president’s budget request.
Every administration retasks NASA to build their own enduring science legacy in a fifteen year plan, cancelling the grand plans of their predecessors to move their achievements out of the potential shadow of the former administration. And then Congress prevents it. And then four or eight years later the weak compromise is cancelled by a new administration to put their stamp on a new enduring science legacy...
By the time NASA gets men to Mars, on arrival they will be having an espresso at the Starbucks on the patio at Musk Interplanetary Spaceport #4.