There will be expected and unforeseen problems. The DST will only go to the orbit of Mars, which means that a large lander, capable of making soft touchdown on the Red Planet, would have to be built in space. NASA's key contractor, Lockheed Martin, proposed a giant space plane, which would use the SLS rocket for launch from Earth. Then there is the newly emerged juggernaut of space business, SpaceX, which hopes to build the Big Falcon Rocket, BFR, to haul into Earth's orbit a 150-ton trans-Martian cruiser with 40 crew cabins. To escape the Earth's gravity, the huge ship would need four refueling tankers and another refueling on Mars using a prebuilt propellant production plant. How would going back to the moon help?