Just before Christmas, Bruce McCandless II died.  In 1984, during one of his two Space Shuttle missions, McCandless made the first untethered free flight in space, using the manned manoeuvring unit (MMU).  He was a tentative Iron Man.

McCandless was one the Original Nineteen, selected in 1966 by NASA for possible Apollo missions.  Because he was primarily a scientist, he failed to get a place on an Apollo mission (the programme favoured candidates with extensive test pilot experience).

But he was, vitally, a ‘CAPCOM’ for Apollo 11.  The CAPCOM’s role was rostered responsibility for sole verbal communication with the Apollo crew whilst they were in space.  Astronauts would address CAPCOM team members as ‘Houston’, as in ‘Houston, this is Tranquility Base; the Eagle has landed.’

The image of McCandless, piloting the MMU during his Shuttle mission, when he finally got to space, could hardly be more iconic.  It is of a human-shaped form, having stepped through the door, floating in a most peculiar way.  It is especially powerful because McCandless’ face is not recognisable behind the reflective visor.  In a bulky suit that allows the crudest expression of a human physique – head, torso and limbs – he is Everyman and Everywoman.

It’s a second incarnation of Leonardo’s Vitruvian Man, based on correlations of human proportions with geometry described by Vitruvius in Book III of De architectura.

When the planetary probe Voyager II left Earth in the seventies, the original Leonardo image was closer to defining our image to our distant neighbours in the cosmos, because it was engraved on the gold disc carried aboard. Voyager II is the first spacecraft from Earth in interstellar space.

Who knows whether McCandless’ image or Vitruvius’ is closer to what Aliens will encounter first.  If Elon Musk and Jeff Bezos and other commercial Astronauts (literal translation: ‘star sailors’) have their way, scattering us to Mars and then beyond, I’d bet on Bruce McCandless II, a relatively unknown pioneer and adventurer, who first cut the cord from Mother Earth.