A rocket carrying an earth-imaging satellite for civilian and military use has successfully blasted off. The Delta II rocket launched Saturday evening carrying the Thales Alenia-Space COSMO-SkyMed 2 satellite, according to a statement from the base. The satellite will ultimately communicate with three others like it to form an earth-observation system, Air Force spokeswoman Maj. Tina M. Barber-Matthew said. One was launched from Vandenberg earlier this year and the remaining two will be sent into space next year. Saturday's launch initially was scheduled for Dec. 5, but was postponed three times due to bad weather and other problems.