Definition of "umbilicus"

The importance of the visual analyzer is further increased when the cosmonaut is in free space with only the slight support of an umbilicus.

1966, Aerospace Technology Division, Soviet Biotechnology and Bioastronautics: Report, Library of Congress, page 10

Penetrators will be connected by an umbilicus to an afterbody containing imaging and meteorological instruments.

1977, James W. Head, United States. National Aeronautics, Space Administration, Significant achievements in the planetary geology program, 1975-1976

How about a 270 mile tether to an orbiting satellite? Oh, you'd like that, wouldn't you? Frank! Prepare to receive the umbilicus!

1994, Michael J. Nelson (head writer), "Girls Town", episode 601, Mystery Science Theater 3000

Ninety minutes into the twenty-six hour flight, Leonov opened the outer hatch and pushed himself out to the end of his 17-foot umbilicus — becoming the first man to walk in space.

2013, Treion Muller, Matthew Murdoch, The Webinar Manifesto: Never Design, Deliver, or Sell Lousy Webinars Again!, RosettaBooks

The ends of the umbilicus were called cornua (i.e. horns) in Latin, and were usually adorned with some pretty device

1763, William Massey, The Origin and Progress of Letters