It is hoped that humans could colonise the moon and spacecraft powered by steam will be the way to do it. Cheap fuel could come from the ice water in asteroids and unlike when using steam power on earth, the steam would push the item forward. Reaching Mars is out of the question at present, but due to low gravity, a very little effort will be needed to push the craft forward when it happens.
Robots are going to be used to look for the water and they will be controlled from Earth, and in time, people will be able to live there. Knowing that spacecraft can stop will reduce the cost of any trips that are made to Mars. At present everything, a craft needs must be loaded at the beginning, but in the future 68% less mass would be necessary if refuelling was available.
The savings are attractive but everything must be safe. It is the weight difference that will save a lot of fuel and as it is stated that hydrogen and oxygen can be collected on the moon, it can be stored and used for refuelling.