It's ambitious that's for sure.
The space station has always been a factor for ease of use missions to Mars and the Moon. The concept is the same as having a waypoint from which to lower cost of launches and craft sizes by making them space ships and not space ships on rockets. That's why the ISS is so important to future plans. De orbiting before we've returned to the moon or tried to go to Mars is one of those big waste of money that I'm always complaining about with NASA and the Government. We'd have to build it all over again and it would cost even more money. It's about time this country learned a few things from Russia on how to low cost achieve and maintain a presence in space for 40 years with out breaking the bank on Rocket Designs.
It's this kind of thinking that had us roaming the stars by the 23rd Century.