Assertion: trident's missile | /r/HasProperty | followed
Facets:
value: by beginning in 1963
type: TEMPORAL
Source sentences:
text: The initial R-13 (SS-N-4) ballistic missiles could only be launched with the submarine on the surface and the missile raised to the top of the launch tube, but were followed by R-21 (SS-N-5) missiles beginning in 1963, which were launched with the submarine submerged.