Waterside view of Delta 4 GPS 2F-6 Launch

Gearing up for a predawn blastoff July 31, launch crews have positioned a Delta 4-Heavy rocket in the starting blocks on a seaside launch complex at Cape Canaveral as engineers inside a tightly-controlled clean room a few miles away put the final touches on a NASA probe that will travel closer to the sun than any mission before.

The launch from Cape Canaveral of a top secret spy satellite for the U.S. government was aborted at the last moment early Saturday as its United Launch Alliance Delta 4-Heavy rocket ignited three main engines, a dramatic cutoff of the countdown that will delay the mission by at least one week.

It was 1986 and the U.S. Air Force was on the cusp of something unprecedented in human spaceflight — launching a space shuttle crew from California and paving the way for people to fly true polar missions.