulsion engine

in terms of propulsion, main challenge liftoff , initial momentum, since there no friction in vacuum of space. based on missions goals, including factors such distance, load , time of flight, type of propulsion drive used, planned use, or in design varies chemical propellants, such liquid hydrogen , oxidizer (space shuttle main engine), plasma or nanoparticle propellants.

project longshot nuclear fission engine schematic

as future developments, theoretical possibilities of nuclear based propulsion have been analyzed on 60 years ago, such nuclear fusion (project daedalus) , nuclear pulse propulsion (project longshot), have since been discontinued practical research nasa. on more science fiction side, theoretical alcubierre drive presents mathematical solution “faster-than-light” travel, require mass-energy of jupiter, not mention technical issues.