This puff piece on Marshall contains a troubling assertion…one which needs to be knocked down before it becomes widely accepted as the gospel truth:
Work to find a propulsion system for a ship to travel through the solar system, a Mars ship, has been underway for the past few years. Using chemical rockets like those that powered the Saturn Five and the Space Shuttle aren’t feasible for a Mars trip. Using cumbersome chemical rockets would make a Mars ship 95% fuel, and the round trip would take nearly two years. What’s needed is something more efficient, and at the Propulsion Center, that something may be electric propulsion.
Someone at Marshall is obviously looking for funding for their pet project, by positioning electric propulsion as a sine qua non for manned exploration of Mars.
Electric propulsion is not needed for manned missions to Mars. Currently available chemical propulsion technology will get humans to Mars in 5-6 months. While it’s sensible to explore long-term advanced propulsion technologies, delaying manned expeditions by another decade and spending tens of billions of dollars on propulsion R&D so that we can shave maybe a month off of the transit time is foolish when we have a serviceable alternative available to us today. As others have noted, it’s akin to asking Columbus to wait to cross the Atlantic until steam-turbine ships became available.