The contrarian opinion is to increase budget 100X, construct Helium-3 mining colonies on the lunar surface, and deploy rocket foundries for missions to Titan and beyond ;)

http://www.moonexpress.com/

Direct Fusion Drive For A Human Mars Orbital Mission

https://bp.pppl.gov/pub_report/2014/PPPL-5064.pdf

Future Chinese Lunar Missions

https://nssdc.gsfc.nasa.gov/planetary/lunar/cnsa_moon_future...