Assertion: unmanned spacecraft | /r/HasProperty | sent around mars
Facets:
value: by the 21st century
type: TEMPORAL
value: into orbit
type: TRANSITIVE-OBJECT
Source sentences:
text: Unmanned spacecraft have been sent into orbit around Saturn, Jupiter, Mars, Venus, and Mercury by the 21st century, and the most distance active spacecraft, Voyager 1 and 2 traveled beyond 100 times the Earth-Sun distance.