Short answers, pulled from the story.
A radome is a weatherproof enclosure built from materials transparent to radio waves, designed to protect a radar antenna from ice, wind, and debris. The word is a portmanteau of 'radar' and 'dome.' Radomes also conceal the electronic equipment inside from outside view and protect nearby personnel from contact with quickly rotating antennas.
Radome use dates back to 1941. In 1948, Walter Bird built the world's first pneumatic radome at the Cornell Aeronautical Laboratory, a dome held rigid by air pressure alone that was also the first pneumatic construction of any kind in history.
A rotodome is a discus-shaped radome that rotates on top of an airborne early warning and control aircraft's fuselage to provide 360-degree radar coverage. The American E-3 Sentry is among the aircraft fitted with this design.
RAF Menwith Hill uses radomes to protect its surveillance antennas and to prevent outside observers from determining which direction the antennas are pointing. Knowing an antenna's direction would reveal which satellite it is targeting, so the radomes deny that information to anyone outside the perimeter.
Large cruise ships and oil tankers may carry radomes over 3 m in diameter to protect antennas that track satellites continuously while the vessel pitches, rolls, and yaws. At the smallest end, private yachts use radomes as little as 26 cm in diameter for voice and low-speed data.
The radome at Pleumeur-Bodou, France, was built in 1962 to protect the PB1 antenna, which received mondovision television transmissions from the Telstar satellite relayed from the United States. The Pleumeur-Bodou radome has since become a museum; its American counterpart was dismantled along with the antenna it once protected.