Designing A Flying Saucer

What kind of landing craft would we need if we were contemplating a visit to a strange new world?

As I write this, the news reports are full of talk about ‘UFOs’ being shot down by the US air force, and while there is currently no indication or evidence that these objects are extra-terrestrial in origin, the idea has thrown up an interesting engineering challenge.

Let’s pretend for a moment that aliens have flown 400 light years to pay us a visit. If…