Video: TDRS-M takes flight atop Atlas 5

United Launch Alliance is set to retire part of its rocket family Thursday with the final flight of the Delta 4 rocket’s “single stick” configuration, a mission set for liftoff from Cape Canaveral carrying a new GPS navigation satellite into orbit for the U.S. Air Force.

Stormy weather across Florida’s Space Coast forced SpaceX to call off the long-awaited launch of two astronauts aboard the company’s Crew Dragon spacecraft, the first piloted flight to orbit from U.S. soil in nearly nine years.

SpaceX test-fired the Crew Dragon spacecraft’s eight SuperDraco abort engines Wednesday at Cape Canaveral, paving the way for a high-altitude rocket escape test and demonstrating engineers have apparently fixed the problem that triggered an explosion during a similar ground firing in April.