Source for the US denying water on mars? You can detect water on mars with a telescope in your back yard, if you can see the northern hemisphere of mars. The entire northern ice cap (or most of it anyway) is water ice. Southern ice cap not so much, but the north has tons of water. We knew about this before Mariner. How to tell whether that white spot on the surface of mars is water ice or not is left as an exercise to the reader.

So the mistake in using imperial units this time would result in a soft landing?

Christmas on Mars, due out in 2003!