Here is the option I promoted to the Augustine Commission:
NASA pay Boeing or SpaceX to send crew to the ISS until 2015, upon which they hand over the station to Boeing, pleasing scientists, taxpayers, international partners, and dreamers everywhere.
NASA cut the shuttle in early 2011
NASA ask Russia or Europe to build heavy launch vehicles to loft surface system elements
NASA build planetary surface elements
NASA sends people and surface systems to Mars, with people launched on commercial vehicles and systems launched on International Partner rockets.
Now it’s your turn.