Key Radar Antenna Stuck on Europe’s Jupiter-Bound Spacecraft

A 1:18 scale model of the Juice mission's RIME antenna—Radar for Icy Moons Exploration, mounted on top of a simplified spacecraft model during tests in the Hertz facility at the European Space Research and Technology Centre (ESTEC) in Noordwijk, The Netherlands, in an undated photo. European Space Agency via AP

CAPE CANAVERAL, Fla.—A critical antenna is jammed on a Jupiter-bound spacecraft launched two weeks ago, the European Space Agency reported Friday.

The 52-foot (16-meter) radar antenna on Juice unfolded only one-third of the way following liftoff, according to the space agency.