The first launch of a space shuttle from Vandenberg Air Force Base in California has been delayed from Oct. 15 to early 1986, largely because of shuttle problems that have disrupted this year's schedule, it was announced yesterday.

It is the second lengthy delay in the flight of a shuttle from the $2.5 billion oceanside launch complex. The first shuttle launch from Vandenberg originally had been scheduled for August 1984.

The Air Force and the National Aeronautics and Space Administration said in a joint statement that the new launch date for the shuttle Discovery from California is now set for Jan. 29, 1986.

NASA spokesman Debra Rahn said the postponement was required because of delays caused by problems with insulation tiles on the shuttle Challenger and to make sure the secret military cargo will be ready to fly when the shuttle is.

By delaying the Vandenberg flight by 3 1/2 months, NASA will be able to use the shuttle Discovery for two more missions from Cape Canaveral before the spaceship has to be shipped to California. This, Rahn said, will enable NASA to conduct the other 12 shuttle flights this year as planned.

Because of its location, Vandenberg is the only base from which shuttles can fly into north-south orbits crossing the poles. Such polar orbits are ideal for surveillance and weather satellites and for other Earth-watching spacecraft because they fly over the entire globe once every 18 days.