What happened with Operation Highjump?

In 1946, barely a year after World War II had drawn to a close, the US Navy set sail with an impressive fleet.  A total of 13 ships in all with 4 of them being combat ships and the others transport and support, headed due south to Antarctica.  A contingent of troops were also aboard the transports, bringing the total of US personnel to 4,700 men.  The entire task force was under the command of the legendary Rear Admiral Richard Byrd.  Four men were lost to "accidents."  The mission ended early, six months after it began.  Why did any of this take place?
The reason given by military officials was so that soldiers and sailors could become accustomed to operating in polar conditions.  Additionally, military strategists were said to be testing the practicality of building and maintaining Antarctic bases for the long term.  
This sounds reasonable and I think quite likely, but the hazy nature of Highjump's planning and execution has become fertile ground for the growing of conspiracy theories.  Consider the following:

1) The mission was oddly timed.  Why did the Navy and Admiral Byrd see an urgent need to expend such considerable resources just after coming out of the bloodiest conflict in human history?
2) Even after the end of the war, a handful of German U-boats were either captured or sunk.  Enormous stores of mercury were found in the cargo holds of these submarines.
3) The Germans had a known and documented outpost in Antarctica. It was called "Neu Schwabenland."
4) Finally, Byrd is rumored to have made a rather cryptic quote, that America needed to defend itself from advanced aircraft that could travel from pole to pole in no time.  I remember reading this juicy nugget, but in my search for a link to a source citing it, I've been unsuccessful.  Guess that says something about its validity.

From these enigmas, fringe theorists began to connect a few of the conspiracy dots.  Indeed the Germans were in the process of building very advanced aircraft at the end of the war with a few of them even planned to travel into space.  A few of the designs were saucer shaped.  They were also said to have been mercury powered.  If mercury is placed inside a glass orb and spun at high velocity, it begins to lift and to emit light.  This might account for the glowing orbs that WWII pilots reported as "foo fighters."

So here's how the "untold" story of Operation Highjump is supposed to have unfolded.  US forces traveled to the South Pole to dislodge the last vestige of Nazis because they were in possession of superweapons.  Things can be taken further, such as Hitler survived the war and fled to Antarctica, there was UFO technology involved (Hitler was a big believer in aliens) and maybe even the Hollow Earth.
That reads like great fiction, but it doesn't entirely add up.  For one thing, I would think that there would have been many more casualties than four men if we were fighting so-called "wunderwaffens," or wonder weapons.  Also, you would think that someone involved in the operation would have talked by now.  As for the seeming urgency of the mission, it was probably in response to what Washington saw as the growing Communist threat.   
So for my money, Highjump was just a military exercise.  But wouldn't it be wild if it was really something else?
You can read more about the "alternative theories" here.
The pic above is from the site.

Addendum: There will actually be an Operation Highjump video game.  It is to be tied in with the release of the upcoming, uber-cool looking move Iron Sky, which involves Nazis on the Moon.  Here's the link to a description and how can you not like their graphic?

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