first thing u wanna do is get to neptune,
then u must goback to earth
rules:
1.Earth - orbit : using default engine
2.Orbit-neptune: its up to u
3. Neptune orbit-earth : ion/electric engine thingy
4.u can do launch pad assembly
first thing u wanna do is get to neptune,
then u must goback to earth
rules:
1.Earth - orbit : using default engine
2.Orbit-neptune: its up to u
3. Neptune orbit-earth : ion/electric engine thingy
4.u can do launch pad assembly
Efficient. All you need is an efficient rocket to take you there.
There's no minimum payload weight so this shouldn't need launchpad assembly, even if you're not using ion engines. Getting there shouldn't be much harder than a Venus trip with a bit of gravity assist going on, aerobrake capture into Neptune SOI.
Not sure where in Neptunes SOI you're intending on people going or if they even have to stop by, at which a free return flight should get you back without any problems and then a parachute controlled landing on Earth.